"""FlowDeck — Calendar links + Meetings API (v7.1.0).

``/api/v2/calendar-links*`` — Google/CalDAV link CRUD (session or Bearer
``write``), manual sync trigger. ``GET /db/{id}/calendar/freebusy`` —
weekday availability. ``/api/v2/meetings/*`` — audio upload, manual
transcript, AI summary (fires ``meeting.summarized``).

See ``docs/V71_Calendar_Meetings.md``.
"""
from __future__ import annotations

import secrets

from fastapi import APIRouter, Body, HTTPException, Request
from fastapi.responses import JSONResponse

from app.auth.session import SessionManager
from app.db import get_conn
from app.services import calendar_sync as cal
from app.services import meetings as meet
from app.services.api_v2_helpers import (
    audit_log,
    has_scope,
    resolve_bearer_token,
    row_to_dict,
)

router = APIRouter(tags=["calendar-meetings"])


def _auth_user(request: Request, *, require_write: bool = False) -> dict:
    sess = SessionManager.decode_session(request.cookies.get("flowdeck_session", ""))
    if sess:
        return sess
    auth = request.headers.get("authorization") or request.headers.get("Authorization") or ""
    if auth.lower().startswith("bearer "):
        user = resolve_bearer_token(auth[7:].strip())
        if not user:
            raise HTTPException(401, "Invalid or expired API token")
        if require_write and not has_scope(user.get("_token_scopes") or "read", "write"):
            raise HTTPException(403, "Insufficient scope. Required: write")
        return user
    raise HTTPException(401, "Authentication required")


# ── calendar links ─────────────────────────────────────────────────────────

@router.post("/api/v2/calendar-links")
def create_link(request: Request, body: dict = Body(default={})):
    user = _auth_user(request, require_write=True)
    provider = (body.get("provider") or "").lower()
    if provider not in cal.PROVIDERS:
        raise HTTPException(400, "provider must be google|caldav")
    try:
        collection_id = int(body.get("collection_id", 0))
    except (TypeError, ValueError):
        raise HTTPException(400, "collection_id required") from None
    creds = body.get("credentials") or {}
    if provider == "google" and not creds.get("access_token"):
        raise HTTPException(400, "google needs credentials.access_token")
    if provider == "caldav" and not creds.get("url"):
        raise HTTPException(400, "caldav needs credentials.url")
    try:
        out = cal.save_link(user["id"], provider, collection_id, creds,
                            body.get("calendar_id") or "primary",
                            body.get("date_property") or "")
    except ValueError as exc:
        raise HTTPException(400, str(exc)) from None
    audit_log(user, "calendar.link", "collection", collection_id, provider, request)
    return JSONResponse(status_code=201, content=out)


@router.get("/api/v2/calendar-links")
def get_links(request: Request):
    user = _auth_user(request)
    return {"links": cal.list_links(user["id"])}


@router.delete("/api/v2/calendar-links/{link_id}")
def remove_link(link_id: int, request: Request):
    user = _auth_user(request, require_write=True)
    if not cal.delete_link(user["id"], link_id):
        raise HTTPException(404, "Link not found")
    audit_log(user, "calendar.unlink", "calendar_link", link_id, "", request)
    return {"status": "deleted", "id": link_id}


@router.post("/api/v2/calendar-links/{link_id}/sync")
async def sync_now(link_id: int, request: Request):
    user = _auth_user(request, require_write=True)
    with get_conn() as conn:
        row = conn.execute("SELECT * FROM calendar_links WHERE id=?", (link_id,)).fetchone()
    if not row or (row["user_id"] != user["id"] and not user.get("is_admin")):
        raise HTTPException(404, "Link not found")
    try:
        stats = await cal.sync_link(link_id)
    except (cal.SyncError, ValueError) as exc:
        raise HTTPException(502 if isinstance(exc, cal.SyncError) else 400,
                            str(exc)) from None
    audit_log(user, "calendar.sync", "calendar_link", link_id, str(stats), request)
    return {"link_id": link_id, **stats}


# ── free/busy ──────────────────────────────────────────────────────────────

@router.get("/db/{collection_id}/calendar/freebusy")
def freebusy(collection_id: int, request: Request):
    _auth_user(request)
    qp = request.query_params
    try:
        out = cal.freebusy(collection_id, qp.get("from", ""), qp.get("to", ""),
                           qp.get("date_property", ""))
    except ValueError as exc:
        raise HTTPException(400, str(exc)) from None
    return out


# ── meetings ───────────────────────────────────────────────────────────────

@router.post("/api/v2/meetings/transcribe")
async def upload_and_transcribe(request: Request):
    user = _auth_user(request, require_write=True)
    try:
        form = await request.form()
    except Exception:
        raise HTTPException(400, "multipart upload required") from None
    upload = form.get("audio")
    try:
        page_id = int(form.get("page_id", 0))
    except (TypeError, ValueError):
        raise HTTPException(400, "page_id required") from None
    language = (form.get("language") or "fr")[:10]
    manual = (form.get("transcript") or "").strip()
    if upload is None and not manual:
        raise HTTPException(400, "audio file or transcript required")
    audio_path = ""
    if upload is not None:
        filename = (upload.filename or "").lower()
        ext = filename.rsplit(".", 1)[-1] if "." in filename else ""
        if ext not in meet.AUDIO_EXTENSIONS:
            raise HTTPException(400, f"audio must be one of {sorted(meet.AUDIO_EXTENSIONS)}")
        data = await upload.read()
        if len(data) > meet.MAX_AUDIO_BYTES:
            raise HTTPException(413, "audio exceeds 100 MB")
        if not data:
            raise HTTPException(400, "empty audio file")
        audio_path = str(meet.meetings_dir()
                         / f"{page_id}_{secrets.token_hex(8)}.{ext}")
        with open(audio_path, "wb") as fh:
            fh.write(data)
    transcript = manual
    if not transcript and audio_path:
        try:
            transcript = meet.transcribe_audio(audio_path, language)
        except meet.TranscriptionUnavailable as exc:
            transcript = ""  # stored; client transcribes or posts manual text later
            _ = exc
    try:
        tid = meet.save_transcript(page_id, transcript, language, audio_path)
    except ValueError as exc:
        raise HTTPException(404, str(exc)) from None
    with get_conn() as conn:
        row = conn.execute("SELECT * FROM meeting_transcripts WHERE id=?", (tid,)).fetchone()
    audit_log(user, "meeting.transcribe", "page", page_id, f"transcript={tid}", request)
    return JSONResponse(status_code=201, content={
        **row_to_dict(row), "transcribed": bool(transcript)})


@router.post("/api/v2/meetings/transcripts/{transcript_id}/text")
def set_transcript_text(transcript_id: int, request: Request, body: dict = Body(default={})):
    """Store a client-side (manual) transcript on an existing row."""
    _auth_user(request, require_write=True)
    text = (body.get("transcript") or "").strip()
    if not text:
        raise HTTPException(400, "transcript required")
    with get_conn() as conn:
        if not conn.execute("SELECT id FROM meeting_transcripts WHERE id=?",
                            (transcript_id,)).fetchone():
            raise HTTPException(404, "Transcript not found")
        conn.execute("UPDATE meeting_transcripts SET transcript=? WHERE id=?",
                     (text, transcript_id))
        conn.commit()
        row = conn.execute("SELECT * FROM meeting_transcripts WHERE id=?",
                           (transcript_id,)).fetchone()
    return row_to_dict(row)


@router.post("/api/v2/meetings/transcripts/{transcript_id}/summarize")
async def summarize(transcript_id: int, request: Request):
    user = _auth_user(request, require_write=True)
    try:
        out = await meet.summarize_transcript(transcript_id, user.get("id"))
    except ValueError as exc:
        raise HTTPException(400, str(exc)) from None
    except RuntimeError as exc:
        raise HTTPException(502, str(exc)) from None
    audit_log(user, "meeting.summarize", "transcript", transcript_id, "", request)
    return out