import argparse
import glob
import json
import os
from collections import Counter


def _unesc(s: str) -> str:
    if "\\" in s:
        return s.encode("utf-8").decode("unicode_escape")
    return s


def _skip_ws_and_comments(text: str, i: int) -> int:
    n = len(text)
    while i < n:
        ch = text[i]
        if ch.isspace():
            i += 1
            continue
        if text.startswith("//", i):
            j = text.find("\n", i + 2)
            i = n if j == -1 else j + 1
            continue
        if text.startswith("/*", i):
            j = text.find("*/", i + 2)
            i = n if j == -1 else j + 2
            continue
        break
    return i


def _parse_string_literal(text: str, i: int) -> tuple[str, int]:
    quote = text[i]
    i += 1
    n = len(text)
    buf: list[str] = []
    while i < n:
        ch = text[i]
        if ch == "\\" and i + 1 < n:
            buf.append(ch)
            buf.append(text[i + 1])
            i += 2
            continue
        if ch == quote:
            i += 1
            break
        buf.append(ch)
        i += 1
    raw = "".join(buf)
    return _unesc(raw), i


def _parse_dart_map(file_path: str) -> dict[str, str]:
    with open(file_path, "r", encoding="utf-8") as f:
        text = f.read()
    start = text.find("{")
    end = text.rfind("}")
    if start == -1 or end == -1 or end <= start:
        return {}
    text = text[start + 1 : end]
    out: dict[str, str] = {}
    i = 0
    n = len(text)
    while i < n:
        i = _skip_ws_and_comments(text, i)
        if i >= n:
            break
        if text[i] not in ("'", '"'):
            i += 1
            continue
        key, i = _parse_string_literal(text, i)
        i = _skip_ws_and_comments(text, i)
        if i >= n or text[i] != ":":
            continue
        i += 1
        i = _skip_ws_and_comments(text, i)
        if i >= n or text[i] not in ("'", '"'):
            continue
        parts: list[str] = []
        while i < n and text[i] in ("'", '"'):
            part, i = _parse_string_literal(text, i)
            parts.append(part)
            i = _skip_ws_and_comments(text, i)
        out[key] = "".join(parts)
    return out


def _ascii_letter_ratio(s: str) -> float:
    if not s:
        return 0.0
    letters = sum(1 for ch in s if ("a" <= ch.lower() <= "z"))
    return letters / max(1, len(s))


def _looks_english_sentence(s: str) -> bool:
    if len(s.strip()) < 4:
        return False
    ratio = _ascii_letter_ratio(s)
    if ratio < 0.35:
        return False
    s_low = s.lower()
    common = [
        "please",
        "failed",
        "success",
        "error",
        "connect",
        "connection",
        "device",
        "network",
        "download",
        "upload",
        "translate",
        "translation",
        "record",
        "permission",
        "enable",
        "disable",
        "check",
        "try again",
        "stats",
        "threshold",
        "cost",
        "estimated",
        "data volume",
        "source text",
        "characters",
        "duration",
        "session",
        "history",
        "cleanup",
        "export",
        "available",
        "package",
        "remaining",
        "quota",
        "feature description",
        "most-used",
        "audio",
        "file size",
        "bytes",
        "interrupt",
        "reward",
        "credits",
        "vip",
        "expiration",
        "membership",
        "subscription",
        "subscribe",
        "purchase",
        "buy",
        "upgrade",
        "yearly",
        "monthly",
        "template",
        "community",
        "coming soon",
        "comparison",
        "detailed",
        "information",
        "select image source",
    ]
    return any(w in s_low for w in common)


def main() -> int:
    parser = argparse.ArgumentParser()
    parser.add_argument(
        "--dir",
        default=os.path.join("lib", "core", "translations", "language"),
        help="Directory containing language dart files",
    )
    parser.add_argument(
        "--baseline",
        default="en_us.dart",
        help="Baseline dart file to compare values against",
    )
    parser.add_argument(
        "--allowlist",
        default="",
        help="Path to JSON array of keys allowed to keep identical baseline values",
    )
    parser.add_argument(
        "--mode",
        choices=["exact", "englishy"],
        default="englishy",
        help="exact: value equals baseline; englishy: value equals baseline and looks English",
    )
    parser.add_argument(
        "--fail-on-missing",
        action="store_true",
        help="缺失 key 数超过 --allow-missing 时以非 0 退出（给 CI 用）",
    )
    parser.add_argument(
        "--allow-missing",
        type=int,
        default=0,
        help="允许的缺失 key 总数基线；配合 --fail-on-missing 卡住「只增不减」",
    )
    args = parser.parse_args()

    lang_dir = args.dir
    dart_files = sorted(glob.glob(os.path.join(lang_dir, "*.dart")))
    if not dart_files:
        raise SystemExit(f"No dart files found in {lang_dir}")

    allowlist: set[str] = set()
    if args.allowlist:
        with open(args.allowlist, "r", encoding="utf-8") as f:
            allowlist = set(json.load(f))

    parsed = {os.path.basename(p): _parse_dart_map(p) for p in dart_files}
    if args.baseline not in parsed:
        raise SystemExit(f"baseline not found: {args.baseline}")

    baseline = parsed[args.baseline]

    result: dict[str, dict] = {"baseline": args.baseline, "mode": args.mode, "files": {}}
    global_counter: Counter[str] = Counter()

    # 缺失 key 检查。
    #
    # ⚠️ 这一段是 2026-09-05 补的，此前本工具**结构上无法发现缺失的 key**：
    # 下面那个循环遍历的是「该语言文件已有的 key」，且对 baseline 里没有的直接
    # continue —— 一个 key 整个丢掉，它一声不吭。真实后果：tabTodo 在 30 个语言
    # 文件里根本不存在，GetX 静默回退英文，谁也没发现，直到有人逐个文件去数。
    # 以 zh_cn 为基准（它是文案的源语言，key 最全），不是以 en_us。
    ref_name = "zh_cn.dart" if "zh_cn.dart" in parsed else args.baseline
    ref_keys = set(parsed[ref_name])
    missing_counter: Counter[str] = Counter()

    for fn, kv in parsed.items():
        if fn == args.baseline:
            continue
        issues: list[dict] = []
        for k, v in kv.items():
            if k in allowlist:
                continue
            bv = baseline.get(k)
            if bv is None:
                continue
            if v != bv:
                continue
            if args.mode == "englishy" and not _looks_english_sentence(v):
                continue
            issues.append({"key": k, "value": v})
            global_counter[k] += 1
        missing = sorted(ref_keys - set(kv))
        for k in missing:
            missing_counter[k] += 1
        result["files"][fn] = {
            "count": len(issues),
            "items": issues,
            "missing_count": len(missing),
            "missing": missing,
        }

    total_missing = sum(f["missing_count"] for f in result["files"].values())
    result["summary"] = {
        "file_count": len(dart_files),
        "non_baseline_file_count": len(dart_files) - 1,
        "files_with_issues": sum(1 for f in result["files"].values() if f["count"] > 0),
        "total_issues": sum(f["count"] for f in result["files"].values()),
        "most_common_keys": [{"key": k, "count": c} for k, c in global_counter.most_common(50)],
        # 缺失统计
        "missing_reference": ref_name,
        "files_with_missing": sum(1 for f in result["files"].values() if f["missing_count"] > 0),
        "total_missing": total_missing,
        "most_missing_keys": [{"key": k, "count": c} for k, c in missing_counter.most_common(50)],
    }

    print(json.dumps(result, ensure_ascii=False, indent=2))
    # --fail-on-missing 给 CI 用：新增 key 只补了中文就提交时，这里非 0 退出。
    # 不默认开启——仓库现存约 8000 处历史缺失，一上来就红会让人直接把检查关掉。
    if args.fail_on_missing and total_missing > args.allow_missing:
        return 1
    return 0


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