# -*- coding: utf-8 -*-
"""
API-Client für Desktop-Anwendungen.

Stellt alle Backend-Aufrufe als einfache Funktionen bereit.
Hybrid-Modus: versucht Backend, fällt auf lokalen OpenAI-Call zurück.

    from workforce_planner.api_client import WorkforceClient
    client = WorkforceClient("http://localhost:8000")
    client.login("admin@praxis.ch", "admin123")
    result = client.transcribe_audio("recording.wav")
"""

import os
import threading
from typing import Optional, Callable

import requests
from requests.exceptions import ConnectionError, Timeout, RequestException


_BACKEND_TIMEOUT_TRANSCRIBE = 20
_BACKEND_TIMEOUT_DEFAULT = 12


class WorkforceClient:
    """HTTP-Client für das workforce_planner Backend."""

    def __init__(self, base_url: str = "http://localhost:8000"):
        self.base_url = base_url.rstrip("/")
        self.token: Optional[str] = None
        self.employee: Optional[dict] = None
        self._session = requests.Session()

    @property
    def _headers(self) -> dict:
        h = {}
        if self.token:
            h["Authorization"] = f"Bearer {self.token}"
        return h

    @property
    def is_authenticated(self) -> bool:
        return self.token is not None

    def is_backend_available(self) -> bool:
        try:
            r = self._session.get(
                f"{self.base_url}/api/v1/health", timeout=3
            )
            return r.status_code == 200
        except RequestException:
            return False

    # ─── Auth ───────────────────────────────────

    def login(self, email: str, password: str) -> dict:
        r = self._session.post(
            f"{self.base_url}/api/v1/auth/login",
            json={"email": email, "password": password},
            timeout=_BACKEND_TIMEOUT_DEFAULT,
        )
        r.raise_for_status()
        data = r.json()
        self.token = data["access_token"]
        self.employee = data["employee"]
        return data

    def logout(self):
        self.token = None
        self.employee = None

    # ─── Employees ──────────────────────────────

    def list_employees(self, active_only: bool = True) -> list[dict]:
        r = self._session.get(
            f"{self.base_url}/api/v1/employees/",
            headers=self._headers,
            params={"active_only": active_only},
            timeout=_BACKEND_TIMEOUT_DEFAULT,
        )
        r.raise_for_status()
        return r.json()

    def create_employee(self, data: dict) -> dict:
        r = self._session.post(
            f"{self.base_url}/api/v1/employees/",
            headers=self._headers,
            json=data,
            timeout=_BACKEND_TIMEOUT_DEFAULT,
        )
        r.raise_for_status()
        return r.json()

    def update_employee(self, employee_id: str, data: dict) -> dict:
        r = self._session.patch(
            f"{self.base_url}/api/v1/employees/{employee_id}",
            headers=self._headers,
            json=data,
            timeout=_BACKEND_TIMEOUT_DEFAULT,
        )
        r.raise_for_status()
        return r.json()

    def delete_employee(self, employee_id: str):
        r = self._session.delete(
            f"{self.base_url}/api/v1/employees/{employee_id}",
            headers=self._headers,
            timeout=_BACKEND_TIMEOUT_DEFAULT,
        )
        r.raise_for_status()

    # ─── Absences ───────────────────────────────

    def list_absences(self, year: Optional[int] = None, employee_id: Optional[str] = None) -> list[dict]:
        params = {}
        if year:
            params["year"] = year
        if employee_id:
            params["employee_id"] = employee_id
        r = self._session.get(
            f"{self.base_url}/api/v1/absences/",
            headers=self._headers,
            params=params,
            timeout=_BACKEND_TIMEOUT_DEFAULT,
        )
        r.raise_for_status()
        return r.json()

    def create_absence(self, data: dict) -> dict:
        r = self._session.post(
            f"{self.base_url}/api/v1/absences/",
            headers=self._headers,
            json=data,
            timeout=_BACKEND_TIMEOUT_DEFAULT,
        )
        if r.status_code == 422:
            detail = r.json().get("detail", {})
            raise ValueError(detail.get("message", str(detail)))
        r.raise_for_status()
        return r.json()

    def delete_absence(self, absence_id: str):
        r = self._session.delete(
            f"{self.base_url}/api/v1/absences/{absence_id}",
            headers=self._headers,
            timeout=_BACKEND_TIMEOUT_DEFAULT,
        )
        r.raise_for_status()

    def get_balance(self, employee_id: str, year: int) -> dict:
        r = self._session.get(
            f"{self.base_url}/api/v1/balance/{employee_id}/{year}",
            headers=self._headers,
            timeout=_BACKEND_TIMEOUT_DEFAULT,
        )
        r.raise_for_status()
        return r.json()

    # ─── KI-Service (Hybrid) ────────────────────

    def transcribe_audio(self, wav_path: str, language: str = "de") -> dict:
        """
        Sendet WAV an Backend. Bei Fehler: wirft Exception
        (Fallback wird vom Caller gehandhabt).
        """
        with open(wav_path, "rb") as f:
            r = self._session.post(
                f"{self.base_url}/api/v1/ai/transcribe",
                headers=self._headers,
                files={"file": (os.path.basename(wav_path), f, "audio/wav")},
                data={"language": language},
                timeout=_BACKEND_TIMEOUT_TRANSCRIBE,
            )
        r.raise_for_status()
        return r.json()

    def summarize(self, transcript: str, system_prompt: str = "", model: str = "gpt-4o") -> dict:
        r = self._session.post(
            f"{self.base_url}/api/v1/ai/summarize",
            headers=self._headers,
            json={"transcript": transcript, "system_prompt": system_prompt, "model": model},
            timeout=30,
        )
        r.raise_for_status()
        return r.json()

    def merge_kg(self, existing_kg: str, full_transcript: str,
                 system_prompt: str = "", model: str = "gpt-4o") -> dict:
        r = self._session.post(
            f"{self.base_url}/api/v1/ai/merge",
            headers=self._headers,
            json={
                "existing_kg": existing_kg,
                "full_transcript": full_transcript,
                "system_prompt": system_prompt,
                "model": model,
            },
            timeout=30,
        )
        r.raise_for_status()
        return r.json()

    def chat(self, messages: list[dict], model: str = "gpt-4o") -> dict:
        r = self._session.post(
            f"{self.base_url}/api/v1/ai/chat",
            headers=self._headers,
            json={"messages": messages, "model": model},
            timeout=30,
        )
        r.raise_for_status()
        return r.json()


# ═══════════════════════════════════════════════════════════
# HYBRID-TRANSKRIPTION: Backend mit lokalem Fallback
# ═══════════════════════════════════════════════════════════

def hybrid_transcribe(
    wav_path: str,
    api_client: Optional[WorkforceClient],
    local_transcribe_fn: Callable[[str], str],
    on_success: Callable[[str, str], None],
    on_error: Optional[Callable[[str], None]] = None,
):
    """
    Hybrid-Transkription: versucht Backend, fällt auf lokal zurück.
    Läuft in eigenem Thread → UI blockiert nie.

    Args:
        wav_path:             Pfad zur WAV-Datei
        api_client:           WorkforceClient (oder None = immer lokal)
        local_transcribe_fn:  Bestehende lokale Transkription (self.transcribe_wav)
        on_success:           Callback(text, source) – source = "backend" oder "local"
        on_error:             Callback(error_message) bei totalem Fehler
    """
    def _worker():
        source = "local"
        text = ""

        # ── Versuch 1: Backend ──
        if api_client and api_client.is_authenticated:
            try:
                result = api_client.transcribe_audio(wav_path)
                text = result.get("text", "")
                source = "backend"
            except (ConnectionError, Timeout):
                pass
            except RequestException:
                pass

        # ── Versuch 2: Lokal (Fallback) ──
        if not text and source == "local":
            try:
                text = local_transcribe_fn(wav_path)
                source = "local"
            except Exception as exc:
                if on_error:
                    on_error(f"Transkription fehlgeschlagen: {exc}")
                return

        on_success(text, source)

    t = threading.Thread(target=_worker, daemon=True)
    t.start()
    return t