import json
from uuid import uuid4

from fastapi import APIRouter, Depends, File, HTTPException, UploadFile
from pydantic import BaseModel

from backend.app.api.dependencies import get_current_user
from backend.app.database import AVATARS_DIR, get_connection, hash_password
from backend.app.services.link_service import create_label, delete_label, list_user_labels, update_label

router = APIRouter()


class UserConfigUpdate(BaseModel):
    email: str | None = None
    bio: str | None = None


class PasswordUpdate(BaseModel):
    current_password: str
    new_password: str


class UserPluginConfigUpdate(BaseModel):
    instance: str | None = None
    access_token: str | None = None
    post_prefix: str | None = None
    hashtag: str | None = None


class LabelUpdate(BaseModel):
    name: str


@router.get('/me')
def get_current_user_profile(user: dict = Depends(get_current_user)):
    with get_connection() as conn:
        row = conn.execute(
            'SELECT * FROM users WHERE id = ?',
            (user['id'],),
        ).fetchone()
    if row is None:
        raise HTTPException(status_code=404, detail='User not found')
    return dict(row)


@router.put('/me')
def update_current_user_profile(
    payload: UserConfigUpdate,
    user: dict = Depends(get_current_user),
):
    with get_connection() as conn:
        current = conn.execute('SELECT * FROM users WHERE id = ?', (user['id'],)).fetchone()
        if current is None:
            raise HTTPException(status_code=404, detail='User not found')

        email = payload.email or current['email']
        bio = payload.bio if payload.bio is not None else current['bio']

        conn.execute(
            '''
            UPDATE users
            SET email = ?, bio = ?, updated_at = CURRENT_TIMESTAMP
            WHERE id = ?
            ''',
            (email, bio, user['id']),
        )
        conn.commit()

    return {'status': 'updated'}


@router.put('/password')
def update_password(payload: PasswordUpdate, user: dict = Depends(get_current_user)):
    if len(payload.new_password) < 8:
        raise HTTPException(status_code=422, detail='New password must be at least 8 characters')
    if hash_password(payload.current_password) != user['password_hash']:
        raise HTTPException(status_code=400, detail='Current password is incorrect')

    with get_connection() as conn:
        conn.execute(
            'UPDATE users SET password_hash = ?, updated_at = CURRENT_TIMESTAMP WHERE id = ?',
            (hash_password(payload.new_password), user['id']),
        )
        conn.commit()
    return {'status': 'password_updated'}


@router.get('/labels')
def get_labels(user: dict = Depends(get_current_user)):
    return list_user_labels(user['id'])


@router.post('/labels', status_code=201)
def add_label(payload: LabelUpdate, user: dict = Depends(get_current_user)):
    try:
        return create_label(user['id'], payload.name)
    except ValueError as error:
        raise HTTPException(status_code=409, detail=str(error)) from error


@router.put('/labels/{label_id}')
def edit_label(label_id: str, payload: LabelUpdate, user: dict = Depends(get_current_user)):
    try:
        result = update_label(label_id, user['id'], payload.name)
    except ValueError as error:
        raise HTTPException(status_code=409, detail=str(error)) from error
    if result is None:
        raise HTTPException(status_code=404, detail='Label not found or not owned by user')
    return result


@router.delete('/labels/{label_id}')
def remove_label(label_id: str, user: dict = Depends(get_current_user)):
    if not delete_label(label_id, user['id']):
        raise HTTPException(status_code=404, detail='Label not found or not owned by user')
    return {'status': 'deleted', 'id': label_id}


@router.post('/avatar')
async def upload_avatar(
    avatar: UploadFile = File(...),
    user: dict = Depends(get_current_user),
):
    allowed_types = {
        'image/gif': '.gif',
        'image/jpeg': '.jpg',
        'image/png': '.png',
        'image/webp': '.webp',
    }
    suffix = allowed_types.get(avatar.content_type or '')
    if suffix is None:
        raise HTTPException(status_code=415, detail='Avatar must be a PNG, JPEG, GIF, or WebP image')

    contents = await avatar.read(2 * 1024 * 1024 + 1)
    if len(contents) > 2 * 1024 * 1024:
        raise HTTPException(status_code=413, detail='Avatar must be 2 MB or smaller')

    avatar_path = AVATARS_DIR / f'{user["id"]}{suffix}'
    for existing_path in AVATARS_DIR.glob(f'{user["id"]}.*'):
        if existing_path != avatar_path:
            existing_path.unlink(missing_ok=True)
    avatar_path.write_bytes(contents)
    avatar_url = f'/media/{avatar_path.name}'

    with get_connection() as conn:
        conn.execute(
            'UPDATE users SET avatar_url = ?, updated_at = CURRENT_TIMESTAMP WHERE id = ?',
            (avatar_url, user['id']),
        )
        conn.commit()
    return {'avatar_url': avatar_url}


@router.get('/plugins/{plugin_name}')
def get_user_plugin_config(plugin_name: str, user: dict = Depends(get_current_user)):
    with get_connection() as conn:
        row = conn.execute(
            'SELECT * FROM user_plugin_config WHERE user_id = ? AND plugin_name = ?',
            (user['id'], plugin_name),
        ).fetchone()

    if row is None:
        return {}

    config = json.loads(row['config']) if row['config'] else {}
    return config


@router.put('/plugins/{plugin_name}')
def update_user_plugin_config(
    plugin_name: str,
    payload: UserPluginConfigUpdate,
    user: dict = Depends(get_current_user),
):
    with get_connection() as conn:
        current = conn.execute(
            'SELECT * FROM user_plugin_config WHERE user_id = ? AND plugin_name = ?',
            (user['id'], plugin_name),
        ).fetchone()

        current_config = json.loads(current['config']) if current and current['config'] else {}
        updates = payload.model_dump(exclude_none=True)
        merged = {**current_config, **updates}

        if current is None:
            conn.execute(
                '''
                INSERT INTO user_plugin_config (id, user_id, plugin_name, config, created_at, updated_at)
                VALUES (?, ?, ?, ?, CURRENT_TIMESTAMP, CURRENT_TIMESTAMP)
                ''',
                (str(uuid4()), user['id'], plugin_name, json.dumps(merged, ensure_ascii=False)),
            )
        else:
            conn.execute(
                '''
                UPDATE user_plugin_config
                SET config = ?, updated_at = CURRENT_TIMESTAMP
                WHERE user_id = ? AND plugin_name = ?
                ''',
                (json.dumps(merged, ensure_ascii=False), user['id'], plugin_name),
            )

        conn.commit()

    return merged