import mido
from .midi_utils import has_musical_messages

CC_NAMES = {
    0: "Bank Select", 1: "Modulation", 2: "Breath Controller", 4: "Foot Controller",
    5: "Portamento Time", 7: "Volume", 10: "Pan", 11: "Expression",
    64: "Sustain Pedal", 65: "Portamento", 66: "Sostenuto", 67: "Soft Pedal",
    71: "Resonance", 72: "Release Time", 73: "Attack Time", 74: "Cutoff Frequency",
    91: "Reverb", 93: "Chorus", 94: "Detune",
}


def get_track_detail(midi: mido.MidiFile, track_index: int) -> dict | None:
    """Extract detailed time-series data for a specific musical track."""
    musical_idx = 0
    target_track = None
    for track in midi.tracks:
        if not has_musical_messages(track):
            continue
        if musical_idx == track_index:
            target_track = track
            break
        musical_idx += 1

    if target_track is None:
        return None

    ticks_per_beat = midi.ticks_per_beat

    track_name = f"Track {track_index + 1}"
    control_changes = {}  # cc_number -> list of [tick, value]
    pitch_bend = []       # list of [tick, value]
    velocities = []       # list of [tick, velocity]
    ongoing_notes = {}    # (note, channel) -> (start_tick, velocity)
    notes = []            # list of [note, start, end, velocity]

    absolute_tick = 0

    for msg in target_track:
        absolute_tick += msg.time

        if msg.type == 'track_name':
            track_name = msg.name
        elif msg.type == 'note_on' and msg.velocity > 0:
            velocities.append([absolute_tick, msg.velocity])
            key = (msg.note, msg.channel)
            ongoing_notes[key] = (absolute_tick, msg.velocity)
        elif msg.type == 'note_off' or (msg.type == 'note_on' and msg.velocity == 0):
            key = (msg.note, msg.channel)
            if key in ongoing_notes:
                start_tick, vel = ongoing_notes.pop(key)
                notes.append([msg.note, start_tick, absolute_tick, vel])
        elif msg.type == 'control_change':
            cc = msg.control
            if cc not in control_changes:
                control_changes[cc] = {
                    "name": CC_NAMES.get(cc, f"CC {cc}"),
                    "data": []
                }
            control_changes[cc]["data"].append([absolute_tick, msg.value])
        elif msg.type == 'pitchwheel':
            pitch_bend.append([absolute_tick, msg.pitch])

    # Convert cc keys to strings for JSON
    cc_out = {}
    for cc_num, cc_data in sorted(control_changes.items()):
        cc_out[str(cc_num)] = cc_data

    total_ticks = absolute_tick

    return {
        "track_name": track_name,
        "ticks_per_beat": ticks_per_beat,
        "total_ticks": total_ticks,
        "notes": notes,
        "control_changes": cc_out,
        "pitch_bend": pitch_bend,
        "velocities": velocities
    }