#!/usr/bin/env python3
"""
Scribus headless export script.
Called via: scribus -g -ns -py export_document.py -- [args]

Exports a .sla template to PDF or PNG, optionally substituting variables.
"""

import sys
import os

# Parse args after '--' separator
def parse_args():
    args = {}
    variables = {}
    argv = sys.argv[1:]  # Scribus passes script args after '--'
    i = 0
    while i < len(argv):
        if argv[i] == "--input" and i + 1 < len(argv):
            args["input"] = argv[i + 1]
            i += 2
        elif argv[i] == "--output" and i + 1 < len(argv):
            args["output"] = argv[i + 1]
            i += 2
        elif argv[i] == "--format" and i + 1 < len(argv):
            args["format"] = argv[i + 1]
            i += 2
        elif argv[i] == "--dpi" and i + 1 < len(argv):
            args["dpi"] = int(argv[i + 1])
            i += 2
        elif argv[i] == "--var" and i + 1 < len(argv):
            key, _, value = argv[i + 1].partition("=")
            variables[key] = value
            i += 2
        else:
            i += 1
    args["variables"] = variables
    return args


def main():
    try:
        import scribus
    except ImportError:
        print("ERROR: This script must be run inside Scribus (scribus -g -py)")
        sys.exit(1)

    args = parse_args()
    input_file = args.get("input")
    output_file = args.get("output")
    fmt = args.get("format", "pdf")
    dpi = args.get("dpi", 300)
    variables = args.get("variables", {})

    if not input_file or not output_file:
        print("ERROR: --input and --output required")
        sys.exit(1)

    # Open the document
    try:
        scribus.openDoc(input_file)
    except Exception as e:
        print(f"ERROR: Could not open {input_file}: {e}")
        sys.exit(1)

    # Substitute variables in text frames
    if variables:
        page_count = scribus.pageCount()
        for page_num in range(1, page_count + 1):
            scribus.gotoPage(page_num)
            items = scribus.getPageItems()
            for item_name, item_type, _ in items:
                # item_type 4 = text frame
                if item_type == 4:
                    try:
                        text = scribus.getText(item_name)
                        modified = False
                        for key, value in variables.items():
                            placeholder = f"%{key}%"
                            if placeholder in text:
                                text = text.replace(placeholder, value)
                                modified = True
                        if modified:
                            scribus.selectText(0, scribus.getTextLength(item_name), item_name)
                            scribus.deleteText(item_name)
                            scribus.insertText(text, 0, item_name)
                    except Exception:
                        continue

    # Export
    if fmt == "pdf":
        pdf = scribus.PDFfile()
        pdf.file = output_file
        pdf.quality = 0  # Maximum quality
        pdf.resolution = dpi
        pdf.version = 14  # PDF 1.4
        pdf.compress = True
        pdf.compressmtd = 0  # Automatic
        pdf.save()
    elif fmt == "png":
        # Export each page as PNG
        scribus.savePageAsEPS(output_file.replace(".png", ".eps"))
        # Note: for PNG, we rely on post-processing with ghostscript/imagemagick
        print(f"EPS exported to {output_file.replace('.png', '.eps')}")
        print("Convert with: convert -density {dpi} file.eps file.png")
    elif fmt == "svg":
        # Scribus can export to SVG
        scribus.saveDoc()

    scribus.closeDoc()
    print(f"Exported: {output_file}")


if __name__ == "__main__":
    main()