from __future__ import annotations

import argparse
import json
import sys
from pathlib import Path

PROJECT_ROOT = Path(__file__).resolve().parents[1]


def _open_driver(width: int, height: int):
    from selenium import webdriver
    from selenium.webdriver.chrome.options import Options
    from selenium.webdriver.chrome.service import Service

    options = Options()
    options.add_argument("--headless=new")
    options.add_argument("--no-sandbox")
    options.add_argument("--disable-dev-shm-usage")
    options.add_argument(f"--window-size={width},{height}")

    candidates = [
        PROJECT_ROOT / "chromedriver",
        PROJECT_ROOT / "chromedriver.exe",
    ]
    last_err: Exception | None = None
    for path in candidates:
        if not path.is_file():
            continue
        try:
            driver = webdriver.Chrome(service=Service(str(path)), options=options)
            break
        except Exception as exc:  # pragma: no cover - environment dependent
            last_err = exc
    else:
        try:
            driver = webdriver.Chrome(options=options)
        except Exception as exc:  # pragma: no cover - environment dependent
            raise RuntimeError(f"selenium init failed: {last_err or exc}") from exc

    driver.execute_cdp_cmd(
        "Emulation.setDeviceMetricsOverride",
        {
            "width": width,
            "height": height,
            "deviceScaleFactor": 1,
            "mobile": False,
        },
    )
    return driver


def check_final_html(path: Path, *, width: int, height: int, tolerance: int) -> dict:
    driver = _open_driver(width, height)
    try:
        driver.get(path.resolve().as_uri())
        result = driver.execute_script(
            r"""
            const de = document.documentElement;
            const body = document.body;
            const slide = document.querySelector('.slide');
            const slideRect = slide ? slide.getBoundingClientRect() : null;
            const measure = (el) => ({
              clientWidth: el.clientWidth,
              clientHeight: el.clientHeight,
              scrollWidth: el.scrollWidth,
              scrollHeight: el.scrollHeight,
            });
            return {
              viewport: {
                innerWidth: window.innerWidth,
                innerHeight: window.innerHeight,
              },
              documentElement: measure(de),
              body: measure(body),
              slide: slideRect ? {
                x: slideRect.x,
                y: slideRect.y,
                width: slideRect.width,
                height: slideRect.height,
                right: slideRect.right,
                bottom: slideRect.bottom,
              } : null,
            };
            """
        )
    finally:
        driver.quit()

    failures: list[str] = []
    vp = result["viewport"]
    doc = result["documentElement"]
    body = result["body"]
    slide = result.get("slide")

    if doc["scrollWidth"] > vp["innerWidth"] + tolerance:
        failures.append(
            f"document horizontal scroll: {doc['scrollWidth']} > {vp['innerWidth']}"
        )
    if doc["scrollHeight"] > vp["innerHeight"] + tolerance:
        failures.append(
            f"document vertical scroll: {doc['scrollHeight']} > {vp['innerHeight']}"
        )
    if body["scrollWidth"] > vp["innerWidth"] + tolerance:
        failures.append(f"body horizontal scroll: {body['scrollWidth']} > {vp['innerWidth']}")
    if body["scrollHeight"] > vp["innerHeight"] + tolerance:
        failures.append(f"body vertical scroll: {body['scrollHeight']} > {vp['innerHeight']}")
    if not slide:
        failures.append(".slide not found")
    else:
        if abs(slide["width"] - width) > tolerance or abs(slide["height"] - height) > tolerance:
            failures.append(
                f"slide size is {slide['width']}x{slide['height']}, expected {width}x{height}"
            )
        if slide["x"] < -tolerance or slide["y"] < -tolerance:
            failures.append(f"slide origin out of viewport: x={slide['x']}, y={slide['y']}")
        if slide["right"] > vp["innerWidth"] + tolerance:
            failures.append(f"slide right edge exceeds viewport: {slide['right']} > {vp['innerWidth']}")
        if slide["bottom"] > vp["innerHeight"] + tolerance:
            failures.append(f"slide bottom edge exceeds viewport: {slide['bottom']} > {vp['innerHeight']}")

    return {
        "path": str(path),
        "passed": not failures,
        "failures": failures,
        "metrics": result,
    }


def _run_id_to_final_html(run_id: str) -> Path:
    return PROJECT_ROOT / "data" / "runs" / run_id / "phase_z2" / "final.html"


def main(argv: list[str] | None = None) -> int:
    parser = argparse.ArgumentParser()
    parser.add_argument("run_ids", nargs="+")
    parser.add_argument("--width", type=int, default=1280)
    parser.add_argument("--height", type=int, default=720)
    parser.add_argument("--tolerance", type=int, default=1)
    parser.add_argument("--write-report", type=Path)
    args = parser.parse_args(argv)

    reports = []
    exit_code = 0
    for run_id in args.run_ids:
        path = _run_id_to_final_html(run_id)
        if not path.is_file():
            report = {
                "path": str(path),
                "passed": False,
                "failures": ["final.html not found"],
                "metrics": None,
            }
        else:
            report = check_final_html(
                path,
                width=args.width,
                height=args.height,
                tolerance=args.tolerance,
            )
        reports.append({"run_id": run_id, **report})
        status = "PASS" if report["passed"] else "FAIL"
        print(f"{run_id}: {status}")
        for failure in report["failures"]:
            print(f"  - {failure}")
        if not report["passed"]:
            exit_code = 1

    if args.write_report:
        args.write_report.parent.mkdir(parents=True, exist_ok=True)
        args.write_report.write_text(
            json.dumps({"reports": reports}, ensure_ascii=False, indent=2),
            encoding="utf-8",
        )
    return exit_code


if __name__ == "__main__":
    raise SystemExit(main(sys.argv[1:]))