"""Single-command release builder for DataTools.

PyInstaller can't cross-compile — to produce a Windows .exe you run
this on Windows, for a Mac .dmg you run it on macOS, for a Linux
AppImage you run it on Linux. One script, one OS at a time.

What this script does (in order):
    1. Preflight — checks PyInstaller, Pillow, and the platform's
       packager (Inno Setup on Win / hdiutil + ditto on Mac /
       appimagetool on Linux) are reachable. Bails with install
       instructions if anything is missing.
    2. Generates icon.ico / icon.icns / icon.png from the PNG asset.
    3. Runs PyInstaller against build/datatools.spec.
    4. Wraps the PyInstaller output into:
         * Windows:  DataTools-<ver>-win-setup.exe (Inno Setup)
                  +  DataTools-<ver>-win-portable.zip
         * macOS:    DataTools-<ver>-mac.dmg
                  +  DataTools-<ver>-mac-portable.zip
         * Linux:    DataTools-<ver>-linux-x86_64.AppImage
    5. Prints what landed in dist/ and the byte sizes.

Usage:
    python build/make_release.py                  # build everything for this OS
    python build/make_release.py --preflight      # check tooling, don't build
    python build/make_release.py --skip-installer # only the portable zip
    python build/make_release.py --skip-portable  # only the installer
    python build/make_release.py --clean          # wipe dist/ first

Run from the repo root or from build/ — either works.
"""

from __future__ import annotations

import argparse
import platform
import re
import shutil
import subprocess
import sys
from pathlib import Path

REPO = Path(__file__).resolve().parent.parent
BUILD = REPO / "build"
DIST = REPO / "dist"


# ---------------------------------------------------------------------------
# Output helpers — colourless so logs stay readable in any terminal/CI tail.
# ---------------------------------------------------------------------------


def _step(msg: str) -> None:
    print(f"\n==> {msg}", flush=True)


def _ok(msg: str) -> None:
    print(f"    ok: {msg}", flush=True)


def _warn(msg: str) -> None:
    print(f"    warn: {msg}", flush=True)


def _err(msg: str) -> None:
    print(f"    ERROR: {msg}", file=sys.stderr, flush=True)


def _run(cmd: list[str], cwd: Path | None = None, env: dict | None = None) -> None:
    """Run *cmd*, stream output, exit on failure with a useful banner."""
    printable = " ".join(map(str, cmd))
    print(f"    $ {printable}", flush=True)
    try:
        subprocess.run(cmd, check=True, cwd=cwd or REPO, env=env)
    except subprocess.CalledProcessError as e:
        _err(f"command failed (exit {e.returncode}): {printable}")
        sys.exit(e.returncode)
    except FileNotFoundError:
        _err(f"command not found: {cmd[0]}")
        sys.exit(127)


# ---------------------------------------------------------------------------
# Platform detection
# ---------------------------------------------------------------------------


def _detect_platform() -> str:
    """Return ``win`` / ``mac`` / ``linux`` based on sys.platform."""
    p = sys.platform
    if p.startswith("win"):
        return "win"
    if p == "darwin":
        return "mac"
    if p.startswith("linux"):
        return "linux"
    _err(f"unsupported platform {p!r}; this script handles win/mac/linux only.")
    sys.exit(2)


# ---------------------------------------------------------------------------
# Version — single source of truth in src/__init__.py
# ---------------------------------------------------------------------------


def _read_version() -> str:
    init_py = (REPO / "src" / "__init__.py").read_text(encoding="utf-8")
    m = re.search(r'__version__\s*=\s*["\']([^"\']+)["\']', init_py)
    if not m:
        _err("could not parse __version__ from src/__init__.py")
        sys.exit(1)
    return m.group(1)


# ---------------------------------------------------------------------------
# Preflight — check tooling before doing anything destructive
# ---------------------------------------------------------------------------


def _have_module(name: str) -> bool:
    try:
        __import__(name)
        return True
    except ImportError:
        return False


def _have_command(name: str) -> bool:
    return shutil.which(name) is not None


# Per-platform install hints. The error messages quote these so a buyer
# building from source isn't left guessing what to install next.
_INSTALL_HINTS = {
    "pyinstaller": "pip install pyinstaller",
    "pil":         "pip install pillow",
    "iscc":        "Inno Setup (Windows): https://jrsoftware.org/isdl.php  — install, then re-open the shell so iscc lands on PATH.",
    "hdiutil":     "ships with macOS — if it's missing your Mac install is broken.",
    "ditto":       "ships with macOS — if it's missing your Mac install is broken.",
    "appimagetool": "Linux: download appimagetool-x86_64.AppImage from https://github.com/AppImage/AppImageKit/releases, chmod +x, drop on PATH.",
}


def preflight(target: str) -> None:
    """Verify every tool the target build needs is reachable; exit if not."""
    _step(f"preflight ({target})")

    missing: list[tuple[str, str]] = []

    # Python-side deps — same on every platform. The ``_INSTALL_HINTS``
    # lookup uses lowercase keys so module name capitalization doesn't
    # need to match.
    for mod in ("PyInstaller", "PIL"):
        if not _have_module(mod):
            hint = _INSTALL_HINTS.get(mod.lower(), f"pip install {mod}")
            missing.append((mod.lower(), hint))
        else:
            _ok(f"{mod} importable")

    # PyInstaller's CLI must also be reachable as a binary, not just as
    # an importable module — the spec is invoked via the ``pyinstaller``
    # command. ``python -m PyInstaller`` is a fine fallback so don't
    # hard-fail if only the CLI binary is missing.
    if _have_command("pyinstaller"):
        _ok("pyinstaller on PATH")
    else:
        _warn("pyinstaller binary not on PATH — will fall back to `python -m PyInstaller`")

    # Platform-specific packagers.
    if target == "win":
        if _have_command("iscc"):
            _ok("Inno Setup (iscc) on PATH")
        else:
            missing.append(("iscc", _INSTALL_HINTS["iscc"]))
    elif target == "mac":
        for tool in ("hdiutil", "ditto"):
            if _have_command(tool):
                _ok(f"{tool} on PATH")
            else:
                missing.append((tool, _INSTALL_HINTS[tool]))
    elif target == "linux":
        if _have_command("appimagetool"):
            _ok("appimagetool on PATH")
        else:
            missing.append(("appimagetool", _INSTALL_HINTS["appimagetool"]))

    if missing:
        _err("missing prerequisites:")
        for name, hint in missing:
            print(f"      - {name}: {hint}", file=sys.stderr)
        sys.exit(1)

    _ok("all prerequisites present")


# ---------------------------------------------------------------------------
# Build steps
# ---------------------------------------------------------------------------


def step_generate_icons() -> None:
    _step("generate icons")
    _run([sys.executable, str(BUILD / "generate_icons.py")])


def step_pyinstaller(clean: bool) -> None:
    _step("pyinstaller bundle")
    # Use ``python -m PyInstaller`` so we don't depend on the binary
    # being on PATH (Windows users frequently see this — pip's
    # Scripts/ dir isn't auto-added).
    cmd = [sys.executable, "-m", "PyInstaller",
           str(BUILD / "datatools.spec"),
           "--noconfirm"]
    if clean:
        cmd.append("--clean")
    _run(cmd)


def step_package_win(version: str, do_installer: bool, do_portable: bool) -> list[Path]:
    out: list[Path] = []
    if do_installer:
        _step("Windows installer (Inno Setup)")
        _run(["iscc", f"/DAppVersion={version}", str(BUILD / "installer.iss")])
        out.append(DIST / f"DataTools-{version}-win-setup.exe")
    if do_portable:
        _step("Windows portable .zip")
        _run([sys.executable, str(BUILD / "build_portable_zip.py"), "win", version])
        out.append(DIST / f"DataTools-{version}-win-portable.zip")
    return out


def step_package_mac(version: str, do_installer: bool, do_portable: bool) -> list[Path]:
    out: list[Path] = []
    if do_installer:
        _step("macOS DMG (installer)")
        _run(["bash", str(BUILD / "macos" / "build_dmg.sh"), version])
        out.append(DIST / f"DataTools-{version}-mac.dmg")
    if do_portable:
        _step("macOS portable .zip")
        _run(["bash", str(BUILD / "macos" / "build_zip.sh"), version])
        out.append(DIST / f"DataTools-{version}-mac-portable.zip")
    return out


def step_package_linux(version: str, do_installer: bool, do_portable: bool) -> list[Path]:
    # On Linux the AppImage IS the portable. We ignore the two flags
    # and always produce the single file — splitting wouldn't add
    # value.
    if not (do_installer or do_portable):
        return []
    _step("Linux AppImage")
    _run(["bash", str(BUILD / "appimage" / "build.sh"), version])
    return [DIST / f"DataTools-{version}-linux-x86_64.AppImage"]


# ---------------------------------------------------------------------------
# Orchestration
# ---------------------------------------------------------------------------


def _summarise(outputs: list[Path]) -> None:
    _step("done — outputs")
    if not outputs:
        _warn("no files produced (everything skipped via flags)")
        return
    for p in outputs:
        if p.exists():
            size_mb = p.stat().st_size / (1024 * 1024)
            print(f"    {p.relative_to(REPO)}  ({size_mb:.1f} MB)")
        else:
            _warn(f"expected output missing: {p.relative_to(REPO)}")


def main() -> int:
    parser = argparse.ArgumentParser(
        prog="make_release.py",
        description=(
            "Build the installer + portable zip for the current OS. "
            "Cross-compilation isn't supported by PyInstaller — run "
            "this once per platform you want to target."
        ),
        formatter_class=argparse.RawDescriptionHelpFormatter,
    )
    parser.add_argument(
        "--platform", choices=("auto", "win", "mac", "linux"), default="auto",
        help="Override OS detection (mostly for testing). Default: auto.",
    )
    parser.add_argument(
        "--preflight", action="store_true",
        help="Check tooling and exit without building.",
    )
    parser.add_argument(
        "--clean", action="store_true",
        help="Wipe dist/ before building.",
    )
    parser.add_argument(
        "--skip-installer", action="store_true",
        help="Don't build the OS installer (.exe / .dmg).",
    )
    parser.add_argument(
        "--skip-portable", action="store_true",
        help="Don't build the portable .zip.",
    )
    args = parser.parse_args()

    target = _detect_platform() if args.platform == "auto" else args.platform
    version = _read_version()
    do_installer = not args.skip_installer
    do_portable = not args.skip_portable

    print(f"DataTools release builder")
    print(f"  target:    {target} (host: {platform.platform()})")
    print(f"  version:   {version}")
    print(f"  installer: {'yes' if do_installer else 'no'}")
    print(f"  portable:  {'yes' if do_portable else 'no'}")
    print(f"  dist dir:  {DIST}")

    if target != _detect_platform():
        _warn(
            f"--platform {target} but host is {_detect_platform()}. "
            "PyInstaller can't cross-compile — the bundle will be for "
            "the HOST, only the packaging step will follow your override. "
            "Useful only for testing the packager paths."
        )

    preflight(target)
    if args.preflight:
        return 0

    if args.clean and DIST.exists():
        _step(f"cleaning {DIST}")
        shutil.rmtree(DIST)

    step_generate_icons()
    step_pyinstaller(clean=args.clean)

    if target == "win":
        outputs = step_package_win(version, do_installer, do_portable)
    elif target == "mac":
        outputs = step_package_mac(version, do_installer, do_portable)
    else:
        outputs = step_package_linux(version, do_installer, do_portable)

    _summarise(outputs)
    return 0


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