changes

app/apps.py

@@ -7,6 +7,18 @@ class AppConfig(AppConfig):
 
     def ready(self):
         import app.workflow_actions
-        
         from . import signals
         signals.connect_signals()
+
+        # Sử dụng cache.add() của Django để tạo lock, đảm bảo chỉ một worker khởi động scheduler
+        try:
+            from django.core.cache import cache
+            # cache.add() là atomic, chỉ trả về True nếu key được tạo thành công
+            if cache.add("scheduler_lock", "locked", timeout=65):
+                from . import scheduler
+                scheduler.start()
+                print("Scheduler started by this worker.")
+            else:
+                print("Scheduler lock already held by another worker.")
+        except Exception as e:
+            print(f"Failed to start or check scheduler lock: {e}")

app/migrations/0363_alter_transaction_discount_unique_together_batch_job.py

@@ -0,0 +1,36 @@
+# Generated by Django 5.1.7 on 2026-01-23 16:51
+
+import django.db.models.deletion
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('app', '0362_gift'),
+    ]
+
+    operations = [
+        migrations.AlterUniqueTogether(
+            name='transaction_discount',
+            unique_together=set(),
+        ),
+        migrations.CreateModel(
+            name='Batch_Job',
+            fields=[
+                ('id', models.BigAutoField(auto_created=True, primary_key=True, serialize=False, verbose_name='ID')),
+                ('name', models.CharField(max_length=255)),
+                ('cron_schedule', models.CharField(help_text="Cron-like schedule (e.g., '0 0 * * *' for daily at midnight)", max_length=100)),
+                ('parameters', models.JSONField(blank=True, default=dict, help_text='Parameters to find data for the workflow context')),
+                ('is_active', models.BooleanField(db_index=True, default=True)),
+                ('last_run_at', models.DateTimeField(blank=True, null=True)),
+                ('next_run_at', models.DateTimeField(blank=True, db_index=True, null=True)),
+                ('create_time', models.DateTimeField(auto_now_add=True)),
+                ('update_time', models.DateTimeField(auto_now=True)),
+                ('workflow', models.ForeignKey(help_text='Workflow to execute', on_delete=django.db.models.deletion.PROTECT, to='app.workflow')),
+            ],
+            options={
+                'db_table': 'batch_job',
+            },
+        ),
+    ]

app/migrations/0364_alter_user_email.py

@@ -0,0 +1,18 @@
+# Generated by Django 5.1.7 on 2026-01-24 04:07
+
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('app', '0363_alter_transaction_discount_unique_together_batch_job'),
+    ]
+
+    operations = [
+        migrations.AlterField(
+            model_name='user',
+            name='email',
+            field=models.CharField(max_length=100, null=True, unique=True),
+        ),
+    ]

app/migrations/0365_payment_schedule_penalty_paid_and_more.py

@@ -0,0 +1,23 @@
+# Generated by Django 5.1.7 on 2026-01-25 11:20
+
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('app', '0364_alter_user_email'),
+    ]
+
+    operations = [
+        migrations.AddField(
+            model_name='payment_schedule',
+            name='penalty_paid',
+            field=models.DecimalField(decimal_places=2, max_digits=15, null=True),
+        ),
+        migrations.AddField(
+            model_name='payment_schedule',
+            name='penalty_reduce',
+            field=models.DecimalField(decimal_places=2, max_digits=15, null=True),
+        ),
+    ]

app/models.py

@@ -361,7 +361,7 @@ class Payment_Plan(models.Model):
 class User(models.Model):
     username = models.CharField(max_length=50, null=False, unique=True)
     password = models.CharField(max_length=100, null=False)
-    email = models.CharField(max_length=100, null=True)
+    email = models.CharField(max_length=100, null=True, unique=True)
     avatar = models.CharField(max_length=100, null=True)
     fullname = models.CharField(max_length=50, null=False)
     display_name = models.CharField(max_length=50, null=True)
@@ -1702,6 +1702,8 @@ class Payment_Schedule(AutoCodeModel):
     detail = models.JSONField(null=True)
     ovd_days = models.IntegerField(null=True)
     penalty_amount = models.DecimalField(null=True, max_digits=15, decimal_places=2)
+    penalty_paid = models.DecimalField(null=True, max_digits=15, decimal_places=2)
+    penalty_reduce = models.DecimalField(null=True, max_digits=15, decimal_places=2)
     create_time = models.DateTimeField(null=True, auto_now_add=True)
     update_time = models.DateTimeField(null=True, auto_now=True)
 

app/run_batch_jobs.py

@@ -1,104 +0,0 @@
-from django.core.management.base import BaseCommand
-from django.utils import timezone
-from django.db import transaction
-from django.apps import apps
-from croniter import croniter
-import traceback
-
-from app.models import Batch_Job, Batch_Log, Task_Status
-from app.workflow_engine import run_workflow
-from app.workflow_utils import resolve_value
-
-class Command(BaseCommand):
-    help = 'Runs all active batch jobs that are due.'
-
-    def handle(self, *args, **options):
-        self.stdout.write(f"[{timezone.now()}] Starting batch job runner...")
-
-        now = timezone.now()
-        # Lấy các job cần chạy (active và đã đến lúc chạy)
-        due_jobs = Batch_Job.objects.filter(
-            is_active=True,
-            next_run_at__lte=now
-        )
-
-        self.stdout.write(f"Found {due_jobs.count()} due jobs to run.")
-
-        for job in due_jobs:
-            self.stdout.write(f"--- Running job: {job.name} (ID: {job.id}) ---")
-            
-            # Bắt đầu ghi log
-            running_status, _ = Task_Status.objects.get_or_create(code='running', defaults={'name': 'Running'})
-            log = Batch_Log.objects.create(
-                system_date=now.date(),
-                start_time=now,
-                status=running_status
-            )
-
-            try:
-                with transaction.atomic():
-                    # 1. Tìm dữ liệu để xử lý dựa trên tham số của job
-                    params = job.parameters or {}
-                    model_name = params.get("model")
-                    filter_conditions = params.get("filter", {})
-                    context_key = params.get("context_key", "target") # Tên biến trong context workflow
-
-                    if not model_name:
-                        raise ValueError("Job parameters must include a 'model' to query.")
-
-                    TargetModel = apps.get_model('app', model_name)
-                    
-                    # Resolve các giá trị động trong điều kiện filter (ví dụ: $today)
-                    resolved_filters = {k: resolve_value(v, {"now": now, "today": now.date()}) for k, v in filter_conditions.items()}
-                    
-                    targets = TargetModel.objects.filter(**resolved_filters)
-                    self.stdout.write(f"  > Found {targets.count()} target objects to process.")
-
-                    # 2. Thực thi workflow cho từng đối tượng
-                    processed_count = 0
-                    for target_item in targets:
-                        try:
-                            # Chuẩn bị context cho workflow
-                            workflow_context = {
-                                context_key: target_item,
-                                "batch_job": job,
-                                "now": now,
-                            }
-                            run_workflow(
-                                workflow_code=job.workflow.code,
-                                trigger="BATCH_JOB",
-                                context=workflow_context
-                            )
-                            processed_count += 1
-                        except Exception as e:
-                            self.stderr.write(f"  > Error processing target {getattr(target_item, 'pk', 'N/A')} in job {job.name}: {e}")
-                            # Hiện tại, nếu một item lỗi thì bỏ qua và chạy item tiếp theo
-                            # Có thể thay đổi logic để dừng cả job nếu cần
-
-                    # 3. Cập nhật log khi thành công
-                    success_status, _ = Task_Status.objects.get_or_create(code='success', defaults={'name': 'Success'})
-                    log.status = success_status
-                    log.log = {"message": f"Successfully processed {processed_count} of {targets.count()} items."}
-
-            except Exception as e:
-                self.stderr.write(f"!!! Job '{job.name}' failed: {e}")
-                traceback.print_exc()
-                failed_status, _ = Task_Status.objects.get_or_create(code='failed', defaults={'name': 'Failed'})
-                log.status = failed_status
-                log.log = {"error": str(e), "traceback": traceback.format_exc()}
-
-            finally:
-                # 4. Hoàn tất log và đặt lịch chạy lại cho job
-                end_time = timezone.now()
-                log.end_time = end_time
-                log.duration = (end_time - log.start_time).total_seconds()
-                log.save()
-
-                # Đặt lịch cho lần chạy tiếp theo
-                job.last_run_at = now
-                job.next_run_at = croniter(job.cron_schedule, now).get_next(timezone.datetime)
-                job.save()
-
-                self.stdout.write(f"--- Finished job: {job.name}. Next run at: {job.next_run_at} ---")
-
-        self.stdout.write(f"[{timezone.now()}] Batch job runner finished.")

app/scheduler.py

@@ -0,0 +1,162 @@
+import logging
+from django.utils import timezone
+from django.db import transaction
+from django.apps import apps
+from croniter import croniter
+import traceback
+
+from apscheduler.schedulers.background import BackgroundScheduler
+from app.models import Batch_Job, Batch_Log, Task_Status
+from app.workflow_engine import run_workflow
+from app.workflow_utils import resolve_value
+
+# Cấu hình logging cơ bản
+logging.basicConfig(level=logging.INFO)
+logger = logging.getLogger(__name__)
+
+def scan_and_run_due_jobs():
+    """
+    Quét và chạy tất cả các batch job đang active và đã đến hạn.
+    Đồng thời tự động khởi tạo next_run_at cho các job mới.
+    """
+    from django.conf import settings
+    import pytz
+    import datetime
+
+    now = timezone.now()
+
+    # BƯỚC 1: Tìm và khởi tạo các job có next_run_at là null
+    try:
+        uninitialized_jobs = Batch_Job.objects.filter(
+            is_active=True, 
+            next_run_at__isnull=True
+        ).exclude(cron_schedule__isnull=True).exclude(cron_schedule__exact='')
+
+        if uninitialized_jobs.exists():
+            #logger.info(f"Found {uninitialized_jobs.count()} uninitialized jobs. Calculating next run time...")
+            
+            # Lấy timezone của dự án
+            tz = pytz.timezone(settings.TIME_ZONE)
+
+            for job in uninitialized_jobs:
+                try:
+                    schedule_parts = job.cron_schedule.split()
+                    if len(schedule_parts) == 4:
+                        job.cron_schedule = f"{schedule_parts[0]} {schedule_parts[1]} {schedule_parts[2]} {schedule_parts[3]} *"
+                    
+                    cron_parts = job.cron_schedule.split()
+                    if len(cron_parts[0]) > 1 and cron_parts[0].startswith('0'):
+                        cron_parts[0] = str(int(cron_parts[0]))
+                    
+                    corrected_schedule = " ".join(cron_parts)
+
+                    # Xử lý timezone một cách tường minh
+                    # 1. Lấy thời gian hiện tại ở dạng naive (không có thông tin timezone)
+                    naive_now = timezone.localtime(now).replace(tzinfo=None)
+                    # 2. Croniter tính toán ra thời gian naive tiếp theo
+                    naive_next = croniter(corrected_schedule, naive_now).get_next(datetime.datetime)
+                    # 3. Gán lại timezone đúng cho kết quả
+                    aware_next = tz.localize(naive_next)
+                    
+                    job.next_run_at = aware_next
+                    job.save()
+                    #logger.info(f"  -> Initialized job '{job.name}'. Next run at: {job.next_run_at}")
+                except Exception as e:
+                    logger.error(f"  -> Failed to initialize job '{job.name}': {e}")
+    except Exception as e:
+        logger.error(f"Error during job initialization phase: {e}")
+
+
+    # BƯỚC 2: Quét và chạy các job đến hạn như bình thường
+    #logger.info("Scanning for due batch jobs...")
+    
+    # Lấy các job cần chạy (có next_run_at không null và đã đến hạn)
+    due_jobs = Batch_Job.objects.filter(is_active=True, next_run_at__lte=now)
+    
+    if not due_jobs.exists():
+        #logger.info("-> No due jobs found at this time.")
+        return
+
+    #logger.info(f"-> Found {due_jobs.count()} due jobs to run.")
+
+    for job in due_jobs:
+        #logger.info(f"--- Running job: {job.name} (ID: {job.id}) ---")
+        
+        running_status, _ = Task_Status.objects.get_or_create(code='running', defaults={'name': 'Running'})
+        log = Batch_Log.objects.create(
+            system_date=now.date(),
+            start_time=now,
+            status=running_status,
+            log = {"message": f"Starting job {job.name}"}
+        )
+
+        try:
+            with transaction.atomic():
+                params = job.parameters or {}
+                model_name = params.get("model")
+                filter_conditions = params.get("filter", {})
+                context_key = params.get("context_key", "target")
+
+                if not model_name:
+                    raise ValueError("Job parameters must include a 'model' to query.")
+
+                TargetModel = apps.get_model('app', model_name)
+                
+                resolved_filters = {k: resolve_value(v, {"now": now, "today": now.date()}) for k, v in filter_conditions.items()}
+                
+                targets = TargetModel.objects.filter(**resolved_filters)
+                #logger.info(f"  > Found {targets.count()} target objects to process for job '{job.name}'.")
+
+                processed_count = 0
+                for target_item in targets:
+                    try:
+                        workflow_context = {
+                            context_key: target_item,
+                            "batch_job": job,
+                            "now": now,
+                        }
+                        run_workflow(
+                            workflow_code=job.workflow.code,
+                            trigger="create",
+                            context=workflow_context
+                        )
+                        processed_count += 1
+                    except Exception as e:
+                        logger.error(f"  > Error processing target {getattr(target_item, 'pk', 'N/A')} in job {job.name}: {e}", exc_info=True)
+
+                success_status, _ = Task_Status.objects.get_or_create(code='success', defaults={'name': 'Success'})
+                log.status = success_status
+                log.log = {"message": f"Successfully processed {processed_count} of {targets.count()} items."}
+
+        except Exception as e:
+            logger.error(f"!!! Job '{job.name}' failed: {e}", exc_info=True)
+            failed_status, _ = Task_Status.objects.get_or_create(code='failed', defaults={'name': 'Failed'})
+            log.status = failed_status
+            log.log = {"error": str(e), "traceback": traceback.format_exc()}
+
+        finally:
+            end_time = timezone.now()
+            log.end_time = end_time
+            log.duration = (end_time - log.start_time).total_seconds()
+            log.save()
+
+            # Đặt lịch cho lần chạy tiếp theo
+            job.last_run_at = now
+            # Tái sử dụng logic tính toán đã được sửa lỗi timezone
+            tz = pytz.timezone(settings.TIME_ZONE)
+            naive_now = timezone.localtime(now).replace(tzinfo=None)
+            naive_next = croniter(job.cron_schedule, naive_now).get_next(datetime.datetime)
+            job.next_run_at = tz.localize(naive_next)
+            job.save()
+
+            #logger.info(f"--- Finished job: {job.name}. Next run at: {job.next_run_at} ---")
+
+def start():
+    """
+    Khởi động APScheduler và thêm tác vụ quét job.
+    """
+    scheduler = BackgroundScheduler(timezone='Asia/Ho_Chi_Minh')
+    # Chạy tác vụ quét job mỗi 60 giây
+    scheduler.add_job(scan_and_run_due_jobs, 'interval', seconds=60, id='scan_due_jobs_job', replace_existing=True)
+    scheduler.start()
+    #logger.info("APScheduler started... Jobs will be scanned every 60 seconds.")

app/workflow_utils.py

@@ -1,21 +1,32 @@
 import re
-from datetime import datetime
+import math
+from datetime import datetime, date, timedelta
+from decimal import Decimal
 from django.db import models
+from django.apps import apps
 
+# =============================================
+# CORE RESOLVER
+# =============================================
 def resolve_value(expr, context):
     """
-    Giải quyết các placeholder động (dynamic placeholder):
-    - Literal (số, boolean)
-    - Key trực tiếp (ví dụ: "customer_id")
-    - Đường dẫn (ví dụ: "transaction.id")
-    - Template chuỗi (ví dụ: "{customer_id}", "URL/{product_id}")
-    - Hàm hệ thống: $add(a, b), $sub(a, b), $now, $now_iso
+    Universal expression resolver with support for:
+    - Literals (int, float, bool, string)
+    - Template strings: {key}, "text {key} text"
+    - Dotted paths: customer.address.city
+    - Math functions: $add, $sub, $multiply, $divide, $mod, $power, $round, $abs, $min, $max
+    - Date functions: $now, $today, $date_diff, $date_add, $date_format, $date_parse
+    - String functions: $concat, $upper, $lower, $trim, $replace, $substring, $split, $length
+    - Logic functions: $if, $switch, $and, $or, $not
+    - List functions: $append, $agg, $filter, $map, $first, $last, $count, $sum
+    - Lookup functions: $vlookup, $lookup, $get
+    - Nested functions support
     """
     if expr is None:
         return None
 
-    # Direct literal (int, float, bool)
-    if isinstance(expr, (int, float, bool)):
+    # Direct literal types
+    if isinstance(expr, (int, float, bool, Decimal)):
         return expr
     
     if not isinstance(expr, str):
@@ -24,119 +35,460 @@ def resolve_value(expr, context):
     expr = expr.strip()
 
     # =============================================
-    # 1. Hỗ trợ thời gian hiện tại từ server
+    # 1. SYSTEM VARIABLES
     # =============================================
     if expr == "$now":
-        return datetime.now().strftime("%Y-%m-%d %H:%M:%S")  # Format phù hợp với DateTimeField Django
+        return context.get("now", datetime.now())
     
     if expr == "$today":
-        return datetime.now().strftime("%Y-%m-%d")  # Chỉ lấy ngày, đúng format DateField
+        if "today" in context:
+            return context["today"]
+        now_in_context = context.get("now")
+        if isinstance(now_in_context, datetime):
+            return now_in_context.date()
+        return date.today()
     
     if expr == "$now_iso":
-        return datetime.now().isoformat(timespec='seconds')  # 2025-12-21T14:30:45
+        return datetime.now().isoformat(timespec='seconds')
+    
+    if expr == "$timestamp":
+        return int(datetime.now().timestamp())
 
     # =============================================
-    # 2. Hàm toán học: $add(a, b), $sub(a, b), $multiply(a, b)
+    # 2. MATH FUNCTIONS (Support Nested)
     # =============================================
-    func_match = re.match(r"^\$(add|sub|multiply)\(([^,]+),\s*([^)]+)\)$", expr)
-    if func_match:
-        func_name = func_match.group(1)
-        arg1_val = resolve_value(func_match.group(2).strip(), context)
-        arg2_val = resolve_value(func_match.group(3).strip(), context)
+    math_functions = {
+        'add': lambda a, b: a + b,
+        'sub': lambda a, b: a - b,
+        'subtract': lambda a, b: a - b,
+        'multiply': lambda a, b: a * b,
+        'mul': lambda a, b: a * b,
+        'divide': lambda a, b: a / b if b != 0 else 0,
+        'div': lambda a, b: a / b if b != 0 else 0,
+        'mod': lambda a, b: a % b if b != 0 else 0,
+        'power': lambda a, b: a ** b,
+        'pow': lambda a, b: a ** b,
+    }
     
-        try:
-            num1 = float(arg1_val or 0)
-            num2 = float(arg2_val or 0)
-            if func_name == "add":
-                return num1 + num2
-            if func_name == "sub":
-                return num1 - num2
-            if func_name == "multiply":
-                return num1 * num2
-        except (ValueError, TypeError):
-            print(f"      [ERROR] Math function {func_name} failed with values: {arg1_val}, {arg2_val}")
-            return 0
+    for func_name, func in math_functions.items():
+        pattern = rf'^\${func_name}\((.*)\)$'
+        match = re.match(pattern, expr, re.IGNORECASE)
+        if match:
+            args = split_args(match.group(1))
+            if len(args) == 2:
+                a = to_number(resolve_value(args[0], context))
+                b = to_number(resolve_value(args[1], context))
+                return func(a, b)
+
+    # Single-argument math functions
+    single_math = {
+        'round': lambda x, d=0: round(x, int(d)),
+        'abs': lambda x: abs(x),
+        'ceil': lambda x: math.ceil(x),
+        'floor': lambda x: math.floor(x),
+        'sqrt': lambda x: math.sqrt(x) if x >= 0 else 0,
+    }
+    
+    for func_name, func in single_math.items():
+        pattern = rf'^\${func_name}\((.*)\)$'
+        match = re.match(pattern, expr, re.IGNORECASE)
+        if match:
+            args = split_args(match.group(1))
+            if len(args) >= 1:
+                val = to_number(resolve_value(args[0], context))
+                if len(args) == 2 and func_name == 'round':
+                    decimals = to_number(resolve_value(args[1], context))
+                    return func(val, decimals)
+                return func(val)
+
+    # Multi-argument math
+    if re.match(r'^\$(min|max)\(', expr, re.IGNORECASE):
+        match = re.match(r'^\$(min|max)\((.*)\)$', expr, re.IGNORECASE)
+        if match:
+            func_name = match.group(1).lower()
+            args = split_args(match.group(2))
+            values = [to_number(resolve_value(arg, context)) for arg in args]
+            return min(values) if func_name == 'min' else max(values)
 
     # =============================================
-    # 2.1. Hàm xử lý list: $append(list, element)
+    # 3. DATE FUNCTIONS
     # =============================================
-    append_match = re.match(r"^\$append\(([^,]+),\s*(.+)\)$", expr, re.DOTALL)
-    if append_match:
-        list_expr = append_match.group(1).strip()
-        element_expr = append_match.group(2).strip()
+    # $date_diff(date1, date2, unit?)
+    if re.match(r'^\$date_diff\(', expr, re.IGNORECASE):
+        match = re.match(r'^\$date_diff\((.*)\)$', expr, re.IGNORECASE)
+        if match:
+            args = split_args(match.group(1))
+            if len(args) >= 2:
+                raw_d1 = resolve_value(args[0], context)
+                raw_d2 = resolve_value(args[1], context)
                 
-        # 1. Resolve the list
-        target_list = resolve_value(list_expr, context)
-        if target_list is None:
-            target_list = []
+                d1 = to_date(raw_d1)
+                d2 = to_date(raw_d2)
                 
-        # Ensure it's a copy so we don't modify the original context variable directly
-        target_list = list(target_list) 
+                unit = resolve_value(args[2], context).lower() if len(args) > 2 else 'days'
                 
-        # 2. Resolve the element
-        resolved_element = resolve_value(element_expr, context)
+                #print(f"[DEBUG date_diff] raw_d1: {raw_d1}, raw_d2: {raw_d2}") # DEBUG
+                #print(f"[DEBUG date_diff] d1 (datetime): {d1}, d2 (datetime): {d2}") # DEBUG
+                #print(f"[DEBUG date_diff] unit: {unit}") # DEBUG
 
-        if isinstance(resolved_element, str):
-            try:
-                import json
-                element_to_append = json.loads(resolved_element)
-            except json.JSONDecodeError:
-                element_to_append = resolved_element
-        else:
-            element_to_append = resolved_element
+                if not (d1 and d2):
+                    #print("[DEBUG date_diff] One or both dates are invalid. Returning 0.") # DEBUG
+                    return 0
                 
-        target_list.append(element_to_append)
-        return target_list
+                # Ensure we are comparing date objects, ignoring time
+                d1_date_only = d1.date()
+                d2_date_only = d2.date()
                 
-    # =============================================
-    # 2.2. Hàm tổng hợp list: $agg(list, operation, field?)
-    # =============================================
-    agg_match = re.match(r"^\$agg\(([^,]+),\s*'([^']+)'(?:,\s*['\"]?([^'\"]+)['\"]?)?\)$", expr.strip())
-    if agg_match:
-        list_expr = agg_match.group(1).strip()
-        operation = agg_match.group(2).strip()
-        field_expr = agg_match.group(3).strip() if agg_match.group(3) else None
+                #print(f"[DEBUG date_diff] d1_date_only: {d1_date_only}, d2_date_only: {d2_date_only}") # DEBUG
 
-        # 1. Resolve the list
-        target_list = resolve_value(list_expr, context)
-        if target_list is None:
-            target_list = []
+                if unit == 'days':
+                    delta_days = (d1_date_only - d2_date_only).days
+                    #print(f"[DEBUG date_diff] Calculated delta_days: {delta_days}. Returning {delta_days}.") # DEBUG
+                    return delta_days
+                elif unit == 'months':
+                    delta_months = (d1_date_only.year - d2_date_only.year) * 12 + d1_date_only.month - d2_date_only.month
+                    #print(f"[DEBUG date_diff] Calculated delta_months: {delta_months}. Returning {delta_months}.") # DEBUG
+                    return delta_months
+                elif unit == 'years':
+                    delta_years = d1_date_only.year - d2_date_only.year
+                    #print(f"[DEBUG date_diff] Calculated delta_years: {delta_years}. Returning {delta_years}.") # DEBUG
+                    return delta_years
                 
-        if not isinstance(target_list, list):
-            return 0
-
-        # 2. Perform operation
-        if operation == 'count':
-            return len(target_list)
-        
-        if operation == 'sum':
-            if not field_expr:
+                #print(f"[DEBUG date_diff] Unit '{unit}' not recognized. Returning 0.") # DEBUG
                 return 0
 
-            total = 0
-            for item in target_list:
-                value = 0
-                if isinstance(item, dict):
-                    value = item.get(field_expr)
-                else:
-                    value = getattr(item, field_expr, 0)
+    # $date_add(date, amount, unit?)
+    if re.match(r'^\$date_add\(', expr, re.IGNORECASE):
+        match = re.match(r'^\$date_add\((.*)\)$', expr, re.IGNORECASE)
+        if match:
+            args = split_args(match.group(1))
+            if len(args) >= 2:
+                base_date = to_date(resolve_value(args[0], context))
+                amount = to_number(resolve_value(args[1], context))
+                unit = resolve_value(args[2], context).lower() if len(args) > 2 else 'days'
+                
+                if base_date:
+                    # Ensure base_date is datetime
+                    if isinstance(base_date, date) and not isinstance(base_date, datetime):
+                        base_date = datetime.combine(base_date, datetime.min.time())
+                    
+                    if unit == 'days':
+                        result = base_date + timedelta(days=int(amount))
+                    elif unit == 'months':
+                        month = base_date.month + int(amount)
+                        year = base_date.year + (month - 1) // 12
+                        month = ((month - 1) % 12) + 1
+                        result = base_date.replace(year=year, month=month)
+                    elif unit == 'years':
+                        result = base_date.replace(year=base_date.year + int(amount))
+                    elif unit == 'hours':
+                        result = base_date + timedelta(hours=int(amount))
+                    else:
+                        result = base_date + timedelta(days=int(amount))
+                    
+                    return result.isoformat() if isinstance(result, datetime) else result.strftime("%Y-%m-%d")
+
+    # $date_format(date, format)
+    if re.match(r'^\$date_format\(', expr, re.IGNORECASE):
+        match = re.match(r'^\$date_format\((.*)\)$', expr, re.IGNORECASE)
+        if match:
+            args = split_args(match.group(1))
+            if len(args) == 2:
+                dt = to_date(resolve_value(args[0], context))
+                fmt = resolve_value(args[1], context).strip('\'"')
+                if dt:
+                    return dt.strftime(fmt)
+
+    # $date_parse(string, format)
+    if re.match(r'^\$date_parse\(', expr, re.IGNORECASE):
+        match = re.match(r'^\$date_parse\((.*)\)$', expr, re.IGNORECASE)
+        if match:
+            args = split_args(match.group(1))
+            if len(args) >= 1:
+                date_str = str(resolve_value(args[0], context))
+                fmt = resolve_value(args[1], context).strip('\'"') if len(args) > 1 else "%Y-%m-%d"
+                try:
+                    return datetime.strptime(date_str, fmt).strftime("%Y-%m-%d")
+                except:
+                    return None
+
+    # =============================================
+    # 4. STRING FUNCTIONS
+    # =============================================
+    # $concat(str1, str2, ...)
+    if re.match(r'^\$concat\(', expr, re.IGNORECASE):
+        match = re.match(r'^\$concat\((.*)\)$', expr, re.IGNORECASE)
+        if match:
+            args = split_args(match.group(1))
+            return ''.join(str(resolve_value(arg, context) or '') for arg in args)
+
+    # $upper, $lower, $trim
+    string_single = {
+        'upper': lambda s: str(s).upper(),
+        'lower': lambda s: str(s).lower(),
+        'trim': lambda s: str(s).strip(),
+        'length': lambda s: len(str(s)),
+    }
+    
+    for func_name, func in string_single.items():
+        pattern = rf'^\${func_name}\((.*)\)$'
+        match = re.match(pattern, expr, re.IGNORECASE)
+        if match:
+            arg = resolve_value(match.group(1).strip(), context)
+            return func(arg)
+
+    # $replace(text, old, new)
+    if re.match(r'^\$replace\(', expr, re.IGNORECASE):
+        match = re.match(r'^\$replace\((.*)\)$', expr, re.IGNORECASE)
+        if match:
+            args = split_args(match.group(1))
+            if len(args) == 3:
+                text = str(resolve_value(args[0], context))
+                old = str(resolve_value(args[1], context)).strip('\'"')
+                new = str(resolve_value(args[2], context)).strip('\'"')
+                return text.replace(old, new)
+
+    # $substring(text, start, length?)
+    if re.match(r'^\$substring\(', expr, re.IGNORECASE):
+        match = re.match(r'^\$substring\((.*)\)$', expr, re.IGNORECASE)
+        if match:
+            args = split_args(match.group(1))
+            if len(args) >= 2:
+                text = str(resolve_value(args[0], context))
+                start = int(to_number(resolve_value(args[1], context)))
+                length = int(to_number(resolve_value(args[2], context))) if len(args) > 2 else None
+                return text[start:start+length] if length else text[start:]
+
+    # $split(text, delimiter)
+    if re.match(r'^\$split\(', expr, re.IGNORECASE):
+        match = re.match(r'^\$split\((.*)\)$', expr, re.IGNORECASE)
+        if match:
+            args = split_args(match.group(1))
+            if len(args) == 2:
+                text = str(resolve_value(args[0], context))
+                delimiter = str(resolve_value(args[1], context)).strip('\'"')
+                return text.split(delimiter)
+
+    # =============================================
+    # 5. LOGIC FUNCTIONS
+    # =============================================
+    # $if(condition, true_value, false_value)
+    if re.match(r'^\$if\(', expr, re.IGNORECASE):
+        match = re.match(r'^\$if\((.*)\)$', expr, re.IGNORECASE)
+        if match:
+            args = split_args(match.group(1))
+            if len(args) == 3:
+                condition = resolve_value(args[0], context)
+                return resolve_value(args[1], context) if condition else resolve_value(args[2], context)
+
+    # $switch(value, case1, result1, case2, result2, ..., default)
+    if re.match(r'^\$switch\(', expr, re.IGNORECASE):
+        match = re.match(r'^\$switch\((.*)\)$', expr, re.IGNORECASE)
+        if match:
+            args = split_args(match.group(1))
+            if len(args) >= 2:
+                value = resolve_value(args[0], context)
+                for i in range(1, len(args) - 1, 2):
+                    if i + 1 < len(args):
+                        case = resolve_value(args[i], context)
+                        if value == case:
+                            return resolve_value(args[i + 1], context)
+                # Default value is last arg if odd number of args
+                if len(args) % 2 == 0:
+                    return resolve_value(args[-1], context)
+
+    # $and, $or, $not
+    if re.match(r'^\$and\(', expr, re.IGNORECASE):
+        match = re.match(r'^\$and\((.*)\)$', expr, re.IGNORECASE)
+        if match:
+            args = split_args(match.group(1))
+            return all(resolve_value(arg, context) for arg in args)
+
+    if re.match(r'^\$or\(', expr, re.IGNORECASE):
+        match = re.match(r'^\$or\((.*)\)$', expr, re.IGNORECASE)
+        if match:
+            args = split_args(match.group(1))
+            return any(resolve_value(arg, context) for arg in args)
+
+    if re.match(r'^\$not\(', expr, re.IGNORECASE):
+        match = re.match(r'^\$not\((.*)\)$', expr, re.IGNORECASE)
+        if match:
+            arg = resolve_value(match.group(1).strip(), context)
+            return not arg
+
+    # =============================================
+    # 6. LIST/ARRAY FUNCTIONS
+    # =============================================
+    # $append(list, element)
+    if re.match(r'^\$append\(', expr, re.IGNORECASE):
+        match = re.match(r'^\$append\((.*)\)$', expr, re.IGNORECASE)
+        if match:
+            args = split_args(match.group(1))
+            if len(args) == 2:
+                target_list = resolve_value(args[0], context)
+                element = resolve_value(args[1], context)
+                if not isinstance(target_list, list):
+                    target_list = []
+                result = list(target_list)
+                result.append(element)
+                return result
+
+    # $first(list), $last(list)
+    if re.match(r'^\$(first|last)\(', expr, re.IGNORECASE):
+        match = re.match(r'^\$(first|last)\((.*)\)$', expr, re.IGNORECASE)
+        if match:
+            func_name = match.group(1).lower()
+            lst = resolve_value(match.group(2).strip(), context)
+            if isinstance(lst, list) and len(lst) > 0:
+                return lst[0] if func_name == 'first' else lst[-1]
+
+    # $count(list)
+    if re.match(r'^\$count\(', expr, re.IGNORECASE):
+        match = re.match(r'^\$count\((.*)\)$', expr, re.IGNORECASE)
+        if match:
+            lst = resolve_value(match.group(1).strip(), context)
+            return len(lst) if isinstance(lst, list) else 0
+
+    # $agg(list, operation, field?)
+    if re.match(r'^\$agg\(', expr, re.IGNORECASE):
+        match = re.match(r'^\$agg\(([^,]+),\s*[\'"]([^\'\"]+)[\'"](?:,\s*[\'"]?([^\'\")]+)[\'"]?)?\)$', expr)
+        if match:
+            list_expr = match.group(1).strip()
+            operation = match.group(2).strip()
+            field_expr = match.group(3).strip() if match.group(3) else None
+
+            target_list = resolve_value(list_expr, context)
+            if not isinstance(target_list, list):
+                return 0
+
+            if operation == 'count':
+                return len(target_list)
+            
+            if operation == 'sum':
+                if not field_expr:
+                    return sum(to_number(item) for item in target_list)
+                total = 0
+                for item in target_list:
+                    value = item.get(field_expr) if isinstance(item, dict) else getattr(item, field_expr, 0)
+                    total += to_number(value)
+                return total
+            
+            if operation in ['min', 'max', 'avg']:
+                values = []
+                for item in target_list:
+                    if field_expr:
+                        value = item.get(field_expr) if isinstance(item, dict) else getattr(item, field_expr, 0)
+                    else:
+                        value = item
+                    values.append(to_number(value))
+                
+                if not values:
+                    return 0
+                if operation == 'min':
+                    return min(values)
+                elif operation == 'max':
+                    return max(values)
+                elif operation == 'avg':
+                    return sum(values) / len(values)
+
+    # =============================================
+    # 7. LOOKUP FUNCTIONS
+    # =============================================
+    # $vlookup(lookup_value, model_name, lookup_field, return_field)
+    if re.match(r'^\$vlookup\(', expr, re.IGNORECASE):
+        match = re.match(r'^\$vlookup\((.*)\)$', expr, re.IGNORECASE)
+        if match:
+            args = split_args(match.group(1))
+            if len(args) == 4:
+                lookup_value = resolve_value(args[0], context)
+                model_name = resolve_value(args[1], context).strip('\'"')
+                lookup_field = resolve_value(args[2], context).strip('\'"')
+                return_field = resolve_value(args[3], context).strip('\'"')
                 
                 try:
-                    total += float(value or 0)
-                except (ValueError, TypeError):
+                    Model = apps.get_model('app', model_name)
+                    obj = Model.objects.filter(**{lookup_field: lookup_value}).first()
+                    if obj:
+                        return getattr(obj, return_field, None)
+                except:
                     pass
-            return total
 
-        print(f"      [ERROR] Unknown $agg operation: {operation}")
-        return 0
+    # $lookup(model_name, field, value)
+    if re.match(r'^\$lookup\(', expr, re.IGNORECASE):
+        match = re.match(r'^\$lookup\((.*)\)$', expr, re.IGNORECASE)
+        if match:
+            args = split_args(match.group(1))
+            if len(args) == 3:
+                model_name = resolve_value(args[0], context).strip('\'"')
+                field = resolve_value(args[1], context).strip('\'"')
+                value = resolve_value(args[2], context)
+                
+                try:
+                    Model = apps.get_model('app', model_name)
+                    return Model.objects.filter(**{field: value}).first()
+                except:
+                    pass
+
+    # $get(dict_or_object, key, default?)
+    if re.match(r'^\$get\(', expr, re.IGNORECASE):
+        match = re.match(r'^\$get\((.*)\)$', expr, re.IGNORECASE)
+        if match:
+            args = split_args(match.group(1))
+            if len(args) >= 2:
+                obj = resolve_value(args[0], context)
+                key = resolve_value(args[1], context)
+                default = resolve_value(args[2], context) if len(args) > 2 else None
+                
+                if isinstance(obj, dict):
+                    return obj.get(key, default)
+                else:
+                    return getattr(obj, key, default)
 
     # =============================================
-    # 3. Helper: Lấy giá trị từ context theo đường dẫn dotted
+    # 8. COMPARISON OPERATORS
+    # =============================================
+    # $eq, $ne, $gt, $gte, $lt, $lte, $in, $contains
+    comparisons = {
+        'eq': lambda a, b: a == b,
+        'ne': lambda a, b: a != b,
+        'gt': lambda a, b: a > b,
+        'gte': lambda a, b: a >= b,
+        'lt': lambda a, b: a < b,
+        'lte': lambda a, b: a <= b,
+        'in': lambda a, b: a in b,
+        'contains': lambda a, b: b in a,
+    }
+    
+    for op_name, op_func in comparisons.items():
+        pattern = rf'^\${op_name}\('
+        if re.match(pattern, expr, re.IGNORECASE):
+            match = re.match(rf'^\${op_name}\((.*)\)$', expr, re.IGNORECASE)
+            if match:
+                args = split_args(match.group(1))
+                if len(args) == 2:
+                    a = resolve_value(args[0], context)
+                    b = resolve_value(args[1], context)
+                    return op_func(a, b)
+
+    # =============================================
+    # 9. HELPER: Get context value (dotted path)
     # =============================================
     def get_context_value(key_path):
-        if "." not in key_path:
-            return context.get(key_path)
+        if not key_path:
+            return None
         
+        # Check if numeric literal
+        if re.match(r"^-?\d+(\.\d+)?$", key_path):
+            return float(key_path)
+
+        # Simple key
+        if "." not in key_path:
+            val = context.get(key_path)
+            if isinstance(val, Decimal):
+                return float(val)
+            return val
+
+        # Dotted path
         root, *rest = key_path.split(".")
         val = context.get(root)
         
@@ -144,54 +496,46 @@ def resolve_value(expr, context):
             if val is None:
                 return None
             
-            # 1. Xử lý truy cập index mảng, ví dụ: payment_plan[0]
+            # Array notation: field[0]
             array_match = re.match(r"(\w+)\[(\d+)\]", r)
             if array_match:
                 attr_name = array_match.group(1)
                 index = int(array_match.group(2))
-                # Lấy list/queryset
                 val = getattr(val, attr_name, None) if not isinstance(val, dict) else val.get(attr_name)
                 try:
-                    if hasattr(val, 'all'): # Django QuerySet/Manager
-                        val = val[index]
-                    else: # List thông thường
-                        val = val[index]
-                except (IndexError, TypeError, KeyError):
+                    val = val[index]
+                except:
                     return None
             else:
-                # 2. Xử lý truy cập thuộc tính hoặc dict key
                 if isinstance(val, dict):
                     val = val.get(r)
                 else:
                     val = getattr(val, r, None)
             
-            # 3. Hỗ trợ tự động lấy bản ghi đầu tiên nếu là Manager (1-n)
+            # Auto-fetch first() for QuerySet
             if hasattr(val, 'all') and not isinstance(val, models.Model):
                 val = val.first()
         
+        if isinstance(val, Decimal):
+            return float(val)
         return val
 
     # =============================================
-    # 4. Xử lý placeholder kiểu {key} hoặc {obj.field}
+    # 10. TEMPLATE STRING PROCESSING
     # =============================================
     pattern = re.compile(r"\{(\w+(\.\w+)*)\}")
     if pattern.search(expr):
-        # Trường hợp toàn bộ expr là một placeholder duy nhất: {customer_id}
         single_match = pattern.fullmatch(expr)
         if single_match:
-            key = single_match.group(1)
-            return get_context_value(key)
+            return get_context_value(single_match.group(1))
 
-        # Trường hợp chuỗi có nhiều placeholder: "Hello {customer.name}"
         def replace_match(match):
-            key = match.group(1)
-            val = get_context_value(key)
+            val = get_context_value(match.group(1))
             return str(val) if val is not None else ""
-
         return pattern.sub(replace_match, expr)
 
     # =============================================
-    # 5. Hỗ trợ $last_result và $last_result.field
+    # 11. SUPPORT $last_result
     # =============================================
     if expr.startswith("$last_result"):
         _, _, field = expr.partition(".")
@@ -203,12 +547,81 @@ def resolve_value(expr, context):
         return getattr(last_res, field, None) if not isinstance(last_res, dict) else last_res.get(field)
 
     # =============================================
-    # 6. Dotted path trực tiếp: customer.name hoặc obj in context
+    # 12. DOTTED PATH OR DIRECT CONTEXT KEY
     # =============================================
+    if re.match(r"^-?\d+(\.\d+)?$", expr):
+        return float(expr)
+
     if "." in expr or expr in context:
         return get_context_value(expr)
 
-    # =============================================
-    # 7. Trả về nguyên expr nếu không match gì
-    # =============================================
     return expr
+
+
+# =============================================
+# HELPER FUNCTIONS
+# =============================================
+def split_args(content):
+    """
+    Split function arguments respecting nested parentheses and quotes.
+    Example: "a, $add(b, c), 'd'" -> ["a", "$add(b, c)", "'d'"]
+    """
+    args = []
+    current = []
+    depth = 0
+    in_quote = None
+    
+    for char in content:
+        if char in ('"', "'") and (not in_quote or in_quote == char):
+            in_quote = None if in_quote else char
+            current.append(char)
+        elif in_quote:
+            current.append(char)
+        elif char == '(':
+            depth += 1
+            current.append(char)
+        elif char == ')':
+            depth -= 1
+            current.append(char)
+        elif char == ',' and depth == 0:
+            args.append(''.join(current).strip())
+            current = []
+        else:
+            current.append(char)
+    
+    if current:
+        args.append(''.join(current).strip())
+    
+    return args
+
+
+def to_number(value, default=0):
+    """Convert value to number, return default if fails."""
+    if value is None or value == '':
+        return default
+    try:
+        return float(value)
+    except (ValueError, TypeError):
+        return default
+
+
+def to_date(value):
+    """Convert value to datetime object."""
+    #print(f"[DEBUG to_date] Input value: {value} (type: {type(value)})") # DEBUG
+    if isinstance(value, datetime):
+        #print(f"[DEBUG to_date] Output (datetime): {value}") # DEBUG
+        return value
+    if isinstance(value, date):
+        result = datetime.combine(value, datetime.min.time())
+        #print(f"[DEBUG to_date] Output (date -> datetime): {result}") # DEBUG
+        return result
+    if isinstance(value, str):
+        for fmt in ("%Y-%m-%d %H:%M:%S", "%Y-%m-%d", "%d/%m/%Y", "%Y-%m-%dT%H:%M:%S"):
+            try:
+                result = datetime.strptime(value.split('.')[0], fmt)
+                #print(f"[DEBUG to_date] Output (str -> datetime): {result}") # DEBUG
+                return result
+            except:
+                continue
+    #print(f"[DEBUG to_date] Output (None): None") # DEBUG
+    return None