"""Build phase — content prep for static-content sites."""

import shutil
import subprocess
import tempfile
from pathlib import Path

from utils import EXCLUDE_FILES, env, parse_site_yaml, run_args


def build_static(site_dir, cfg):
    build_dir = site_dir / "build"
    html_dir = build_dir / "html"

    if build_dir.exists():
        shutil.rmtree(build_dir)

    content_dir = cfg["content_dir"]
    src = site_dir / content_dir if content_dir else site_dir

    if cfg["type"] == "static":
        print(f"Copying static content from {src}")
        with tempfile.TemporaryDirectory() as tmp:
            tmp_path = Path(tmp) / "html"
            shutil.copytree(src, tmp_path, dirs_exist_ok=True)
            for name in EXCLUDE_FILES:
                p = tmp_path / name
                if p.is_dir():
                    shutil.rmtree(p)
                elif p.exists():
                    p.unlink()
            build_dir.mkdir(parents=True)
            shutil.move(str(tmp_path), str(html_dir))

    elif cfg["type"] == "hugo":
        print(f"Building Hugo site from {src}")
        run_args(["hugo", "--source", str(src), "--destination", str(html_dir)])

    elif cfg["type"] == "mkdocs":
        print(f"Building MkDocs site from {src}")
        run_args(["mkdocs", "build", "-d", str(html_dir)], cwd=src)

    if cfg.get("tidy", True):
        print("Running tidy on HTML files...")
        for html_file in html_dir.rglob("*.html"):
            subprocess.run(
                ["tidy", "-modify", "-quiet",
                 "--wrap", "0", "--indent", "auto", "--indent-spaces", "2",
                 "--drop-empty-elements", "no", "--tidy-mark", "no",
                 "--show-warnings", "no", str(html_file)],
                check=False,
            )

    print(f"Build complete — content at {html_dir}")


def stage_artifacts(site_dir, cfg):
    """Snapshot caller-built outputs for the deploy phase."""
    staging_dir = site_dir / ".site-publish"
    if staging_dir.is_symlink():
        raise SystemExit("ERROR: .site-publish must not be a symbolic link")
    if staging_dir.exists():
        shutil.rmtree(staging_dir)
    staging_dir.mkdir()
    root = site_dir.resolve()

    for name, artifact in cfg["artifacts"].items():
        source = (site_dir / artifact["source"]).resolve()
        try:
            source.relative_to(root)
        except ValueError:
            raise SystemExit(f"ERROR: artifact {name}.source escapes the repository")
        if not source.is_dir():
            raise SystemExit(f"ERROR: artifact {name}.source is not a directory: {artifact['source']}")
        files = [entry for entry in source.rglob("*") if entry.is_file()]
        if not files:
            raise SystemExit(f"ERROR: artifact {name}.source has no files: {artifact['source']}")
        for entry in source.rglob("*"):
            if entry.is_symlink():
                try:
                    entry.resolve(strict=True).relative_to(root)
                except (FileNotFoundError, ValueError):
                    raise SystemExit(
                        f"ERROR: artifact {name}.source contains an unsafe symlink: {entry.relative_to(source)}"
                    )
        destination = staging_dir / name
        destination.mkdir()
        routes = [route for route in cfg["routes"] if route["artifact"] == name]
        targets = set()
        print(f"Staging artifact {name} from {artifact['source']}")
        for route in routes:
            route_root = destination / route["path"].lstrip("/")
            for entry in files:
                relative = entry.relative_to(source)
                target = route_root / relative
                if target in targets:
                    raise SystemExit(
                        f"ERROR: artifact {name} routes map more than once to {target.relative_to(destination)}"
                    )
                targets.add(target)
                target.parent.mkdir(parents=True, exist_ok=True)
                shutil.copy2(entry, target, follow_symlinks=True)

    print(f"Build complete — staged artifacts at {staging_dir}")


def cmd_build():
    site_dir = Path(env("SITE_DIR"))
    cfg = parse_site_yaml(site_dir)

    if not cfg["enabled"]:
        print("Site disabled — skipping build")
        return

    if cfg["mode"] == "multi":
        stage_artifacts(site_dir, cfg)
    else:
        build_static(site_dir, cfg)