#!/usr/bin/env python3
from __future__ import annotations

import json
import re
import sys
from collections import Counter
from pathlib import Path


def load_text(path: Path) -> str:
    return path.read_text(encoding="utf-8", errors="ignore")


def main() -> int:
    root = Path(__file__).resolve().parent.parent

    front_globs = [
        "src/lib/**/*.ts",
        "src/lib/**/*.svelte",
        "src/routes/**/*.ts",
        "src/routes/**/*.svelte",
    ]

    # Match both invoke('cmd') and invoke<Type>('cmd')
    invoke_pat = re.compile(r"invoke(?:<[^>]*>)?\(\s*['\"]([^'\"]+)['\"]")
    # Match v2_* / runtime_* commands registered under any module namespace
    # (e.g. commands_v2::, qconnect_service::, future_module::). The inner
    # alternation ensures we still ignore legacy commands which never use
    # the v2_ or runtime_ prefix on the function name.
    registrations_pat = re.compile(r"::(v2_[A-Za-z0-9_]+|runtime_[A-Za-z0-9_]+)")

    front_paths = []
    for g in front_globs:
        front_paths.extend(root.glob(g))

    invokes: list[tuple[str, str]] = []
    for path in front_paths:
        text = load_text(path)
        rel = path.relative_to(root)
        for m in invoke_pat.finditer(text):
            line_no = text.count("\n", 0, m.start()) + 1
            invokes.append((m.group(1), f"{rel}:{line_no}"))

    lib_rs = load_text(root / "src-tauri/src/lib.rs")
    registered_v2 = set(registrations_pat.findall(lib_rs))

    # Legacy module roots: any tauri::generate_handler! entry whose final
    # leaf identifier is registered under one of these module paths counts
    # as a legacy command. The leaf is the last `::ident` before the
    # trailing comma in the handler list.
    legacy_module_roots = [
        "commands",
        "library::commands",
        "cast::commands",
        "cast::dlna::commands",
        "offline_cache::commands",
        "offline::commands",
        "network::commands",
        "lyrics::commands",
        "reco_store::commands",
        "updates",
        "config::favorites_cache",
        "config::legal_settings",
        "desktop_theme",
        "flatpak",
    ]
    registered_legacy: set[str] = set()
    for root_path in legacy_module_roots:
        # Match `<root_path>(::<segment>)*::<leaf>,` and capture the leaf.
        pat = re.compile(
            rf"{re.escape(root_path)}(?:::[A-Za-z0-9_]+)*::([A-Za-z0-9_]+)\s*,"
        )
        registered_legacy |= set(pat.findall(lib_rs))

    v2_ok: list[tuple[str, str]] = []
    missing_v2: list[tuple[str, str]] = []
    legacy_calls: list[tuple[str, str]] = []
    unknown: list[tuple[str, str]] = []

    for cmd, loc in invokes:
        if cmd.startswith("v2_") or cmd.startswith("runtime_"):
            if cmd in registered_v2:
                v2_ok.append((cmd, loc))
            else:
                missing_v2.append((cmd, loc))
        else:
            if cmd in registered_legacy:
                legacy_calls.append((cmd, loc))
            else:
                unknown.append((cmd, loc))

    summary = {
        "total_callsites": len(invokes),
        "v2_ok_callsites": len(v2_ok),
        "missing_v2_callsites": len(missing_v2),
        "legacy_callsites": len(legacy_calls),
        "unknown_callsites": len(unknown),
        "unique_total": len({c for c, _ in invokes}),
        "unique_v2_ok": len({c for c, _ in v2_ok}),
        "unique_missing_v2": len({c for c, _ in missing_v2}),
        "unique_legacy": len({c for c, _ in legacy_calls}),
        "unique_unknown": len({c for c, _ in unknown}),
    }

    report_dir = root / "tmp"
    report_dir.mkdir(parents=True, exist_ok=True)
    (report_dir / "frontend_invoke_summary.json").write_text(
        json.dumps(summary, indent=2), encoding="utf-8"
    )

    def write_tsv(name: str, rows: list[tuple[str, str]]) -> None:
        with (report_dir / name).open("w", encoding="utf-8") as fh:
            for cmd, loc in rows:
                fh.write(f"{cmd}\t{loc}\n")

    write_tsv("frontend_v2_ok_callsites.tsv", v2_ok)
    write_tsv("frontend_missing_v2_callsites.tsv", missing_v2)
    write_tsv("frontend_legacy_callsites.tsv", legacy_calls)
    write_tsv("frontend_unknown_callsites.tsv", unknown)

    print(json.dumps(summary, indent=2))
    print("\nTop missing_v2 commands:")
    for cmd, count in Counter(c for c, _ in missing_v2).most_common(20):
        print(f"{count}\t{cmd}")

    print("\nTop legacy commands:")
    for cmd, count in Counter(c for c, _ in legacy_calls).most_common(20):
        print(f"{count}\t{cmd}")

    # Hard fail if frontend still invokes any legacy command.
    if legacy_calls:
        return 1
    return 0


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