#!/usr/bin/env python3
"""Regression check: re-emit each shipped panel from its GxEPD2 driver and diff
the result against the committed components/gxepd2/panel_*.h.

Compares only the structure the emitter authoritatively produces - the INIT /
WINDOW / REFRESH command sequences, plane count, plane-write command(s),
window_per_plane, and plane_invert - not the hand/diag-filled fields
(bits_per_pixel/palette/blank_code/plane_width/line_order), which carry
comments and names the emitter doesn't reproduce.

Catches two things: an emitter regression (reproduction breaks), and GxEPD2
upstream drift (a vendor bump changes a driver -> its panel now differs ->
review it). Exit non-zero on any unexpected mismatch.

    tools/check_descriptors.py                    # check all
    tools/check_descriptors.py -v                 # show the diff on a mismatch
    tools/check_descriptors.py GxEPD2_154_Z90c     # check just one (or more) models
    tools/check_descriptors.py GxEPD2_154_Z90c GxEPD2_270

Panels the emitter does not yet fully model (dual-region, see KNOWN_DIFF) are
expected to differ and don't fail; if one of them starts MATCHING, that's an
emitter improvement - remove it from KNOWN_DIFF. Panels with no GxEPD2 driver
source (a synthetic model with no third_party/GxEPD2/ .cpp of its own) are
skipped.
"""

import argparse
import ast
import difflib
import pathlib
import re
import sys

ROOT = pathlib.Path(__file__).resolve().parent.parent
sys.path.insert(0, str(ROOT / "tools"))
import capture as cap  # noqa: E402  (resolution + emit, reused)

PANEL_DIR = ROOT / "components" / "gxepd2"

# Panels the emitter's segmentation doesn't reproduce yet. The dual-region
# GDEY0579F51 used to live here; the emitter now models the region-select layer
# (per-region init/window/refresh, plane_width, paired-edges line doubling), so
# it reproduces and has been promoted out. A future panel the emitter can't yet
# segment goes here with a one-line why.
KNOWN_DIFF: set = set()


def registry():
    """(model, part) for every entry in display.py's PANELS."""
    tree = ast.parse((PANEL_DIR / "display.py").read_text())
    for node in ast.walk(tree):
        if isinstance(node, ast.Assign) and any(getattr(t, "id", None) == "PANELS" for t in node.targets):
            for key, val in zip(node.value.keys, node.value.values):
                yield key.value
            return


def parse_descriptor(text: str) -> dict:
    """Normalize a panel_*.h into the fields the emitter owns. Comments and
    array names are stripped, so only the command bytes / flags are compared."""
    text = re.sub(r"//.*", "", text)
    text = re.sub(r"/\*.*?\*/", "", text, flags=re.S)
    arrs = {name: [int(x, 16) for x in re.findall(r"0x[0-9A-Fa-f]+", body)]
            for name, body in re.findall(r"uint8_t\s+(\w+)\[\]\s*=\s*\{([^}]*)\}", text)}
    seqs = {}
    for seqname, body in re.findall(r"EpdCommand\s+(\w+)\[\]\s*=\s*\{(.*?)\};", text, flags=re.S):
        cmds = []
        for line in re.findall(r"\{([^}]*)\}", body):
            parts = [p.strip() for p in line.split(",")]
            op = int(parts[0], 16)
            data = tuple(arrs.get(parts[1], [])) if parts[1] != "nullptr" else ()
            cmds.append((op, data, "true" in line))
        role = ("INIT" if "INIT" in seqname else "WINDOW" if "WINDOW" in seqname
                else "REFRESH" if "REFRESH" in seqname else seqname)
        seqs.setdefault(role, cmds)  # first WINDOW_SEQ wins (window_sequence[0])

    def field(name, default="?"):
        m = re.search(rf"\.{name}\s*=\s*([^,\n]+)", text)
        return m.group(1).strip() if m else default

    return {
        "INIT": seqs.get("INIT"),
        "WINDOW": seqs.get("WINDOW", []),
        "REFRESH": seqs.get("REFRESH"),
        "plane_count": field("plane_count"),
        "plane_write_cmd": field("plane_write_cmd"),
        "window_per_plane": field("window_per_plane", "false"),
        "plane_invert": field("plane_invert"),
    }


def check(model: str, catalog: dict, verbose: bool) -> str:
    """Returns 'MATCH', 'DIFF', 'XFAIL', 'XPASS', 'SKIP', or 'ERROR'."""
    panel_h = PANEL_DIR / cap.filename_of(model)
    if not panel_h.exists():
        return "SKIP"
    src_rel, _, _ = cap.resolve_source(model, catalog)
    if src_rel is None:
        return "SKIP"  # no GxEPD2 driver to re-emit from (e.g. synthetic variant)
    try:
        generated = cap.capture(model, catalog, debug=False, cxx="g++", keep=False)
    except SystemExit as e:
        print(f"    {e}", file=sys.stderr)
        return "ERROR"
    g, h = parse_descriptor(generated), parse_descriptor(panel_h.read_text())
    same = g == h
    expected_diff = model in KNOWN_DIFF
    if same:
        return "XPASS" if expected_diff else "MATCH"
    if expected_diff:
        return "XFAIL"
    if verbose:
        for k in g:
            if g[k] != h[k]:
                print(f"    {k}:\n      emitted : {g[k]}\n      committed: {h[k]}", file=sys.stderr)
    return "DIFF"


def main() -> None:
    ap = argparse.ArgumentParser(description=__doc__, formatter_class=argparse.RawDescriptionHelpFormatter)
    ap.add_argument("models", nargs="*", help="only check these registry keys (default: check every registered panel)")
    ap.add_argument("-v", "--verbose", action="store_true", help="show the fields that differ on a mismatch")
    args = ap.parse_args()

    all_models = list(registry())
    if args.models:
        unknown = [m for m in args.models if m not in all_models]
        if unknown:
            for m in unknown:
                hint = difflib.get_close_matches(m, all_models, n=3)
                msg = f"not in display.py's PANELS: {m}"
                if hint:
                    msg += "\ndid you mean: " + ", ".join(hint)
                print(msg, file=sys.stderr)
            sys.exit(1)
        models = args.models
    else:
        models = all_models

    catalog = cap.load_catalog()
    results = {}
    for model in models:
        # capture.py prints its own [capture] line to stderr; keep output tidy.
        res = check(model, catalog, args.verbose)
        results[model] = res
        print(f"  {res:<6} {model}")

    bad = [m for m, r in results.items() if r in ("DIFF", "ERROR", "XPASS")]
    n_match = sum(1 for r in results.values() if r == "MATCH")
    print(f"\n{n_match} reproduced, {sum(1 for r in results.values() if r=='XFAIL')} known-diff, "
          f"{sum(1 for r in results.values() if r=='SKIP')} skipped.")
    if bad:
        print("\nFAILURES:")
        for m in bad:
            why = {"DIFF": "command structure changed (emitter regression or GxEPD2 drift) - review",
                   "ERROR": "capture failed to build/run",
                   "XPASS": "now reproduces - remove from KNOWN_DIFF"}[results[m]]
            print(f"  {results[m]:<6} {m}: {why}")
        sys.exit(1)
    print("OK")


if __name__ == "__main__":
    main()