import hashlib
import os
from datetime import datetime, timezone

import requests
from fastapi import HTTPException
from src.fingering import normalize_fingering_state


def _score_row_to_payload(row: dict) -> dict:
    score_data = row.get("score_data") or {}
    parts = score_data.get("parts") or []
    musicxml_source = score_data.get("musicxml_source") or ""
    fingered_musicxml_source = score_data.get("fingered_musicxml_source") or ""
    fingered_sheet_html = score_data.get("fingered_sheet_html") or ""
    right_hand = parts[0]["notes"] if parts else []
    left_hand = []
    for part in parts[1:]:
        for event in part.get("notes", []):
            pitches = event[0] if isinstance(event[0], list) else [event[0]]
            duration = event[2] if len(event) > 2 else 0.75
            merged = [pitches, event[1], duration]
            if len(event) > 3:
                merged.append(event[3])
            if len(event) > 4:
                if len(merged) == 3:
                    merged.append(None)
                merged.extend(event[4:])
            left_hand.append(merged)
    left_hand.sort(key=lambda event: event[1])
    sheet_html = row.get("sheet_html") or ""
    has_sheet = "<svg" in sheet_html or bool(musicxml_source)
    has_fingered_sheet = "<svg" in fingered_sheet_html or bool(fingered_musicxml_source)
    fingering = normalize_fingering_state(
        parts,
        score_data.get("fingering"),
        has_fingered_sheet=has_fingered_sheet,
    )
    return {
        "name": row.get("slug") or row.get("id"),
        "title": row.get("title") or row.get("slug") or row.get("id"),
        "source_type": row.get("source_type") or "converted",
        "parts": parts,
        "has_sheet": has_sheet,
        "has_fingered_sheet": has_fingered_sheet,
        "measure_beats": row.get("measure_beats") or [],
        "right_hand": right_hand,
        "left_hand": left_hand,
        "sheet_html": sheet_html if has_sheet else "",
        "musicxml_source": musicxml_source,
        "fingered_musicxml_source": fingered_musicxml_source,
        "fingering": fingering,
    }


class SupabaseScoreStore:
    def __init__(self, url: str, service_role_key: str):
        self.base_url = url.rstrip("/")
        self.rest_url = f"{self.base_url}/rest/v1"
        self.headers = {
            "apikey": service_role_key,
            "Authorization": f"Bearer {service_role_key}",
            "Content-Type": "application/json",
        }

    def _request(self, method: str, path: str, *, params=None, json_body=None, headers=None):
        try:
            response = requests.request(
                method,
                f"{self.rest_url}/{path.lstrip('/')}",
                params=params,
                json=json_body,
                headers={**self.headers, **(headers or {})},
                timeout=20,
            )
        except requests.exceptions.Timeout as exc:
            raise HTTPException(status_code=503, detail="Supabase timed out. Try again.") from exc
        except requests.exceptions.RequestException as exc:
            raise HTTPException(status_code=503, detail="Supabase request failed. Try again.") from exc
        if response.status_code >= 400:
            raise HTTPException(status_code=500, detail=f"Supabase error: {response.text}")
        if not response.text:
            return None
        return response.json()

    def list_scores(self, user_id: str):
        rows = self._request(
            "GET",
            "scores",
            params={
                "select": "slug,sheet_html,score_data",
                "user_id": f"eq.{user_id}",
                "order": "created_at.desc",
            },
        ) or []
        names = [row["slug"] for row in rows if row.get("slug")]
        return {
            "scores": names,
            "items": [
                {
                    "name": row["slug"],
                    "has_sheet": "<svg" in (row.get("sheet_html") or "") or bool((row.get("score_data") or {}).get("musicxml_source")),
                }
                for row in rows if row.get("slug")
            ],
        }

    def load_score_row(self, user_id: str, name: str):
        rows = self._request(
            "GET",
            "scores",
            params={
                "select": "id,user_id,slug,title,source_type,score_data,measure_beats,sheet_html,created_at",
                "user_id": f"eq.{user_id}",
                "slug": f"eq.{name}",
                "limit": "1",
            },
        ) or []
        if not rows:
            raise HTTPException(status_code=404, detail=f"Score '{name}' not found")
        return rows[0]

    def load_score(self, user_id: str, name: str):
        return _score_row_to_payload(self.load_score_row(user_id, name))

    def save_score(self, user_id: str, payload: dict):
        existing = self._request(
            "GET",
            "scores",
            params={
                "select": "id,score_data",
                "user_id": f"eq.{user_id}",
                "slug": f"eq.{payload['name']}",
                "limit": "1",
            },
        ) or []
        existing_score_data = (existing[0].get("score_data") or {}) if existing else {}
        row = {
            "user_id": user_id,
            "slug": payload["name"],
            "title": payload.get("title") or payload["name"],
            "source_type": payload.get("source_type") or "converted",
            "score_data": {
                "parts": payload["parts"],
                "musicxml_source": payload.get("musicxml_source") or "",
                "fingered_musicxml_source": payload["fingered_musicxml_source"] if "fingered_musicxml_source" in payload else (existing_score_data.get("fingered_musicxml_source") or ""),
                "fingered_sheet_html": payload["fingered_sheet_html"] if "fingered_sheet_html" in payload else (existing_score_data.get("fingered_sheet_html") or ""),
                "fingering": payload["fingering"] if "fingering" in payload else (existing_score_data.get("fingering") or {}),
            },
            "measure_beats": payload.get("measure_beats") or [],
            "sheet_html": payload.get("sheet_html") or "",
        }
        if existing:
            result = self._request(
                "PATCH",
                "scores",
                params={
                    "user_id": f"eq.{user_id}",
                    "slug": f"eq.{payload['name']}",
                    "select": "id,user_id,slug,title,source_type,score_data,measure_beats,sheet_html,created_at",
                },
                json_body=row,
                headers={"Prefer": "return=representation"},
            ) or []
        else:
            result = self._request(
                "POST",
                "scores",
                params={"select": "id,user_id,slug,title,source_type,score_data,measure_beats,sheet_html,created_at"},
                json_body=row,
                headers={"Prefer": "return=representation"},
            ) or []
        return _score_row_to_payload(result[0]) if result else payload

    def delete_score(self, user_id: str, name: str):
        self._request(
            "DELETE",
            "scores",
            params={
                "user_id": f"eq.{user_id}",
                "slug": f"eq.{name}",
            },
            headers={"Prefer": "return=minimal"},
        )

    def get_app_user_by_username(self, username: str):
        rows = self._request(
            "GET",
            "app_users",
            params={
                "select": "id,username,password_hash,created_at",
                "username": f"eq.{username}",
                "limit": "1",
            },
        ) or []
        return rows[0] if rows else None

    def create_app_user(self, username: str, password_hash: str):
        result = self._request(
            "POST",
            "app_users",
            params={"select": "id,username,password_hash,created_at"},
            json_body={
                "username": username,
                "password_hash": password_hash,
            },
            headers={"Prefer": "return=representation"},
        ) or []
        return result[0] if result else None

    def create_app_session(self, user_id: str, token_hash: str, expires_at_iso: str):
        result = self._request(
            "POST",
            "app_sessions",
            params={"select": "id,user_id,token_hash,expires_at,created_at"},
            json_body={
                "user_id": user_id,
                "token_hash": token_hash,
                "expires_at": expires_at_iso,
            },
            headers={"Prefer": "return=representation"},
        ) or []
        return result[0] if result else None

    def get_app_session_user(self, raw_token: str):
        token_hash = hashlib.sha256(raw_token.encode("utf-8")).hexdigest()
        rows = self._request(
            "GET",
            "app_sessions",
            params={
                "select": "id,user_id,expires_at",
                "token_hash": f"eq.{token_hash}",
                "limit": "1",
            },
        ) or []
        if not rows:
            return None
        session = rows[0]
        expires_at = session.get("expires_at")
        if expires_at:
            expires_dt = datetime.fromisoformat(expires_at.replace("Z", "+00:00"))
            if expires_dt <= datetime.now(timezone.utc):
                self.delete_app_session(raw_token)
                return None
        users = self._request(
            "GET",
            "app_users",
            params={
                "select": "id,username,created_at",
                "id": f"eq.{session['user_id']}",
                "limit": "1",
            },
        ) or []
        if not users:
            return None
        user = users[0]
        user["session_id"] = session.get("id")
        return user

    def delete_app_session(self, raw_token: str):
        token_hash = hashlib.sha256(raw_token.encode("utf-8")).hexdigest()
        self._request(
            "DELETE",
            "app_sessions",
            params={"token_hash": f"eq.{token_hash}"},
            headers={"Prefer": "return=minimal"},
        )


def create_score_store():
    url = os.getenv("SUPABASE_URL", "").strip()
    key = os.getenv("SUPABASE_SERVICE_ROLE_KEY", "").strip()
    if not (url and key):
        raise RuntimeError("SUPABASE_URL and SUPABASE_SERVICE_ROLE_KEY are required.")
    return SupabaseScoreStore(url, key)