"""SparkyUI Model Manager - FastAPI app, API routes, and static UI."""
from __future__ import annotations

import asyncio
import os
from pathlib import Path
from typing import Optional

from fastapi import FastAPI, HTTPException
from fastapi.responses import FileResponse
from fastapi.staticfiles import StaticFiles
from pydantic import BaseModel

from . import db, downloader, registries
from .config import (
    KEY_BY_FOLDER,
    MODEL_TYPES,
    MODELS_DIR,
    TYPE_BY_KEY,
    ensure_dirs,
)

STATIC_DIR = Path(__file__).parent / "static"

app = FastAPI(title="SparkyUI Model Manager")


@app.on_event("startup")
def _startup() -> None:
    ensure_dirs()
    db.init_db()
    # Any download left mid-flight by a restart is no longer running.
    for d in db.list_downloads():
        if d["status"] in ("queued", "downloading"):
            db.update_download(d["id"], status="failed",
                               error="Interrupted by restart")


# ---- request models -------------------------------------------------------

class SettingsIn(BaseModel):
    civitai_api_key: Optional[str] = None
    huggingface_token: Optional[str] = None


class DownloadIn(BaseModel):
    url: str
    model_type: Optional[str] = None
    filename: Optional[str] = None


# ---- model types & installed models ---------------------------------------

@app.get("/api/model-types")
def model_types() -> list[dict]:
    return MODEL_TYPES


@app.get("/api/models")
def list_models() -> list[dict]:
    results: list[dict] = []
    for folder, type_key in KEY_BY_FOLDER.items():
        base = MODELS_DIR / folder
        if not base.is_dir():
            continue
        for entry in sorted(base.iterdir()):
            if entry.name.startswith(".") or entry.name.endswith(".part"):
                continue
            if not entry.is_file():
                continue
            stat = entry.stat()
            results.append({
                "name": entry.name,
                "type": type_key,
                "type_label": TYPE_BY_KEY[type_key]["label"],
                "folder": folder,
                "size": stat.st_size,
                "mtime": stat.st_mtime,
            })
    return results


class DeleteModelIn(BaseModel):
    folder: str
    name: str


@app.delete("/api/models")
def delete_model(body: DeleteModelIn) -> dict:
    if body.folder not in KEY_BY_FOLDER:
        raise HTTPException(400, "Unknown model folder")
    name = os.path.basename(body.name)
    base = (MODELS_DIR / body.folder).resolve()
    target = (base / name).resolve()
    if not str(target).startswith(str(base) + os.sep):
        raise HTTPException(400, "Invalid path")
    if not target.is_file():
        raise HTTPException(404, "File not found")
    target.unlink()
    return {"deleted": name}


# ---- settings -------------------------------------------------------------

@app.get("/api/settings")
def get_settings() -> dict:
    # Never return the secrets themselves, only whether they are configured.
    return {
        "civitai_api_key_set": bool(db.get_setting("civitai_api_key")),
        "huggingface_token_set": bool(db.get_setting("huggingface_token")),
    }


@app.post("/api/settings")
def save_settings(body: SettingsIn) -> dict:
    # `None` leaves a value untouched; empty string clears it.
    if body.civitai_api_key is not None:
        db.set_setting("civitai_api_key", body.civitai_api_key)
    if body.huggingface_token is not None:
        db.set_setting("huggingface_token", body.huggingface_token)
    return get_settings()


# ---- downloads ------------------------------------------------------------

@app.get("/api/downloads")
def get_downloads() -> list[dict]:
    return db.list_downloads()


@app.post("/api/downloads")
async def start_download(body: DownloadIn) -> dict:
    url = body.url.strip()
    if not url:
        raise HTTPException(400, "URL is required")

    try:
        resolved = await registries.resolve(url)
    except Exception as exc:  # noqa: BLE001 - report resolution failure to the user
        raise HTTPException(400, f"Could not resolve URL: {exc}")

    # Pick the model type: explicit user choice wins, else registry suggestion.
    model_type = body.model_type or resolved.model_type
    if not model_type:
        raise HTTPException(
            400, "Please choose a model type for this download.")
    if model_type not in TYPE_BY_KEY:
        raise HTTPException(400, "Unknown model type")

    filename = body.filename or resolved.filename or ""

    download_id = db.create_download(
        url=resolved.download_url,
        source=resolved.source,
        model_type=model_type,
        filename=filename,
        dest_path="",
    )

    asyncio.create_task(downloader.run_download(
        download_id=download_id,
        url=resolved.download_url,
        headers=resolved.headers,
        model_type=model_type,
        filename=filename or None,
    ))

    row = db.get_download(download_id)
    return row or {"id": download_id}


@app.delete("/api/downloads/{download_id}")
def delete_download(download_id: int) -> dict:
    row = db.get_download(download_id)
    if not row:
        raise HTTPException(404, "Download not found")
    # If it's running, signal cancel; the task will mark it canceled.
    if downloader.request_cancel(download_id):
        return {"canceled": download_id}
    db.delete_download(download_id)
    return {"removed": download_id}


# ---- static UI ------------------------------------------------------------

@app.get("/")
def index() -> FileResponse:
    return FileResponse(STATIC_DIR / "index.html")


app.mount("/", StaticFiles(directory=str(STATIC_DIR)), name="static")