import time
import json
import uuid
from fastapi import APIRouter, HTTPException, Depends, Header
from pydantic import BaseModel
from typing import Optional, Any, Dict
from app.models.user import get_db_connection
from app.api.v1.auth import get_current_user, decode_token

router = APIRouter()

class SaveProjectRequest(BaseModel):
    name: str
    data_json: str

class SaveTempProjectRequest(BaseModel):
    data_json: str

def get_optional_user(authorization: Optional[str] = Header(None)) -> Optional[dict]:
    if authorization and authorization.startswith("Bearer "):
        token = authorization.split(" ")[1]
        return decode_token(token)
    return None

@router.post("/temp")
async def save_temp_project(req: SaveTempProjectRequest, current_user: Optional[dict] = Depends(get_optional_user)):
    user_id = current_user["user_id"] if current_user else "anonymous"
    conn = get_db_connection()
    cursor = conn.cursor()
    
    size_bytes = len(req.data_json.encode("utf-8"))
    now = time.time()
    temp_id = f"temp_{user_id}"
    
    cursor.execute("""
    INSERT INTO projects (id, user_id, name, data_json, is_temp, size_bytes, updated_at)
    VALUES (?, ?, 'Dự án tạm chưa lưu', ?, 1, ?, ?)
    ON CONFLICT(id) DO UPDATE SET data_json = excluded.data_json, size_bytes = excluded.size_bytes, updated_at = excluded.updated_at
    """, (temp_id, user_id, req.data_json, size_bytes, now))
    
    conn.commit()
    conn.close()
    return {"message": "Đã lưu dự án tạm tự động", "updated_at": now}

@router.get("/temp")
async def get_temp_project(current_user: Optional[dict] = Depends(get_optional_user)):
    user_id = current_user["user_id"] if current_user else "anonymous"
    temp_id = f"temp_{user_id}"
    
    conn = get_db_connection()
    cursor = conn.cursor()
    cursor.execute("SELECT data_json, updated_at FROM projects WHERE id = ? AND is_temp = 1", (temp_id,))
    row = cursor.fetchone()
    conn.close()
    
    if not row:
        return {"has_temp": False}
        
    return {
        "has_temp": True,
        "data_json": row["data_json"],
        "updated_at": row["updated_at"]
    }

@router.post("/cloud")
async def save_cloud_project(req: SaveProjectRequest, current_user: dict = Depends(get_current_user)):
    user_id = current_user["user_id"]
    conn = get_db_connection()
    cursor = conn.cursor()
    
    cursor.execute("SELECT storage_limit_mb FROM user_quotas WHERE user_id = ?", (user_id,))
    quota_row = cursor.fetchone()
    storage_limit_mb = quota_row["storage_limit_mb"] if quota_row else 500
    
    cursor.execute("SELECT SUM(size_bytes) as total_used FROM projects WHERE user_id = ? AND is_temp = 0", (user_id,))
    used_row = cursor.fetchone()
    used_bytes = used_row["total_used"] if used_row and used_row["total_used"] else 0
    
    new_size_bytes = len(req.data_json.encode("utf-8"))
    max_bytes = storage_limit_mb * 1024 * 1024
    
    if used_bytes + new_size_bytes > max_bytes:
        conn.close()
        raise HTTPException(
            status_code=400,
            detail=f"Dung lượng dự án vượt quá hạn mức Quota ({storage_limit_mb}MB). Vui lòng dọn dẹp hoặc nâng cấp tài khoản."
        )
        
    project_id = str(uuid.uuid4())
    now = time.time()
    
    cursor.execute("""
    INSERT INTO projects (id, user_id, name, data_json, is_temp, size_bytes, updated_at)
    VALUES (?, ?, ?, ?, 0, ?, ?)
    """, (project_id, user_id, req.name, req.data_json, new_size_bytes, now))
    
    temp_id = f"temp_{user_id}"
    cursor.execute("DELETE FROM projects WHERE id = ? AND is_temp = 1", (temp_id,))
    
    conn.commit()
    conn.close()
    
    return {
        "message": "Đã lưu dự án lên Cloud thành công!",
        "project_id": project_id
    }

@router.get("/cloud")
async def list_cloud_projects(current_user: dict = Depends(get_current_user)):
    user_id = current_user["user_id"]
    conn = get_db_connection()
    cursor = conn.cursor()
    cursor.execute("""
    SELECT id, name, size_bytes, updated_at FROM projects
    WHERE user_id = ? AND is_temp = 0
    ORDER BY updated_at DESC
    """, (user_id,))
    rows = cursor.fetchall()
    conn.close()
    
    return [
        {
            "id": r["id"],
            "name": r["name"],
            "size_mb": round(r["size_bytes"] / (1024 * 1024), 2),
            "updated_at": r["updated_at"]
        } for r in rows
    ]

@router.get("/cloud/{project_id}")
async def get_cloud_project(project_id: str, current_user: dict = Depends(get_current_user)):
    user_id = current_user["user_id"]
    conn = get_db_connection()
    cursor = conn.cursor()
    cursor.execute("SELECT name, data_json FROM projects WHERE id = ? AND user_id = ? AND is_temp = 0", (project_id, user_id))
    row = cursor.fetchone()
    conn.close()
    
    if not row:
        raise HTTPException(status_code=404, detail="Không tìm thấy dự án")
        
    return {
        "id": project_id,
        "name": row["name"],
        "data_json": row["data_json"]
    }

@router.delete("/cloud/{project_id}")
async def delete_cloud_project(project_id: str, current_user: dict = Depends(get_current_user)):
    user_id = current_user["user_id"]
    conn = get_db_connection()
    cursor = conn.cursor()
    cursor.execute("DELETE FROM projects WHERE id = ? AND user_id = ? AND is_temp = 0", (project_id, user_id))
    conn.commit()
    conn.close()
    return {"success": True, "message": "Đã xóa dự án thành công"}

@router.put("/cloud/{project_id}")
async def update_cloud_project(project_id: str, req: SaveProjectRequest, current_user: dict = Depends(get_current_user)):
    user_id = current_user["user_id"]
    conn = get_db_connection()
    cursor = conn.cursor()
    
    cursor.execute("SELECT id FROM projects WHERE id = ? AND user_id = ? AND is_temp = 0", (project_id, user_id))
    exists = cursor.fetchone()
    if not exists:
        conn.close()
        raise HTTPException(status_code=404, detail="Không tìm thấy dự án để cập nhật")
        
    new_size_bytes = len(req.data_json.encode("utf-8"))
    now = time.time()
    
    cursor.execute("""
    UPDATE projects
    SET name = ?, data_json = ?, size_bytes = ?, updated_at = ?
    WHERE id = ? AND user_id = ?
    """, (req.name, req.data_json, new_size_bytes, now, project_id, user_id))
    
    conn.commit()
    conn.close()
    return {"success": True, "message": "Đã cập nhật dự án thành công"}