"""Golden-manifest tests for the Connac2 container extractor.

Runs against whatever MediaTek blobs exist on this host (skip otherwise).
Golden values observed from linux-firmware snapshot 2026-04-20; when a value
here fails against a newer snapshot, the blob changed — update the golden
value *and* note it in the changelog, don't silently absorb it.
"""
import os
import subprocess
import sys
import unittest
from pathlib import Path

REPO = Path(__file__).resolve().parent.parent
FW = Path(os.environ.get('MTK_FW_DIR', '/lib/firmware/mediatek'))

# Golden source of truth: dataset/history.jsonl (one record per
# linux-firmware revision, sha256-keyed). Any tested blob must be a known
# revision and its parse must match the recorded metadata. A new upstream
# build therefore fails here until the dataset is refreshed (by design):
#
#     python3 tools/fw_history.py firmware/linux-firmware -o dataset/history.jsonl
import json

HISTORY = json.loads(
    '[' + ','.join(l for l in
                   (REPO / 'dataset' / 'history.jsonl').read_text().splitlines()
                   if l) + ']')
BY_SHA = {r['sha256']: r for r in HISTORY}


def _expected(path: Path, sha: str):
    rec = BY_SHA.get(sha)
    if rec is None:
        raise AssertionError(
            f'{path.name}: sha {sha} is not a known linux-firmware revision '
            f'in dataset/history.jsonl — refresh the dataset (see comment '
            f'above) or verify the blob provenance')
    return rec


def parse(path: Path, out: Path) -> dict:
    out.mkdir(parents=True, exist_ok=True)
    sys.path.insert(0, str(REPO / 'tools'))
    import mtk_fw_extract as x
    return (x.carve_patch if 'patch' in path.name else x.carve_ram)(path, out)


class LayoutClosure(unittest.TestCase):
    """sum(region.len) + hidden trailer + table + trailer == file size."""

    def test_closure(self):
        blobs = sorted(FW.glob('mt79*_wm.bin')) + sorted(FW.glob('mt79*_wa.bin'))
        if not blobs:
            self.skipTest('no mediatek blobs on this host')
        import struct
        T = struct.Struct('<5B2s10s15sI')
        R = struct.Struct('<III4sIIBB14s')
        for p in blobs:
            with self.subTest(blob=p.name):
                d = p.read_bytes()
                n = d[len(d) - T.size + 2]
                tbl = len(d) - T.size - n * R.size
                data_end = sum(R.unpack_from(d, tbl + i * R.size)[5]
                               for i in range(n))
                self.assertEqual(
                    data_end + (tbl - data_end) + n * R.size + T.size, len(d),
                    'layout does not close')


class GoldenRAM(unittest.TestCase):
    """Parsed metadata must match the dataset record for the blob's sha."""

    def test_ram(self):
        import hashlib
        import sys as _sys
        _sys.path.insert(0, str(REPO / 'tools'))
        blobs = sorted(FW.glob('mt79*_wm.bin')) + sorted(FW.glob('mt79*_wa.bin'))
        if not blobs:
            self.skipTest('no mediatek blobs on this host')
        for p in blobs:
            with self.subTest(blob=p.name):
                d = p.read_bytes()
                rec = _expected(p, hashlib.sha256(d).hexdigest()[:16])
                info = parse(p, REPO / 'extracted' / 'test_ram')
                self.assertEqual(info['chip_id'], rec.get('chip_id'), p.name)
                self.assertEqual(info['eco'], rec.get('eco'), p.name)
                self.assertEqual(info['n_region'], rec.get('n_region'), p.name)
                self.assertEqual(info.get('hidden_trailer', {}).get('string'),
                                 rec.get('hidden'), p.name)
                self.assertEqual(info['build_date'], rec.get('trailer_date'),
                                 p.name)


class GoldenPatch(unittest.TestCase):

    def test_patch(self):
        import hashlib
        blobs = sorted(FW.glob('mt79*_rom_patch.bin'))
        if not blobs:
            self.skipTest('no mediatek blobs on this host')
        for p in blobs:
            with self.subTest(blob=p.name):
                d = p.read_bytes()
                rec = _expected(p, hashlib.sha256(d).hexdigest()[:16])
                info = parse(p, REPO / 'extracted' / 'test_patch')
                self.assertEqual(info['platform'], rec.get('platform'), p.name)
                self.assertEqual(info['n_region'], rec.get('n_section'), p.name)
                for sec in info['sections']:
                    self.assertEqual(sec['type'], '0x30002')
                    self.assertEqual(sec['enc_type'], 0)  # plaintext (F4)


if __name__ == '__main__':
    unittest.main(verbosity=2)