#!/usr/bin/env -S uv run --script
# /// script
# requires-python = ">=3.14"
# dependencies = []
# ///
"""Dump tracks from one or more Spotify playlists (Client Credentials flow).

    just spotify                       # uses the placeholder ids below
    just spotify "<url-or-id> ..."     # explicit playlists
    just spotify "--file lists.txt --json"
    just spotify "<url-or-id> --csv"   # single sockseek CSV (stdout)
    just spotify "<url-or-id> --csv --out tracks.csv"

Playlists can be ids, full URLs, or spotify: URIs. Works for any public
playlist; no user login needed. Requires SPOTIFY_CLIENT_ID /
SPOTIFY_CLIENT_SECRET in the environment (loaded from .env by just).

--csv writes one combined CSV with Artist,Title,Album,Length columns (Length
in seconds), the format consumed by sockseek/sldl. Each playlist is preceded
by a `# <name>` comment line as a separator. Writes to stdout, or to a file
with --out <path>.
"""
import base64
import csv
import json
import os
import re
import sys
import urllib.parse
import urllib.request


def get_token(client_id, client_secret):
    auth = base64.b64encode(f"{client_id}:{client_secret}".encode()).decode()
    data = urllib.parse.urlencode({"grant_type": "client_credentials"}).encode()
    req = urllib.request.Request(
        "https://accounts.spotify.com/api/token",
        data=data,
        headers={"Authorization": f"Basic {auth}"},
    )
    with urllib.request.urlopen(req) as resp:
        return json.load(resp)["access_token"]


def api_get(url, token):
    req = urllib.request.Request(url, headers={"Authorization": f"Bearer {token}"})
    with urllib.request.urlopen(req) as resp:
        return json.load(resp)


def parse_playlist_id(arg):
    m = re.search(r"playlist[/:]([A-Za-z0-9]+)", arg)
    return m.group(1) if m else arg.strip()


def read_list_file(path):
    out = []
    with open(path) as fh:
        for line in fh:
            line = line.split("#", 1)[0].strip()
            if line:
                out.append(line)
    return out


def fetch_playlist(pid, token):
    meta = api_get(
        f"https://api.spotify.com/v1/playlists/{pid}"
        f"?fields={urllib.parse.quote('name,owner(display_name)')}",
        token,
    )
    fields = "items(track(name,artists(name),album(name),duration_ms)),next"
    url = (
        f"https://api.spotify.com/v1/playlists/{pid}/tracks"
        f"?limit=100&fields={urllib.parse.quote(fields)}"
    )
    tracks = []
    while url:
        page = api_get(url, token)
        for item in page.get("items", []):
            t = item.get("track")
            if not t:
                continue
            tracks.append(
                {
                    "title": t["name"],
                    "artists": [a["name"] for a in t["artists"]],
                    "album": t["album"]["name"],
                    "duration_ms": t["duration_ms"],
                }
            )
        url = page.get("next")
    return {"id": pid, "name": meta.get("name"), "tracks": tracks}


def write_csv(playlists, fh):
    """Single combined sockseek/sldl CSV, one `# <name>` comment per playlist."""
    w = csv.writer(fh)
    w.writerow(["Artist", "Title", "Album", "Length"])
    for pl in playlists:
        fh.write(f"# {pl['name']}\n")
        for t in pl["tracks"]:
            w.writerow(
                [
                    ", ".join(t["artists"]),
                    t["title"],
                    t["album"],
                    round(t["duration_ms"] / 1000),
                ]
            )


def main():
    argv = sys.argv[1:]
    as_json = "--json" in argv
    as_csv = "--csv" in argv
    argv = [a for a in argv if a not in ("--json", "--csv")]

    inputs = []
    out_path = None
    i = 0
    while i < len(argv):
        if argv[i] == "--file":
            inputs += read_list_file(argv[i + 1])
            i += 2
        elif argv[i] == "--out":
            out_path = argv[i + 1]
            i += 2
        else:
            inputs.append(argv[i])
            i += 1

    if not inputs:
        sys.exit(
            "usage: spotify.py [--json|--csv] <url-or-id ...> "
            "[--file list.txt] [--out path]"
        )

    client_id = os.environ.get("SPOTIFY_CLIENT_ID")
    client_secret = os.environ.get("SPOTIFY_CLIENT_SECRET")
    if not (client_id and client_secret):
        sys.exit("set SPOTIFY_CLIENT_ID and SPOTIFY_CLIENT_SECRET")

    token = get_token(client_id, client_secret)
    playlists = [fetch_playlist(parse_playlist_id(x), token) for x in inputs]

    if as_json:
        print(json.dumps(playlists, indent=2, ensure_ascii=False))
        return

    if as_csv:
        if out_path:
            with open(out_path, "w", newline="") as fh:
                write_csv(playlists, fh)
            print(f"wrote {sum(len(p['tracks']) for p in playlists)} tracks to {out_path}")
        else:
            write_csv(playlists, sys.stdout)
        return

    for pl in playlists:
        print(f"\n=== {pl['name']} ({len(pl['tracks'])} tracks) ===")
        for n, t in enumerate(pl["tracks"], 1):
            print(f"{n:>3}. {', '.join(t['artists'])} - {t['title']}")


if __name__ == "__main__":
    main()