#!/usr/bin/env python3
"""Re-verify DEAD_CODE_REPORT.md entries against the full repo.

Vulture only sees Python, so FastAPI route handlers called from
electron/main.js or the React frontend get false-flagged as unused.
This script re-checks each entry by scanning the symbol name across
backend/, electron/, frontend/src/ AND by scanning likely HTTP path
strings for routes, then buckets findings.
"""
from __future__ import annotations
import re
import sys
from pathlib import Path

ROOT = Path(__file__).resolve().parent.parent
REPORT = ROOT / "DEAD_CODE_REPORT.md"
OUT = ROOT / "DEAD_CODE_TRIAGE.md"

SEARCH_ROOTS = ["backend", "electron", "frontend/src"]
SKIP_DIRS = {"__pycache__", "node_modules", "dist", ".venv",
             ".instagram-mcp.bak"}
SKIP_PARTS = (".bak",)
SOURCE_EXTS = {".py", ".js", ".jsx", ".ts", ".tsx", ".mjs", ".cjs"}

SECTION_RE = re.compile(r"^### `([^`]+)`")
ENTRY_RE = re.compile(r"^- \*\*([A-Za-z_][A-Za-z0-9_]*)\*\*")
ROUTE_DECORATOR_RE = re.compile(
    r"@[\w.]+\.(get|post|put|patch|delete|websocket)\(\s*['\"]([^'\"]+)['\"]"
)


def iter_source_files() -> list[Path]:
    files: list[Path] = []
    for root in SEARCH_ROOTS:
        base = ROOT / root
        if not base.exists():
            continue
        for path in base.rglob("*"):
            if not path.is_file() or path.suffix not in SOURCE_EXTS:
                continue
            parts = set(path.parts)
            if parts & SKIP_DIRS:
                continue
            if any(p.endswith(SKIP_PARTS) for p in path.parts):
                continue
            files.append(path)
    return files


_ALL_FILES_CACHE: list[tuple[Path, str]] = []


def _load_corpus() -> list[tuple[Path, str]]:
    global _ALL_FILES_CACHE
    if _ALL_FILES_CACHE:
        return _ALL_FILES_CACHE
    corpus: list[tuple[Path, str]] = []
    for path in iter_source_files():
        try:
            corpus.append((path, path.read_text(errors="ignore")))
        except OSError:
            continue
    _ALL_FILES_CACHE = corpus
    return corpus


def file_count_matching(pattern: re.Pattern[str],
                        exclude_file: str) -> int:
    exclude = (ROOT / exclude_file).resolve()
    n = 0
    for path, text in _load_corpus():
        if path.resolve() == exclude:
            continue
        if pattern.search(text):
            n += 1
    return n


def extract_route_paths(source_file: Path, symbol: str) -> list[str]:
    if not source_file.exists():
        return []
    try:
        lines = source_file.read_text().splitlines()
    except Exception:
        return []
    paths: list[str] = []
    for i, line in enumerate(lines):
        if f"def {symbol}(" in line or f"def {symbol} " in line:
            for j in range(max(0, i - 5), i):
                m = ROUTE_DECORATOR_RE.search(lines[j])
                if m:
                    paths.append(m.group(2))
    return paths


def classify(source_file: str, symbol: str) -> tuple[str, str]:
    src_path = ROOT / source_file
    route_paths = extract_route_paths(src_path, symbol)
    if route_paths:
        for p in route_paths:
            pat = re.compile(re.escape(p))
            if file_count_matching(pat, source_file) > 0:
                return "HTTP_LIVE", f"route path '{p}' referenced elsewhere"
        return "AMBIGUOUS", f"route handler but no callers for {route_paths}"
    pat = re.compile(rf"\b{re.escape(symbol)}\b")
    n = file_count_matching(pat, source_file)
    if n == 0:
        if symbol.startswith("_"):
            return "VERIFIED_DEAD", "private symbol, zero external refs"
        return "AMBIGUOUS", "zero refs but public symbol (manual review)"
    return "AMBIGUOUS", f"{n} other file(s) reference symbol"


def parse_report() -> list[tuple[str, str, str]]:
    entries: list[tuple[str, str, str]] = []
    current_file = ""
    current_section = ""
    for raw in REPORT.read_text().splitlines():
        if raw.startswith("## "):
            current_section = raw[3:].strip()
            current_file = ""
            continue
        m = SECTION_RE.match(raw)
        if m:
            current_file = m.group(1)
            continue
        m = ENTRY_RE.match(raw)
        if m and current_file and current_section in (
            "Unused Functions", "Unused Consts"
        ):
            entries.append((current_file, m.group(1), current_section))
    return entries


def main() -> int:
    if not REPORT.exists():
        print(f"missing {REPORT}", file=sys.stderr)
        return 1
    buckets: dict[str, list[str]] = {
        "VERIFIED_DEAD": [], "HTTP_LIVE": [], "AMBIGUOUS": []
    }
    for src, sym, section in parse_report():
        bucket, evidence = classify(src, sym)
        buckets[bucket].append(f"- `{src}` :: **{sym}** ({section}) {evidence}")
    out = ["# Dead Code Triage", ""]
    out.append("_Generated by `scripts/triage-deadcode.py`. "
               "Source: `DEAD_CODE_REPORT.md`._")
    out.append("")
    for name in ("VERIFIED_DEAD", "HTTP_LIVE", "AMBIGUOUS"):
        items = buckets[name]
        out.append(f"## {name} ({len(items)})")
        out.append("")
        out.extend(items if items else ["_(none)_"])
        out.append("")
    OUT.write_text("\n".join(out))
    for name in ("VERIFIED_DEAD", "HTTP_LIVE", "AMBIGUOUS"):
        print(f"{name}: {len(buckets[name])}")
    print(f"wrote {OUT.relative_to(ROOT)}")
    return 0


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