import json
import pdfplumber
import re

def extract_from_pdf(pdf_path, output_json_path):
    questions = []
    current_q = None
    global_id = 1
    
    with pdfplumber.open(pdf_path) as pdf:
        for page_num, page in enumerate(pdf.pages):
            tables = page.extract_tables()
            for table in tables:
                for row in table:
                    if not row or len(row) < 5:
                        continue
                    
                    col0 = str(row[0]).strip() if row[0] is not None else ""
                    if col0 in ["序号", "序\n号", "序", "号", "题目", "可选项"]:
                        continue
                        
                    is_new_q = False
                    if col0.isdigit():
                        is_new_q = True
                        # q_id = int(col0)
                    
                    title = row[1] if row[1] else ""
                    options_raw = row[2] if row[2] else ""
                    q_type = row[3] if row[3] else ""
                    q_answer = row[4] if row[4] else ""
                    source_file = row[5] if len(row) > 5 and row[5] else ""
                    
                    # Split options
                    opts = re.split(r'(?=[A-H][\.、])', options_raw)
                    parsed_options = [opt.strip().replace('\n', '') for opt in opts if opt.strip()]
                    
                    if is_new_q:
                        if current_q:
                            current_q["id"] = global_id
                            questions.append(current_q)
                            global_id += 1
                        current_q = {
                            "title": title.replace('\n', ''),
                            "options": parsed_options,
                            "type": q_type.replace('\n', '').strip(),
                            "answer": q_answer.replace('\n', '').strip(),
                            "source_id": col0, # keeping original id for reference
                            "page_number": page_num + 1,
                            "source_file": source_file.replace('\n', '').strip()
                        }
                    elif current_q:
                        if title:
                            current_q["title"] += title.replace('\n', '')
                        if parsed_options:
                            current_q["options"].extend(parsed_options)
                        if q_type:
                            current_q["type"] += q_type.replace('\n', '').strip()
                        if q_answer:
                            current_q["answer"] += q_answer.replace('\n', '').strip()
                        if source_file:
                            current_q["source_file"] += source_file.replace('\n', '').strip()

    if current_q:
        current_q["id"] = global_id
        questions.append(current_q)
        
    print(f"Extracted {len(questions)} questions via table parsing.")
    
    bad = [x for x in questions if len(x['options']) < 2]
    print(f"Questions with <2 options: {len(bad)}")
    
    with open(output_json_path, 'w', encoding='utf-8') as f:
        json.dump(questions, f, ensure_ascii=False, indent=2)

if __name__ == "__main__":
    extract_from_pdf("d:/code/bigdata/题库.pdf", "d:/code/bigdata/questions.json")