#!/usr/bin/env python3
"""Shared core logic for Radio Susan DJ — used by radio_dj.py and generate_daily_playlist.py."""

import json
import math
import os
import random
import sqlite3
import time
from pathlib import Path

# ── Paths ──────────────────────────────────────────────────────────────────────
BEETS_DB = "/home/susan/.config/beets/library.db"
NAVIDROME_DB = "/var/lib/navidrome/navidrome.db"
GENRE_CACHE = "/var/lib/radio/genre_cache.json"
FEATURES_DB = "/var/lib/radio/audio_features.db"
STATE_DB = "/var/lib/radio/dj_state.db"
MUSIC_ROOT = "/disks/Plex/Music/"
SUPPORTED = {".flac", ".mp3", ".ogg", ".opus", ".m4a", ".wav"}

# ── Energy curve (hour → target energy 1-10) ──────────────────────────────────
ENERGY_CURVE = {
    0: 1, 1: 1, 2: 1, 3: 1, 4: 1, 5: 1, 6: 1,
    7: 2, 8: 3,
    9: 4, 10: 5, 11: 5,
    12: 4, 13: 4,
    14: 5, 15: 6, 16: 6,
    17: 5, 18: 6,
    19: 7, 20: 8, 21: 7,
    22: 4, 23: 2,
}

# ── Show definitions ───────────────────────────────────────────────────────────
SHOWS = [
    {"name": "Night Drift", "start_hour": 0, "end_hour": 7, "energy": "1", "description": "Ambient, drone, sleep"},
    {"name": "Morning Calm", "start_hour": 7, "end_hour": 9, "energy": "2-3", "description": "Downtempo, chill, acoustic"},
    {"name": "Late Morning", "start_hour": 9, "end_hour": 12, "energy": "4-5", "description": "Indie, jazz, trip-hop"},
    {"name": "Lunch Break", "start_hour": 12, "end_hour": 14, "energy": "4", "description": "Relaxed, soul, dub"},
    {"name": "Afternoon Session", "start_hour": 14, "end_hour": 17, "energy": "5-6", "description": "Electronic, funk, hip-hop"},
    {"name": "Drive Time", "start_hour": 17, "end_hour": 19, "energy": "5-6", "description": "Mixed energy"},
    {"name": "Evening Heat", "start_hour": 19, "end_hour": 22, "energy": "7-8", "description": "Techno, house, DnB, dubstep"},
    {"name": "Wind Down", "start_hour": 22, "end_hour": 24, "energy": "2-4", "description": "Comedown, ambient"},
]

# ── Mode weights ───────────────────────────────────────────────────────────────
MODE_WEIGHTS = {
    "shuffle": 40,
    "deep_cuts": 20,
    "new_to_library": 15,
    "old_favourites": 15,
    "full_album": 10,
}

# ── Cooldowns ──────────────────────────────────────────────────────────────────
TRACK_COOLDOWN = 7 * 86400      # 7 days
ARTIST_COOLDOWN = 3 * 3600      # 3 hours
ALBUM_COOLDOWN = 24 * 3600      # 24 hours

# ── Genre energy keywords (fallback) ──────────────────────────────────────────
ENERGY_KEYWORDS = {
    1: ["ambient", "drone", "new age", "sleep", "meditation"],
    2: ["downtempo", "chill", "lounge", "easy listening", "bossa nova", "minimal"],
    3: ["classical", "chamber", "piano", "acoustic"],
    4: ["jazz", "soul", "trip hop", "lo-fi", "lofi", "dub", "blues"],
    5: ["indie", "pop", "rock", "shoegaze", "post rock", "alternative", "folk", "dream pop"],
    6: ["funk", "disco", "hip hop", "rap", "reggae", "afrobeat"],
    7: ["house", "electronic", "electro", "garage", "dubstep", "idm"],
    8: ["techno", "trance", "drum and bass", "dnb", "jungle", "breakbeat"],
    9: ["industrial", "noise", "hardcore", "metal", "punk"],
    10: ["speedcore", "gabber", "power electronics", "harsh noise"],
}

# ── Station ID variations ─────────────────────────────────────────────────────
STATION_IDS = [
    "Radio Susan, ninety nine point oh.",
    "You're listening to Radio Susan.",
    "Radio Susan.",
    "Susan Radio, always on.",
    "This is Radio Susan.",
]

TTS_VOICES = [
    "en-US-GuyNeural",
    "en-US-ChristopherNeural",
    "en-GB-RyanNeural",
    "en-US-AriaNeural",
    "en-US-JennyNeural",
]


# ── Helpers ────────────────────────────────────────────────────────────────────

def normalize_genre(g):
    return g.lower().replace("-", " ").replace("_", " ").strip() if g else ""


def keyword_energy(genre):
    g = normalize_genre(genre)
    if not g:
        return 5
    for score in range(10, 0, -1):
        for kw in ENERGY_KEYWORDS.get(score, []):
            if kw in g or g in kw:
                return score
    return 5


def essentia_to_scale(e):
    return max(1, min(10, round(e * 9 + 1)))


def open_ro(path):
    if not os.path.exists(path):
        return None
    try:
        c = sqlite3.connect(f"file:{path}?mode=ro", uri=True)
        c.row_factory = sqlite3.Row
        return c
    except Exception:
        return None


def random_file_fallback():
    root = Path(MUSIC_ROOT)
    candidates = [str(p) for p in root.rglob("*") if p.suffix.lower() in SUPPORTED and p.is_file()]
    return random.choice(candidates) if candidates else None


def get_show_for_hour(hour):
    for show in SHOWS:
        if show["start_hour"] <= hour < show["end_hour"]:
            return show
    return SHOWS[0]


# ── Track loading ──────────────────────────────────────────────────────────────

def load_tracks():
    """Load all track metadata. Returns list of dicts with path, artist, album, genre, energy, added, title, duration."""
    tracks = {}

    # Genre cache
    cache = None
    cache_age = float("inf")
    if os.path.exists(GENRE_CACHE):
        try:
            with open(GENRE_CACHE, "r") as f:
                cache = json.load(f)
            cache_age = time.time() - cache.get("built_at", 0)
        except Exception:
            pass

    use_cache = cache is not None and cache_age < 48 * 3600

    # Beets DB
    beets = open_ro(BEETS_DB)
    beets_data = {}
    if beets:
        try:
            for row in beets.execute("SELECT path, title, artist, album, albumartist, genre, added, length FROM items"):
                p = row["path"]
                if isinstance(p, bytes):
                    try:
                        p = p.decode("utf-8")
                    except UnicodeDecodeError:
                        continue
                beets_data[p] = {
                    "title": row["title"] or "",
                    "artist": row["artist"] or row["albumartist"] or "",
                    "album": row["album"] or "",
                    "genre": row["genre"] or "",
                    "added": row["added"] or 0,
                    "duration": row["length"] or 0,
                }
            beets.close()
        except Exception:
            pass

    # Essentia features
    features = {}
    feat_conn = open_ro(FEATURES_DB)
    if feat_conn:
        try:
            for row in feat_conn.execute("SELECT path, energy, bpm FROM features"):
                features[row["path"]] = {"energy": row["energy"], "bpm": row["bpm"]}
            feat_conn.close()
        except Exception:
            pass

    # Merge
    if use_cache:
        for path, info in cache["tracks"].items():
            t = {
                "path": path,
                "artist": info.get("artist", ""),
                "album": info.get("album", ""),
                "title": info.get("title", ""),
                "genre": info.get("genre", "misc"),
                "energy": info.get("energy", 5),
                "added": 0,
                "duration": 240,
            }
            if path in beets_data:
                bd = beets_data[path]
                t["added"] = bd["added"]
                t["duration"] = bd["duration"] if bd["duration"] > 0 else 240
                if not t["artist"]:
                    t["artist"] = bd["artist"]
                if not t["title"]:
                    t["title"] = bd["title"]
            if path in features:
                t["energy"] = essentia_to_scale(features[path]["energy"])
            tracks[path] = t
    elif beets_data:
        for path, bd in beets_data.items():
            energy = keyword_energy(bd["genre"])
            if path in features:
                energy = essentia_to_scale(features[path]["energy"])
            tracks[path] = {
                "path": path,
                "artist": bd["artist"],
                "album": bd["album"],
                "title": bd["title"],
                "genre": normalize_genre(bd["genre"]) or "misc",
                "energy": energy,
                "added": bd["added"],
                "duration": bd["duration"] if bd["duration"] > 0 else 240,
            }
    else:
        root = Path(MUSIC_ROOT)
        for p in root.rglob("*"):
            if p.suffix.lower() in SUPPORTED and p.is_file():
                sp = str(p)
                parts = p.relative_to(MUSIC_ROOT).parts
                artist = parts[0] if len(parts) > 0 else ""
                album = parts[1] if len(parts) > 1 else ""
                energy = 5
                if sp in features:
                    energy = essentia_to_scale(features[sp]["energy"])
                tracks[sp] = {
                    "path": sp, "artist": artist, "album": album,
                    "title": p.stem, "genre": "misc", "energy": energy,
                    "added": 0, "duration": 240,
                }

    return list(tracks.values())


def load_navidrome():
    nav = open_ro(NAVIDROME_DB)
    if not nav:
        return {}
    try:
        data = {}
        rows = nav.execute("""
            SELECT mf.path, a.play_count, a.play_date, a.starred
            FROM media_file mf
            LEFT JOIN annotation a ON a.item_id = mf.id AND a.item_type = 'media_file'
        """).fetchall()
        for r in rows:
            p = r["path"]
            if isinstance(p, bytes):
                try:
                    p = p.decode("utf-8")
                except UnicodeDecodeError:
                    continue
            if not p.startswith("/"):
                p = os.path.join(MUSIC_ROOT, p)
            data[p] = {
                "play_count": r["play_count"] or 0,
                "play_date": r["play_date"] or "",
                "starred": bool(r["starred"]),
            }
        nav.close()
        return data
    except Exception:
        return {}


# ── Selection logic ────────────────────────────────────────────────────────────

def filter_by_energy(tracks, target, tolerance=2):
    pool = [t for t in tracks if abs(t["energy"] - target) <= tolerance]
    while len(pool) < 20 and tolerance < 9:
        tolerance += 1
        pool = [t for t in tracks if abs(t["energy"] - target) <= tolerance]
    return pool


def apply_cooldowns(pool, cooled_paths, cooled_artists, cooled_albums, last_genre):
    result = []
    for t in pool:
        if t["path"] in cooled_paths:
            continue
        if t["artist"] and t["artist"].lower() in cooled_artists:
            continue
        if t["album"] and t["album"].lower() in cooled_albums:
            continue
        if last_genre and normalize_genre(t["genre"]) == last_genre:
            continue
        result.append(t)
    return result


def pick_mode():
    modes = list(MODE_WEIGHTS.keys())
    weights = list(MODE_WEIGHTS.values())
    return random.choices(modes, weights=weights, k=1)[0]


def apply_mode(pool, mode, nav_data, now):
    if mode == "deep_cuts" and nav_data:
        deep = [t for t in pool if nav_data.get(t["path"], {}).get("play_count", 0) == 0]
        if deep:
            return deep, "deep_cuts"

    elif mode == "new_to_library":
        cutoff = now - 2 * 86400
        new = [t for t in pool if t["added"] > cutoff]
        if new:
            return new, "new_to_library"

    elif mode == "old_favourites" and nav_data:
        scored = [(t, nav_data.get(t["path"], {}).get("play_count", 0)) for t in pool]
        scored.sort(key=lambda x: x[1], reverse=True)
        top = [s[0] for s in scored[:max(10, len(scored) // 10)] if s[1] > 0]
        if top:
            return top, "old_favourites"

    return pool, "shuffle"


def contrast_pick(candidates, recent_energies):
    if not recent_energies or len(candidates) <= 1:
        return random.choice(candidates)

    avg_recent = sum(recent_energies) / len(recent_energies)
    scored = [(t, abs(t["energy"] - avg_recent)) for t in candidates]
    scored.sort(key=lambda x: x[1], reverse=True)
    top = scored[:min(3, len(scored))]
    weights = [s[1] + 0.5 for s in top]
    return random.choices([s[0] for s in top], weights=weights, k=1)[0]


def find_album_tracks(pool, min_tracks=3):
    """Group pool by album and return albums with min_tracks+ tracks."""
    albums = {}
    for t in pool:
        if t["album"]:
            key = (t["artist"].lower(), t["album"].lower())
            albums.setdefault(key, []).append(t)
    return {k: sorted(v, key=lambda t: t["path"]) for k, v in albums.items() if len(v) >= min_tracks}