#! /usr/bin/python3

import subprocess
import time
import logging
import re
import os
import socket
import io
import gnudb

SECOND = 1
MINUTE = 60 * SECOND
HOUR = 60 * MINUTE

def scan(state, device):
    logging.info("Scanning CD to get disc ID")
    p = subprocess.run(
        [
            "cd-discid",
            device,
        ],
        encoding="utf-8",
        capture_output=True,
    )
    discid = p.stdout.strip()
    state["discid"] = discid
    cddb_id = discid.split()[0]

    logging.info("Looking disc up on CDDB")
    email = os.environ.get("EMAIL") # You should really set this variable, tho
    if not email:
        user = "user"
        try:
            user = os.getlogin()
        except OSError:
            pass
        email = "%s@%s" % (user, socket.gethostname())
    db_server = gnudb.Server(email)
    disc = db_server.bestguess(discid)
    if disc:
        # There was a hit! Hooray!
        # We're expected to be automatic here,
        # so just use the first one.
        for k in ("title", "artist", "genre", "year", "tracks"):
            state[k] = disc[k]
    else:
        num_tracks = int(discid.split()[1])
        state["title"] = "Unknown CD - %s" % cddb_id
        state["tracks"] = ["Track %02d" % (i+1) for i in range(num_tracks)]

    logging.info("CD scan complete")


def copy(state, device, directory):
    # cdparanoia reports completion in samples
    # use discid duration to figure out total number of samples
    duration = int(state["discid"].split()[-1]) * SECOND # disc duration in seconds
    total_samples = duration * (75 / SECOND) * 1176 # 75 sectors per second, 1176 samples per sector
    state["total_samples"] = total_samples

    track_num = 1
    for track_name in state["tracks"]:
        logging.info("Ripping track %d of %d", track_num, len(state["tracks"]))
        p = subprocess.Popen(
            [
                "cdparanoia",
                "--stderr-progress",
                "--force-cdrom-device", device,
                "--batch",
                str(track_num),
            ],
            cwd = directory,
            stderr = subprocess.PIPE,
            encoding = "utf-8",
        )

        for line in p.stderr:
            line = line.strip()
            if line.startswith("##: -2"):
                samples = int(line.split()[-1])
                yield samples / total_samples

        track_num += 1


def encode(state, directory):
    track_num = 1
    total_tracks = len(state["tracks"])
    durations = [int(d) for d in state["discid"].split()[2:-1]]
    total_duration = sum(durations)
    encoded_duration = 0
    
    tag_script = io.StringIO()
    tag_script.write("#! /bin/sh\n")
    tag_script.write("\n")
    tag_script.write("ALBUM=%s\n" % state["title"])
    tag_script.write("ARTIST=%s\n" % state.get("artist", ""))
    tag_script.write("GENRE=%s\n" % state.get("genre", ""))
    tag_script.write("YEAR=%s\n" % state.get("year", ""))
    tag_script.write("\n")
    
    for track_name in state["tracks"]:
        logging.info("Encoding track %d (%s)" % (track_num, track_name))
        duration = durations[track_num-1]
        argv = [
            "lame",
            "--brief",
            "--nohist",
            "--disptime", "1",
            "--preset", "standard",
            "--tl", state["title"],
            "--tn", "%d/%d" % (track_num, total_tracks),
        ]
        tag_script.write("id3v2")
        tag_script.write(" --album \"$ALBUM\"")
        tag_script.write(" --artist \"$ARTIST\"")
        tag_script.write(" --genre \"$GENRE\"")
        tag_script.write(" --year \"$YEAR\"")
        if state.get("artist"):
            argv.extend(["--ta", state["artist"]])
        if state.get("genre"):
            argv.extend(["--tg", state["genre"]])
        if state.get("year"):
            argv.extend(["--ty", state["year"]])
        if track_name:
            argv.extend(["--tt", track_name])
            tag_script.write(" --song \"%s\"" % track_name)
            outfn = "%02d - %s.mp3" % (track_num, track_name)
        else:
            outfn = "%02d.mp3" % track_num
        argv.append("track%02d.cdda.wav" % track_num)
        argv.append(outfn)
        tag_script.write("\\\n    ")
        tag_script.write(" --track %d/%d" % (track_num, total_tracks))
        tag_script.write(" \"%s\"\n" % outfn)

        p = subprocess.Popen(
            argv,
            cwd = directory,
            stderr = subprocess.PIPE,
            encoding = "utf-8",
        )
        for line in p.stderr:
            line = line.strip()
            if "%)" in line:
                p = line.split("(")[1]
                p = p.split("%")[0]
                pct = int(p) / 100
                yield (encoded_duration + (duration * pct)) / total_duration

        encoded_duration += duration
        track_num += 1

    with open(os.path.join(directory, "tag.sh"), "w") as f:
        f.write(tag_script.getvalue())        


def clean(state, directory):
    for fn in os.listdir(directory):
        if fn.endswith(".wav"):
            os.remove(os.path.join(directory, fn))

if __name__ == "__main__":
    import pprint
    import sys
    import json

    logging.basicConfig(level=logging.DEBUG)

    state = {}
    scan(state, "/dev/sr0")
    pprint.pprint(state)

    directory = os.path.join(".", state["title"])
    os.makedirs(directory, exist_ok=True)
    with open(os.path.join(directory, "state.json"), "w") as f:
        json.dump(f, state)

    for pct in copy(state, "/dev/sr0", directory):
        sys.stdout.write("Copying: %3d%%\r" % (pct*100))
    pprint.pprint(state)

    for pct in encode(state, directory):
        sys.stdout.write("Encoding: %3d%%\r" % (pct*100))
    pprint.pprint(state)

# vi: sw=4 ts=4 et ai