"""Verify: preamble[3:7] = Tran[0], Tran[1] as int16 BE in 16-count units.
And first 20/10 NN block = Tran deltas starting at sample 2.
"""
import os, sys
sys.path.insert(0, ".")
from analysis.load_bundle import _parse_txt
from minimateplus.waveform_codec import walk_body, find_data_start


def s4(n):
    return n if n < 8 else n - 16


def i8(b):
    return b if b < 128 else b - 256


def main():
    for stem in ("M529LL1A.SP0", "M529LL1A.SS0", "M529LL1A.SV0"):
        path = f"decode-re/5-11-26/{stem}"
        with open(path, "rb") as f:
            raw = f.read()
        body = raw[43:-26]
        _, samples = _parse_txt(path + ".TXT")
        truth_T_16 = [round(v * 200) for v in samples["Tran"]]

        # Preamble parse
        T0_pre = int.from_bytes(body[3:5], "big", signed=True)
        T1_pre = int.from_bytes(body[5:7], "big", signed=True)
        print(f"\n=== {stem} ===")
        print(f"  Preamble T[0]={T0_pre} (truth {truth_T_16[0]})  T[1]={T1_pre} (truth {truth_T_16[1]})  match={T0_pre==truth_T_16[0] and T1_pre==truth_T_16[1]}")

        # First block
        start = find_data_start(body)
        blocks = walk_body(body, start)
        if not blocks:
            print(f"  no blocks found")
            continue

        # Assume first block = Tran deltas from sample 2
        first = blocks[0]
        T = [T0_pre, T1_pre]
        cur_T = T1_pre
        if first.tag_hi == 0x10:
            # Nibble pairs
            for byte in first.data:
                for nib in ((byte >> 4) & 0xF, byte & 0xF):
                    cur_T += s4(nib)
                    T.append(cur_T)
        elif first.tag_hi == 0x20:
            # int8 per byte
            for byte in first.data:
                cur_T += i8(byte)
                T.append(cur_T)

        # Compare against truth
        n_check = min(len(T), len(truth_T_16))
        match_count = sum(1 for i in range(n_check) if T[i] == truth_T_16[i])
        print(f"  First block type=0x{first.tag_hi:02x} NN=0x{first.tag_lo:02x} len={len(first.data)} → {len(T)} T samples decoded")
        print(f"  Tran predicted[0:10]: {T[:10]}")
        print(f"  Tran truth    [0:10]: {truth_T_16[:10]}")
        print(f"  Matches in first {n_check}: {match_count} / {n_check}")
        # Show where it diverges
        for i in range(n_check):
            if T[i] != truth_T_16[i]:
                print(f"  First divergence: sample {i}: pred={T[i]}, truth={truth_T_16[i]}")
                break


if __name__ == "__main__":
    main()