from __future__ import annotations

from pathlib import Path
import threading

from fastapi import FastAPI, HTTPException
from fastapi.responses import FileResponse, JSONResponse
from fastapi.staticfiles import StaticFiles

from app.config import get_settings
from app.docker_api import DockerApiClient, DockerApiError, DockerUsageResolver
from app.dns_sync import DnsSyncError, build_dns_provider
from app.ip_commands import CommandError, IpAddressManager
from app.service import (
    ConflictError,
    DependencyError,
    EntryService,
    NotFoundError,
    ValidationError,
)
from app.storage import EntryStorage


def build_service() -> EntryService:
    settings = get_settings()
    storage = EntryStorage(settings.state_file)
    docker_client = DockerApiClient(settings.docker_api_url, timeout_seconds=settings.docker_timeout_seconds)
    usage_resolver = DockerUsageResolver(docker_client)
    ip_manager = IpAddressManager()
    dns_provider = build_dns_provider(
        settings.dns_provider,
        adguard_url=settings.adguard_url,
        adguard_username=settings.adguard_username,
        adguard_password=settings.adguard_password,
        rfc2136_server=settings.rfc2136_server,
        rfc2136_zone=settings.rfc2136_zone,
        rfc2136_port=settings.rfc2136_port,
        rfc2136_tsig_key_name=settings.rfc2136_tsig_key_name,
        rfc2136_tsig_secret=settings.rfc2136_tsig_secret,
        rfc2136_tsig_algorithm=settings.rfc2136_tsig_algorithm,
        timeout_seconds=settings.docker_timeout_seconds,
    )
    return EntryService(
        storage=storage,
        usage_resolver=usage_resolver,
        ip_manager=ip_manager,
        dns_provider=dns_provider,
        dns_base_domain=settings.dns_base_domain,
        dns_ttl_seconds=settings.dns_ttl_seconds,
    )


service = build_service()
app = FastAPI(title="Docker IP Addr Manager", version="0.1.0")
settings = get_settings()
stop_event = threading.Event()
background_thread: threading.Thread | None = None

static_dir = Path(__file__).parent / "static"
app.mount("/static", StaticFiles(directory=static_dir), name="static")


@app.on_event("startup")
def startup_reconcile() -> None:
    errors = service.reconcile_enabled_entries()
    if errors:
        for error in errors:
            print(f"[startup-reconcile] {error}")
    dns_errors = service.reconcile_dns_records()
    if dns_errors:
        for error in dns_errors:
            print(f"[dns-reconcile-startup] {error}")
    _start_dns_background_loop()


@app.on_event("shutdown")
def shutdown_reconcile() -> None:
    stop_event.set()
    if background_thread and background_thread.is_alive():
        background_thread.join(timeout=2.0)


def _dns_background_worker(interval_seconds: float) -> None:
    while not stop_event.wait(interval_seconds):
        errors = service.reconcile_dns_records()
        for error in errors:
            print(f"[dns-reconcile] {error}")


def _start_dns_background_loop() -> None:
    global background_thread
    if settings.dns_provider.strip().lower() in {"", "none"}:
        return
    if background_thread and background_thread.is_alive():
        return
    background_thread = threading.Thread(
        target=_dns_background_worker,
        args=(max(settings.dns_sync_interval_seconds, 1.0),),
        daemon=True,
    )
    background_thread.start()


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


@app.get("/healthz")
def healthz() -> dict:
    return {"ok": True}


@app.get("/api/interfaces")
def list_interfaces() -> dict:
    try:
        return {"items": service.list_interfaces()}
    except DependencyError as exc:
        raise HTTPException(status_code=503, detail=str(exc)) from exc


@app.get("/api/entries")
def list_entries() -> dict:
    response = service.list_entries()
    return response.to_dict()


@app.post("/api/refresh")
def refresh_entries() -> dict:
    response = service.list_entries()
    return response.to_dict()


@app.post("/api/entries")
def create_entry(payload: dict) -> dict:
    try:
        entry = service.create_entry(payload)
        return entry.to_dict()
    except ValidationError as exc:
        raise HTTPException(status_code=422, detail=str(exc)) from exc
    except ConflictError as exc:
        raise HTTPException(status_code=409, detail=str(exc)) from exc


@app.put("/api/entries/{entry_id}")
def update_entry(entry_id: str, payload: dict) -> dict:
    try:
        entry = service.update_entry(entry_id, payload)
        return entry.to_dict()
    except ValidationError as exc:
        raise HTTPException(status_code=422, detail=str(exc)) from exc
    except ConflictError as exc:
        raise HTTPException(status_code=409, detail=str(exc)) from exc
    except NotFoundError as exc:
        raise HTTPException(status_code=404, detail=str(exc)) from exc


@app.post("/api/entries/{entry_id}/enable")
def enable_entry(entry_id: str) -> dict:
    try:
        entry = service.set_enabled(entry_id, enabled=True)
        return entry.to_dict()
    except NotFoundError as exc:
        raise HTTPException(status_code=404, detail=str(exc)) from exc
    except (ConflictError, CommandError) as exc:
        raise HTTPException(status_code=409, detail=str(exc)) from exc
    except DependencyError as exc:
        raise HTTPException(status_code=503, detail=str(exc)) from exc


@app.post("/api/entries/{entry_id}/disable")
def disable_entry(entry_id: str) -> dict:
    try:
        entry = service.set_enabled(entry_id, enabled=False)
        return entry.to_dict()
    except NotFoundError as exc:
        raise HTTPException(status_code=404, detail=str(exc)) from exc
    except (ConflictError, CommandError) as exc:
        raise HTTPException(status_code=409, detail=str(exc)) from exc
    except DependencyError as exc:
        raise HTTPException(status_code=503, detail=str(exc)) from exc


@app.delete("/api/entries/{entry_id}")
def delete_entry(entry_id: str) -> dict:
    try:
        service.delete_entry(entry_id)
        return {"deleted": True}
    except NotFoundError as exc:
        raise HTTPException(status_code=404, detail=str(exc)) from exc
    except ConflictError as exc:
        raise HTTPException(status_code=409, detail=str(exc)) from exc
    except DependencyError as exc:
        raise HTTPException(status_code=503, detail=str(exc)) from exc


@app.exception_handler(DockerApiError)
async def docker_error_handler(_, exc: DockerApiError):
    return JSONResponse(status_code=503, content={"detail": str(exc)})


@app.exception_handler(DnsSyncError)
async def dns_error_handler(_, exc: DnsSyncError):
    return JSONResponse(status_code=503, content={"detail": str(exc)})