#! /usr/bin/env python3

import sys
import os
import re
import yaml
from PIL import Image

document_match = re.compile(r'^--- *$', flags=re.MULTILINE)
fix_tabs = re.compile(r'\t')
fix_initial = re.compile(r'^---\n')


def main():
    if len(sys.argv) < 2:
        sys.exit("Usage: get_yaml_from_example.py yaml_directory png_directory")
    dirname = sys.argv[1]
    if not os.path.isdir(dirname):
        sys.exit("Directory " + str(dirname) + " not found")
    pngdirname = sys.argv[2]
    if not os.path.isdir(pngdirname):
        sys.exit("Directory " + str(pngdirname) + " not found")
    output = {}
    for filename in os.listdir(dirname):
        if not re.search(r'.ya*ml$', filename, flags=re.IGNORECASE):
            continue
        if re.search(r'\#', filename):
            continue
        example_name = os.path.splitext(filename)[0]
        result = {}
        result['yaml'] = read_file(os.path.join(dirname, filename))
        if result['yaml'] is None:
            sys.stderr.write("Missing YAML filename " + os.path.join(dirname, filename) + "\n")
            continue
        png_filename = os.path.join(pngdirname, re.sub(r'\.yml$', '.png', filename))
        if os.path.isfile(png_filename):
            image = Image.open(png_filename)
            (result['width'], result['height']) = image.size
        output[example_name] = result
    print(yaml.safe_dump(output, default_flow_style=False, default_style='|'))


def read_file(filename):
    start_block = 1
    end_block = 2
    if not os.path.isfile(filename):
        sys.exit("File " + str(filename) + " not found")
    with open(filename, 'r', encoding='utf-8') as fp:
        content = fp.read()
        content = fix_tabs.sub('  ', content)
        content = fix_initial.sub('', content)
        blocks = list(map(lambda x: x.strip(), document_match.split(content)))
        if len(blocks) == 0:
            sys.stderr.write("File " + str(filename) + " could not be read\n")
            return None
        metadata = {}
        for the_block in blocks:
            if re.search(r'metadata:', the_block):
                block_info = yaml.load(the_block, Loader=yaml.FullLoader)
                if 'metadata' in block_info:
                    metadata.update(block_info['metadata'])
        start_block = int(metadata.get('example start', 1))
        end_block = int(metadata.get('example end', start_block)) + 1
        result = "\n---\n".join(blocks[start_block:end_block])
    return result

if __name__ == "__main__":
    main()
    sys.exit(None)