"""
PyInstaller build script for Label Printer GUI
Run this to create a standalone Windows executable.

IMPORTANT: This script MUST be run on Windows to generate a Windows .exe file.
If run on Linux/macOS, it will create a Linux/macOS binary that won't work on Windows.

To build for Windows:
1. Copy this project to a Windows machine
2. Install dependencies: pip install -r requirements_windows.txt
3. Run this script: python build_exe.py
4. The Windows .exe will be created in the dist/ folder

GhostScript bundling
--------------------
If GhostScript is installed on this build machine the script will
automatically copy the required files into conf\\ghostscript\\ before
calling PyInstaller so they are embedded in LabelPrinter.exe.
The target machine then needs NO separate GhostScript install.
"""

import os
import sys
import subprocess
import shutil

# Get the current directory
script_dir = os.path.dirname(os.path.abspath(__file__))


def prepare_ghostscript():
    """
    Find the system GhostScript installation and copy the minimum files
    needed for bundling into conf\\ghostscript\\.

    Files copied:
        conf\\ghostscript\\bin\\gswin64c.exe  (or 32-bit variant)
        conf\\ghostscript\\bin\\gsdll64.dll
        conf\\ghostscript\\lib\\*.ps          (PostScript init files)

    Returns True if GhostScript was found and prepared, False otherwise.
    """
    import glob

    gs_exe = None
    gs_dll = None
    gs_lib = None

    for pf in [r"C:\Program Files", r"C:\Program Files (x86)"]:
        gs_base = os.path.join(pf, "gs")
        if not os.path.isdir(gs_base):
            continue
        # Iterate versions newest-first
        for ver_dir in sorted(os.listdir(gs_base), reverse=True):
            bin_dir = os.path.join(gs_base, ver_dir, "bin")
            lib_dir = os.path.join(gs_base, ver_dir, "lib")
            if os.path.exists(os.path.join(bin_dir, "gswin64c.exe")):
                gs_exe = os.path.join(bin_dir, "gswin64c.exe")
                gs_dll = os.path.join(bin_dir, "gsdll64.dll")
                gs_lib = lib_dir
                break
            if os.path.exists(os.path.join(bin_dir, "gswin32c.exe")):
                gs_exe = os.path.join(bin_dir, "gswin32c.exe")
                gs_dll = os.path.join(bin_dir, "gsdll32.dll")
                gs_lib = lib_dir
                break
        if gs_exe:
            break

    if not gs_exe:
        print("  WARNING: GhostScript not found on this machine.")
        print("  The exe will still build but GhostScript will NOT be bundled.")
        print("  Install GhostScript from https://ghostscript.com/releases/gsdnld.html")
        print("  then rebuild for sharp vector-quality printing.")
        return False

    dest_bin = os.path.join("conf", "ghostscript", "bin")
    dest_lib = os.path.join("conf", "ghostscript", "lib")
    os.makedirs(dest_bin, exist_ok=True)
    os.makedirs(dest_lib, exist_ok=True)

    print(f"  GhostScript found: {os.path.dirname(gs_exe)}")

    shutil.copy2(gs_exe, dest_bin)
    print(f"  Copied: {os.path.basename(gs_exe)}")

    if os.path.exists(gs_dll):
        shutil.copy2(gs_dll, dest_bin)
        print(f"  Copied: {os.path.basename(gs_dll)}")

    count = 0
    for ps_file in glob.glob(os.path.join(gs_lib, "*.ps")):
        shutil.copy2(ps_file, dest_lib)
        count += 1
    print(f"  Copied {count} .ps init files from lib/")

    print(f"  GhostScript prepared in conf\\ghostscript\\")
    return True


if __name__ == '__main__':
    print("=" * 60)
    print("Label Printer GUI - PyInstaller Build")
    print("=" * 60)

    # Change to script directory so relative paths work
    os.chdir(script_dir)

    # Step 1: Prepare GhostScript for bundling (Windows only)
    if sys.platform == "win32":
        print("\n[1/2] Preparing GhostScript for bundling...")
        prepare_ghostscript()
    else:
        print("\n[1/2] Skipping GhostScript prep (non-Windows build machine)")

    # Step 2: Build with PyInstaller using the handcrafted spec file.
    # The spec's Python code auto-detects conf\\ghostscript\\ and includes it.
    print("\n[2/2] Building standalone executable via LabelPrinter.spec...")
    print("This may take a few minutes...\n")

    try:
        result = subprocess.run(
            ['pyinstaller', 'LabelPrinter.spec',
             '--distpath=./dist', '--workpath=./build', '-y'],
            check=True,
        )

        print("\n" + "=" * 60)
        print("Build Complete!")
        print("=" * 60)
        print("\nExecutable location: ./dist/LabelPrinter.exe")
        print("\nBundled components:")
        print("  - GhostScript (vector-quality printing)")
        print("  - SumatraPDF  (fallback printing)")
        print("  - SVG templates, conf files")
        print("\nYou can now:")
        print("  1. Double-click LabelPrinter.exe to run")
        print("  2. Copy the dist\\ folder to target machines")
        print("  3. No extra software installation required on target machines")
        print("\nNote: First run may take a moment as Kivy initializes")
    except subprocess.CalledProcessError as e:
        print("\n" + "=" * 60)
        print("Build Failed!")
        print("=" * 60)
        print(f"\nError code: {e.returncode}")
        print("\nPlease check the error messages above for details.")
        sys.exit(1)
    except Exception as e:
        print(f"\nFatal error: {e}")
        sys.exit(1)