from pathlib import Path

from fastapi import APIRouter, Depends, File, HTTPException, UploadFile
from fastapi.responses import FileResponse
from sqlalchemy.orm import Session

from app.auth import require_admin
from app.database import get_db
from app.models import User
from app.schemas import SystemSettingsOut, SystemSettingsUpdate
from app.system_settings import (
    clear_logo_files,
    ensure_upload_dir,
    find_logo_file,
    get_or_create_settings,
    logo_path,
    public_logo_url,
)

router = APIRouter(prefix="/api", tags=["settings"])

ALLOWED_LOGO_EXT = {".png", ".jpg", ".jpeg", ".webp", ".svg", ".gif"}
MAX_LOGO_BYTES = 2 * 1024 * 1024


def _settings_out(db: Session) -> SystemSettingsOut:
    row = get_or_create_settings(db)
    return SystemSettingsOut(system_name=row.system_name, logo_url=public_logo_url(row.logo_ext or None))


@router.get("/settings", response_model=SystemSettingsOut)
def get_settings(db: Session = Depends(get_db)):
    return _settings_out(db)


@router.get("/settings/logo")
def get_logo(db: Session = Depends(get_db)):
    row = get_or_create_settings(db)
    path = find_logo_file(row.logo_ext or None)
    if not path:
        raise HTTPException(404, detail="未设置 Logo")
    media = {
        ".png": "image/png",
        ".jpg": "image/jpeg",
        ".jpeg": "image/jpeg",
        ".webp": "image/webp",
        ".svg": "image/svg+xml",
        ".gif": "image/gif",
    }.get(path.suffix.lower(), "application/octet-stream")
    return FileResponse(path, media_type=media)


@router.put("/admin/settings", response_model=SystemSettingsOut)
def update_settings(
    body: SystemSettingsUpdate,
    db: Session = Depends(get_db),
    _: User = Depends(require_admin),
):
    row = get_or_create_settings(db)
    row.system_name = body.system_name.strip()
    db.commit()
    db.refresh(row)
    return _settings_out(db)


@router.post("/admin/settings/logo", response_model=SystemSettingsOut)
async def upload_logo(
    file: UploadFile = File(...),
    db: Session = Depends(get_db),
    _: User = Depends(require_admin),
):
    if not file.filename:
        raise HTTPException(400, detail="请选择文件")
    ext = Path(file.filename).suffix.lower()
    if ext not in ALLOWED_LOGO_EXT:
        raise HTTPException(400, detail="仅支持 png、jpg、webp、svg、gif")
    content = await file.read()
    if len(content) > MAX_LOGO_BYTES:
        raise HTTPException(400, detail="Logo 不能超过 2MB")
    ensure_upload_dir()
    clear_logo_files()
    ext_clean = ext.lstrip(".")
    dest = logo_path(ext_clean)
    dest.write_bytes(content)
    row = get_or_create_settings(db)
    row.logo_ext = ext_clean
    db.commit()
    db.refresh(row)
    return _settings_out(db)


@router.delete("/admin/settings/logo", response_model=SystemSettingsOut)
def delete_logo(
    db: Session = Depends(get_db),
    _: User = Depends(require_admin),
):
    clear_logo_files()
    row = get_or_create_settings(db)
    row.logo_ext = ""
    db.commit()
    db.refresh(row)
    return _settings_out(db)