from flask import request, jsonify, render_template
from flask_login import current_user
from app import db
from app.models import Task, WorkDetail
from app.service.logger import log_activity


def recalc_task(task):
    rate = float(task.rate or 0)
    qty = float(task.qty or 0)

    prev_qty = float(task.previous_billed_qty or 0)
    ra_qty = float(task.in_this_ra_bill_qty or 0)

    task.previous_billing_amount = round(prev_qty * rate, 2)
    task.in_this_ra_billing_amount = round(ra_qty * rate, 2)

    task.cumulative_billed_qty = round(prev_qty + ra_qty, 2)
    task.cumulative_billed_amount = round(task.cumulative_billed_qty * rate, 2)

    if task.cumulative_billed_qty > qty:
        task.variation_qty = round(task.cumulative_billed_qty - qty, 2)
    else:
        task.variation_qty = 0

    task.variation_amount = round(task.variation_qty * rate, 2)



def update_tasks_controller():
    try:
        updates = request.get_json()
        update_count = 0

        formula_fields = [
            "previous_billing_amount",
            "in_this_ra_billing_amount",
            "cumulative_billed_qty",
            "cumulative_billed_amount",
            "variation_qty",
            "variation_amount"
        ]

        for key, new_value in updates.items():

            if '_' not in key:
                continue

            field_name, task_id_str = key.rsplit('_', 1)

            if not task_id_str.isdigit():
                continue

            task = Task.query.get(int(task_id_str))

            if task:

                if field_name in formula_fields:
                    continue

                current_value = getattr(task, field_name, None)

                if str(current_value) != str(new_value):
                    setattr(task, field_name, new_value)

                    recalc_task(task)

                    update_count += 1

                    log_activity(
                        current_user.username,
                        "Task Update",
                        f"Task ID {task.id} - {field_name} changed to {new_value}"
                    )

        if update_count > 0:
            db.session.commit()

            log_activity(
                current_user.username,
                "Database Commit",
                f"{update_count} task field(s) updated"
            )

            return jsonify({'message': f'count: {update_count} field(s) updated.'})

        return jsonify({'message': 'No fields were updated.'})

    except Exception as e:
        log_activity(current_user.username, "Error", str(e))
        return jsonify({'error': 'Update failed'}), 500
    
    
    # # Update tasks route
# @main.route('/update_tasks', methods=['POST'])
# @login_required
# def update_tasks():
#     try:
#         updates = request.get_json()
#         update_count = 0

#         for key, new_value in updates.items():
#             if '_' not in key:
#                 continue

#             field_name, task_id_str = key.rsplit('_', 1)
#             if not task_id_str.isdigit():
#                 continue

#             task_id = int(task_id_str)
#             task = db.session.query(Task).filter_by(id=task_id).first()

#             if task:
#                 current_value = getattr(task, field_name, None)
#                 if current_value != new_value:
#                     setattr(task, field_name, new_value)
#                     update_count += 1
#                     log_activity(current_user.username, "Task Update", f"Task ID {task.id} - {field_name} changed to {new_value}")

#         if update_count > 0:
#             db.session.commit()
#             log_activity(current_user.username, "Database Commit", f"{update_count} task field(s) updated")
#             return jsonify({'message': f'count: {update_count} field(s) updated.'})
#         else:
#             return jsonify({'message': 'No fields were updated.'})

#     except Exception as e:
#         log_activity(current_user.username, "Error", f"Update tasks error: {str(e)}")
#         return jsonify({'error': 'An error occurred while updating tasks.'}), 500


def display_tasks_controller():

    work_details = WorkDetail.query.order_by(
        WorkDetail.uploaded_at.desc()
    ).first()

    if not work_details:
        log_activity(current_user.username, "Tasks View", "No work details")
        return "No work details available.", 404

    tasks = Task.query.filter_by(
        district=work_details.district,
        village_name=work_details.name_of_village,
        block_name=work_details.block
    ).order_by(Task.uploaded_at.desc()).all()

    grouped_tasks = []
    current_main_task = None

    for task in tasks:

        task_data = {
            "id": task.id,
            "task_name": task.task_name,
            "unit": task.unit,
            "qty": task.qty,
            "rate": task.rate,
            "boq_amount": task.boq_amount,
            "previous_billed_qty": task.previous_billed_qty,
            "previous_billing_amount": task.previous_billing_amount,
            "in_this_ra_bill_qty": task.in_this_ra_bill_qty,
            "in_this_ra_billing_amount": task.in_this_ra_billing_amount,
            "cumulative_billed_qty": task.cumulative_billed_qty,
            "cumulative_billed_amount": task.cumulative_billed_amount,
            "variation_qty": task.variation_qty,
            "variation_amount": task.variation_amount,
            "remark": task.remark,
            "district": task.district
        }

        if task.serial_number:
            task_data["subtasks"] = []
            grouped_tasks.append(task_data)
            current_main_task = task_data
        elif current_main_task:
            current_main_task["subtasks"].append(task_data)

    log_activity(
        current_user.username,
        "Tasks View",
        f"{work_details.name_of_village}, {work_details.block}"
    )

    return render_template(
        'tasks_display.html',
        work_details=work_details,
        grouped_tasks=grouped_tasks
    )