#!/usr/bin/env python3
"""tools/manual/find_pages.py <pass.pdf> <toc.json> <pages.json>: sucht die Seitenzahl jeder Überschrift für das Inhaltsverzeichnis."""
import io
import json
import sys

import pymupdf

pdf, toc_file, out = sys.argv[1], sys.argv[2], sys.argv[3]
toc = json.load(io.open(toc_file, encoding='utf-8'))
doc = pymupdf.open(pdf)
heads = []  # (Seite, Text, Größe)
for pno in range(len(doc)):
    for b in doc[pno].get_text('dict')['blocks']:
        for l in b.get('lines', []):
            txt = ''.join(s['text'] for s in l['spans']).strip()
            size = max((s['size'] for s in l['spans']), default=0)
            if size >= 12 and txt:
                heads.append((pno + 1, txt, size))
pages = {}
cursor = 0
missing = []
for t in toc:
    key = t['title'].strip()
    found = None
    for i in range(cursor, len(heads)):
        p, txt, size = heads[i]
        # Überschrift = "<Nr> <Titel>"; lange Titel brechen um, darum Anfang vergleichen
        flat = txt.replace(' ', ' ')
        if flat.endswith(key) or flat == t['num'] + ' ' + key or key.startswith(flat.split(' ', 1)[-1][:25]) and flat.startswith(t['num'] + ' '):
            if flat.startswith(t['num'] + ' ') or flat.startswith(t['num']):
                found = (i, p)
                break
    if found:
        cursor = found[0] + 1
        pages['k' + t['num'].replace('.', '_')] = found[1]
    else:
        missing.append(t['num'] + ' ' + key)
json.dump(pages, io.open(out, 'w', encoding='utf-8'))
print('gefunden: %d von %d; fehlend: %s' % (len(pages), len(toc), missing[:10]))