#!/usr/bin/env python3
"""Extract one wave out of a `.slb` bank as a standalone XMA1 RIFF.

For banks with no internal delimiters -- `Static.slb`, which is a packed run of
whole 2048-byte XMA packets -- a wave is defined only by (offset, packet count).
Those come from the running game: launch Canary with `--xma_param_probe=true`,
trigger the sound, and the log prints the stream's packet count and first 32
bytes; search those bytes in the bank to get the offset.
See docs/re/menu-audio-cues.md.

    slb_extract_wave.py <bank.slb name> <offset> <packets> [channels] [rate] [out.riff]
    slb_extract_wave.py Static.slb 0x1ec0 4            # the d-pad cursor cue

Decode with:  ffmpeg -i out.riff out.wav
"""
import os, struct, sys
from disc import disc_root
sys.path.insert(0, os.path.dirname(os.path.abspath(__file__)))
exec(open(os.path.join(os.path.dirname(os.path.abspath(__file__)),
                       "slb_segment_phase.py")).read().split("def cmd_phases")[0])

XMA1_PACKET = 2048

def synth_fmt(channels, mask, rate):
    """The 32-byte XMAWAVEFORMAT ffmpeg's `xma1` decoder wants."""
    f  = b"fmt " + struct.pack("<I", 32)
    f += struct.pack("<HHHH", 0x0165, 16, 0, 0)      # tag=XMA1, bits, opts, skip
    f += struct.pack("<H", 1) + bytes([0, 3])        # streams, loopcount, version
    f += struct.pack("<IIII", rate * channels * 2, rate, 0, 0)
    f += bytes([4, channels]) + struct.pack("<H", mask)
    return f

def riff(fmt, data):
    body = b"WAVE" + fmt + b"data" + struct.pack("<I", len(data)) + data
    return b"RIFF" + struct.pack("<I", len(body)) + body

def main():
    a = sys.argv[1:]
    if len(a) < 3:
        print(__doc__); return 1
    name, off, pkts = a[0], int(a[1], 0), int(a[2], 0)
    ch   = int(a[3]) if len(a) > 3 else 1
    rate = int(a[4]) if len(a) > 4 else 48000
    out  = a[5] if len(a) > 5 else f"{name.split('.')[0]}_{off:#x}.riff"
    disc = disc_root()
    pak  = Pak(os.path.join(disc, "dat", "sound.pak"))
    i    = pak.find(name)
    if i is None:
        print(f"{name}: not in sound.pak"); return 2
    b    = pak.read(i)
    data = b[off:off + pkts * XMA1_PACKET]
    if len(data) < pkts * XMA1_PACKET:
        print(f"warning: short read -- {len(data)} of {pkts * XMA1_PACKET} bytes")
    open(out, "wb").write(riff(synth_fmt(ch, 1 if ch == 1 else 2, rate), data))
    print(f"{out}: {len(data)} bytes, {pkts} packets, {ch}ch {rate}Hz")
    return 0

if __name__ == "__main__":
    raise SystemExit(main())