#!/usr/bin/env python3
"""
Test different Y offsets to find the correct one.
Creates multiple pages with different offsets.
"""

import json
from pdf2image import convert_from_path
from reportlab.pdfgen import canvas
from reportlab.lib.utils import ImageReader
from reportlab.lib.colors import red, blue
from reportlab.pdfbase import pdfmetrics
from reportlab.pdfbase.ttfonts import TTFont
import tempfile
import os

# Font
try:
    pdfmetrics.registerFont(TTFont('CF', 'C:/Windows/Fonts/msyh.ttc'))
    font = 'CF'
except:
    font = 'Helvetica'

# Load
with open('Raw/DevelopChinese/OCR/听力Intro.json') as f:
    data = json.load(f)

# Convert
imgs = convert_from_path('Raw/DevelopChinese/PDF/听力Intro.pdf', dpi=300, first_page=1, last_page=1)
img = imgs[0]
w, h = img.size
print(f'Image: {w}x{h}')

# Save image once
with tempfile.NamedTemporaryFile(suffix='.png', delete=False) as tmp:
    img.save(tmp.name, 'PNG')
    tmp_path = tmp.name

# Create PDF with multiple test pages
c = canvas.Canvas('test_Y_OFFSETS.pdf')

# Test different Y offsets
test_offsets = [-200, -150, -100, -50, 0, 50, 100, 150, 200]

for offset in test_offsets:
    c.setPageSize((w, h))

    # Draw image
    c.drawImage(ImageReader(tmp_path), 0, 0, width=w, height=h)

    # Draw title
    c.setFont('Helvetica', 20)
    c.setFillColorRGB(1, 0, 0)
    c.drawString(50, h - 50, f'Y OFFSET: {offset:+d} pixels')

    # Draw boxes with offset
    count = 0
    for d in data['pages'][0]['details']:
        text = d.get('text', '').strip()
        if not text or count >= 30:  # Limit to first 30 for clarity
            continue
        bbox = d.get('bbox', [])
        if not bbox or len(bbox) != 4:
            continue

        xs = [p[0] for p in bbox]
        ys = [p[1] for p in bbox]
        x = min(xs)
        width = max(xs) - x

        # Apply offset to Y calculation
        y_base = h - max(ys)
        y = y_base + offset
        height = max(ys) - min(ys)

        c.setStrokeColor(red)
        c.setLineWidth(0.5)
        c.rect(x, y, width, height, stroke=1, fill=0)

        font_size = max(1, height * 0.7)
        c.setFont(font, font_size)
        c.setFillColor(blue)
        c.drawString(x, y, text)

        count += 1

    c.showPage()
    print(f'Page with offset {offset:+d} done')

c.save()
os.unlink(tmp_path)

print(f'\nCreated test_Y_OFFSETS.pdf with {len(test_offsets)} pages')
print('Browse through pages to find which offset aligns boxes correctly!')
print('Offsets tested:', test_offsets)