"""
===============================================================================
FILE: services/tasks/repository.py
PROJECT: SCUD Orion AI (Unified Architecture)
MODULE: services / tasks
ROLE: Низкоуровневые операции к таблице tasks в SQLite (CRUD).

AI-CONTEXT-ANCHORS:
  - ANCHOR[TASK_REPO_GET]: Выборка задач с фильтрацией по статусу и пользователю.
  - ANCHOR[TASK_REPO_ADD]: Вставка новой задачи со сквозным ID.
  - ANCHOR[TASK_REPO_UPDATE]: Обновление реквизитов и статуса задачи.
  - ANCHOR[TASK_REPO_DELETE]: Удаление задачи по числовому или строковому ID.
===============================================================================
"""

import re
from typing import List, Dict, Any, Optional
from core.connection import get_connection


def normalize_task_id(task_id_input: str) -> str:
    """Нормализует идентификатор задачи к формату TASK-XX."""
    if not task_id_input:
        return ""
    clean_id = str(task_id_input).strip().upper().replace("TASK-", "").replace("TASK", "").replace("#", "")
    if clean_id.isdigit():
        num = int(clean_id)
        return f"TASK-{num:02d}" if num < 100 else f"TASK-{num:03d}"
    return f"TASK-{clean_id}"


# ANCHOR[TASK_REPO_GET]
def repo_get_tasks(user_id: int, status: Optional[str] = None) -> List[Dict[str, Any]]:
    """Получает список задач пользователя с опциональной фильтрацией по статусу."""
    conn = get_connection(row_factory=True)
    cursor = conn.cursor()
    
    if status and status.upper() != "ALL":
        target_status = status.upper()
        if target_status in ["PROGRESS", "В РАБОТЕ"]: 
            target_status = "IN_PROGRESS"
        elif target_status in ["DONE", "ГОТОВО"]: 
            target_status = "COMPLETED"
        elif target_status in ["PLANNED", "ПЛАНЫ"]: 
            target_status = "BACKLOG"
        
        cursor.execute("""
            SELECT id, task_id, module, title, priority, status, due_date, created_at 
            FROM tasks 
            WHERE user_id = ? AND (status = ? OR (status = 'BACKLOG' AND ? = 'PLANNED'))
            ORDER BY id DESC
        """, (user_id, target_status, target_status))
    else:
        cursor.execute("""
            SELECT id, task_id, module, title, priority, status, due_date, created_at 
            FROM tasks 
            WHERE user_id = ?
            ORDER BY id DESC
        """, (user_id,))
        
    rows = cursor.fetchall()
    conn.close()
    return [dict(r) for r in rows]


# ANCHOR[TASK_REPO_ADD]
def repo_add_task(
    user_id: int, 
    module: str, 
    title: str, 
    priority: str = "MEDIUM", 
    due_date: Optional[str] = None,
    status: str = "BACKLOG"
) -> Dict[str, Any]:
    """Добавляет новую задачу в SQLite с автогенерацией порядкового TASK-ID."""
    conn = get_connection()
    cursor = conn.cursor()
    cursor.execute("SELECT MAX(id) FROM tasks")
    max_id = cursor.fetchone()[0] or 0
    new_task_id = f"TASK-{(max_id + 1):02d}"

    target_status = status.upper() if status else "BACKLOG"
    if target_status in ["PROGRESS", "В РАБОТЕ"]: 
        target_status = "IN_PROGRESS"
    elif target_status in ["DONE", "ГОТОВО"]: 
        target_status = "COMPLETED"
    elif target_status in ["PLANNED", "ПЛАНЫ", "BACKLOG"]: 
        target_status = "BACKLOG"

    cursor.execute("""
        INSERT INTO tasks (task_id, module, title, priority, status, due_date, user_id)
        VALUES (?, ?, ?, ?, ?, ?, ?)
    """, (new_task_id, module or "general", title.strip(), priority.upper(), target_status, due_date, user_id))
    conn.commit()
    conn.close()
    return {"status": "success", "task_id": new_task_id, "id": max_id + 1}


# ANCHOR[TASK_REPO_UPDATE]
def repo_update_task(
    user_id: int, 
    task_id: str, 
    title: Optional[str] = None, 
    priority: Optional[str] = None, 
    status: Optional[str] = None, 
    due_date: Optional[str] = None
) -> Dict[str, Any]:
    """Комплексное обновление атрибутов задачи."""
    conn = get_connection()
    cursor = conn.cursor()
    
    clean_num = re.sub(r'\D', '', str(task_id))
    formatted_id = normalize_task_id(task_id)

    updates = []
    params = []

    if title is not None and title.strip():
        updates.append("title = ?")
        params.append(title.strip())

    if priority is not None and priority.strip():
        updates.append("priority = ?")
        params.append(priority.strip().upper())

    if status is not None and status.strip():
        target_status = status.strip().upper()
        if target_status in ["PROGRESS", "В РАБОТЕ"]: 
            target_status = "IN_PROGRESS"
        elif target_status in ["DONE", "ГОТОВО"]: 
            target_status = "COMPLETED"
        elif target_status in ["PLANNED", "ПЛАНЫ"]: 
            target_status = "BACKLOG"
        updates.append("status = ?")
        params.append(target_status)

    if due_date is not None:
        updates.append("due_date = ?")
        params.append(due_date.strip() if due_date.strip() else None)

    if not updates:
        conn.close()
        return {"status": "success", "message": "Нет данных для обновления"}

    params.extend([clean_num, formatted_id, f"%{task_id.strip()}", user_id])
    sql = f"""
        UPDATE tasks 
        SET {', '.join(updates)} 
        WHERE (id = ? OR UPPER(task_id) = ? OR task_id LIKE ?) AND user_id = ?
    """
    cursor.execute(sql, params)
    rows_affected = cursor.rowcount
    conn.commit()
    conn.close()

    if rows_affected == 0:
        return {"error": f"Задача {task_id} не найдена или принадлежит другому пользователю"}
        
    return {"status": "success", "message": f"Задача #{task_id} успешно обновлена"}


# ANCHOR[TASK_REPO_DELETE]
def repo_delete_task(user_id: int, task_id: str) -> Dict[str, Any]:
    """Удаляет задачу по номеру ID."""
    conn = get_connection()
    cursor = conn.cursor()
    clean_num = re.sub(r'\D', '', str(task_id))
    formatted_id = normalize_task_id(task_id)
    
    cursor.execute("""
        DELETE FROM tasks 
        WHERE (id = ? OR UPPER(task_id) = ? OR task_id LIKE ?) AND user_id = ?
    """, (clean_num, formatted_id, f"%{task_id.strip()}", user_id))
    
    deleted = cursor.rowcount
    conn.commit()
    conn.close()
    
    if deleted == 0:
        return {"error": f"Задача {task_id} не найдена"}
    return {"status": "success", "message": f"Задача #{task_id} удалена"}