#!/usr/bin/env python3
"""rtctx_rt.py — P1.5: find live ctx via REAPER realtime transport playback.

Launches REAPER with render_long.rpp + play.lua (realtime audio playback, host
audio callback alive), then snapshots the yabridge-host memory during playback
and searches for the DSP ctx by FUN_180535ae0 constructor markers.

Usage: rtctx_rt.py
"""
import subprocess, os, glob, time, struct, sys, json

SNAP = '/tmp/snap_rt.bin'


def mem_open(pid):
    return os.open(f'/proc/{pid}/mem', os.O_RDONLY)


def find_host():
    for p in glob.glob('/proc/[0-9]*'):
        pid = int(os.path.basename(p))
        try:
            cmd = open(f'/proc/{pid}/cmdline', 'rb').read().replace(b'\0', b' ').decode('utf8', 'replace')
            maps = open(f'/proc/{pid}/maps').read()
        except Exception:
            continue
        if 'soothe2' in maps and 'reaper' not in cmd:
            return pid
    return None


def snapshot(host):
    fd = mem_open(host)
    out = open(SNAP, 'wb')
    nreg = 0; nbytes = 0; t0 = time.time()
    for line in open(f'/proc/{host}/maps').read().splitlines():
        p = line.split()
        if len(p) < 2: continue
        lo, hi = (int(x, 16) for x in p[0].split('-'))
        if 'r' not in p[1]: continue
        a = lo
        while a < hi:
            n = min(hi - a, 8 * 1024 * 1024)
            try:
                d = os.pread(fd, n, a)
            except Exception:
                a += n; continue
            if not d:
                a += n; continue
            out.write(struct.pack('<QQ', a, len(d))); out.write(d)
            nreg += 1; nbytes += len(d)
            a += n
    out.close()
    os.close(fd)
    return nreg, nbytes


def parse_snap():
    data = open(SNAP, 'rb').read()
    regs = []
    i = 0
    while i + 16 <= len(data):
        lo, sz = struct.unpack_from('<QQ', data, i)
        regs.append((lo, data[i + 16:i + 16 + sz]))
        i += 16 + sz
    return regs


def readabs(regs, addr, n):
    for lo, body in regs:
        if lo <= addr < lo + len(body) and addr - lo + n <= len(body):
            return body[addr - lo:addr - lo + n]
    return None


def find_ctx(regs):
    """Search for DSP ctx by FUN_180535ae0 ctor markers:
    +0x24==40000.0f, +0x540874==1.0, +0x54087c==0.5, +0x54088c==1.0."""
    sig24 = struct.pack('<I', 0x472c4400)   # 40000.0f
    f1 = struct.pack('<f', 1.0)
    fhalf = struct.pack('<f', 0.5)
    cands = []
    for lo, body in regs:
        j = 0
        while True:
            j = body.find(sig24, j)
            if j < 0:
                break
            base = lo + j - 0x24
            if (readabs(regs, base + 0x540874, 4) == f1 and
                readabs(regs, base + 0x54087c, 4) == fhalf and
                readabs(regs, base + 0x54088c, 4) == f1):
                cands.append(base)
            j += 1
    return cands


def find_registry(regs):
    okc = {8193, 2049, 2048, 32768, 16384, 1024, 4096}
    hits = []
    for lo, body in regs:
        if len(body) < 0x2000: continue
        for off in range(0, len(body) - 64, 8):
            good = True
            for k in range(4):
                if off + 16 + 8 > len(body): good = False; break
                c = struct.unpack_from('<Q', body, off + k * 16)[0]
                if c not in okc: good = False; break
                p = struct.unpack_from('<Q', body, off + k * 16 + 8)[0]
                if readabs(regs, p, 4) is None: good = False; break
            if good: hits.append(lo + off)
    hits = sorted(set(hits))
    dedup = []
    for h in hits:
        if not dedup or h - dedup[-1] > 0x40:
            dedup.append(h)
    return dedup


def dump_targets(regs, ctx):
    out = {}
    def f32(addr):
        b = readabs(regs, addr, 4)
        return struct.unpack('<f', b)[0] if b else None
    def f64arr(addr, n):
        b = readabs(regs, addr, 8 * n)
        return list(struct.unpack('<%dd' % n, b)) if b and len(b) >= 8 * n else None
    out['scalars'] = {
        '0x24': f32(ctx + 0x24),
        '0x540870': f32(ctx + 0x540870),
        '0x540874': f32(ctx + 0x540874),
        '0x54087c': f32(ctx + 0x54087c),
        '0x540888': f32(ctx + 0x540888),
        '0x54088c': f32(ctx + 0x54088c),
    }
    out['bandconfig0'] = {
        'A': f32(ctx + 0x188),
        'B': f32(ctx + 0x188 + 0x04),
        'gamma': f32(ctx + 0x188 + 0x0c),
        'flag': readabs(regs, ctx + 0x188 + 0x10, 1),
    }
    for name, off, cnt in [('0x4c0528', 0x4c0528, 32),
                           ('0x3c0510', 0x3c0510, 32),
                           ('0x2c04f8', 0x2c04f8, 32)]:
        a = f64arr(ctx + off, cnt)
        if a is not None:
            out[name] = a
    return out


def main():
    os.system("pkill -9 -x reaper 2>/dev/null; pkill -9 -f '[y]abridge' 2>/dev/null; sleep 1")
    proc = subprocess.Popen(
        ['/usr/bin/reaper', '-nosplash', '-ignoreerrors',
         '/home/m/soothe-bt/render_long.rpp', '/home/m/re-tools/play.lua'],
        stdout=open('/dev/null', 'w'), stderr=subprocess.STDOUT)
    t0 = time.time(); host = None
    while time.time() - t0 < 60 and not host:
        host = find_host(); time.sleep(0.2)
    if not host:
        print('NO HOST'); return 1
    print('host', host, 'at %.1fs' % (time.time() - t0))
    time.sleep(8)
    for attempt in range(3):
        nreg, nbytes = snapshot(host)
        print('snapshot #%d: %d regs %.1f MB' % (attempt, nreg, nbytes / 1e6))
        if nbytes > 50e6:
            break
        time.sleep(3)
    if proc.poll() is None:
        proc.kill()
    regs = parse_snap()
    hits = find_registry(regs)
    rb = None
    for h in hits:
        b = readabs(regs, h, 8)
        if b and struct.unpack('<Q', b)[0] == 8193:
            rb = h; break
    print('registry base:', ('0x%x' % rb) if rb else 'NONE')
    cands = find_ctx(regs)
    print('ctx candidates:', [('0x%x' % c) for c in cands])
    if cands:
        ctx = cands[0]
        dump = dump_targets(regs, ctx)
        print(json.dumps(dump, indent=1, default=str))
        with open('/tmp/rtctx_live.json', 'w') as f:
            json.dump(dump, f, indent=1, default=str)
        print('saved /tmp/rtctx_live.json')
    return 0


if __name__ == '__main__':
    sys.exit(main())