# -----------------------------------------------------------------------------
# Author: Marina
# Date: 2024-11-15
# -----------------------------------------------------------------------------
"""Script to segment IMO shortlist md files using regex. It takes as input
the file en-compendium.md in en-shortlist and outputs the segmentation
(problem/solution pairs) in en-shortlist-seg
To run:
`python segment_compendium.py`
To debug (or see covered use cases by regex):
`pytest test_segment_compendium`
"""

import json
import os
from pathlib import Path
import re
import pandas as pd


base = "en-shortlist"
seg_base = "en-shortlist-seg"
basename = "en-compendium"


level1_re = re.compile(r"^##\s+(Problems|Solutions|Notation and Abbreviations)$")
year_re = re.compile(r"^[^=]*,\s+(\d{4})\s*$")
problem_section_re = re.compile(r"^###\s+(\d+\.\d+\.\d+)\s+(.+)$")
solution_section_re = re.compile(r"^###\s+(\d+\.\d+)\s+([\w\s]+)\s+(\d{4})$")
problem_or_solution_re = re.compile(r"^(?:\[.*?\])?\s*(\d+)\s*\.\s*(.+)$")


def add_content(current_dict):
    required_keys = ["year", "category", "section_label", "label", "lines"]
    if not all(current_dict[key] for key in required_keys):
        return
    text_str = " ".join(current_dict["lines"]).strip()
    entry = {
        "year": current_dict["year"],
        "category": current_dict["category"],
        "section": current_dict["section_label"],
        "label": current_dict["label"],
    }
    if current_dict["class"] == "problem":
        entry["problem"] = text_str
        current_dict["problems"].append(entry)
    elif current_dict["class"] == "solution":
        entry["solution"] = text_str
        current_dict["solutions"].append(entry)


def get_category(s: str):
    cat = None
    if "contest" in s.lower():
        cat = "contest"
    elif "shortlisted" in s.lower():
        cat = "shortlisted"
    elif "longlisted" in s.lower():
        cat = "longlisted"
    return cat


def get_matching_section_label(s: str):
    """
    extracts the section number to be used a a join key to pair a problem and solution
    for problems: 3.44.1 -> 44
    for solutions: 4.20 -> 20
    """
    return s.split(".")[1]


def parse(file):
    with open(file, "r", encoding="utf-8") as file:
        content = file.read()
    # problems, solutions = [], []
    current = {
        "year": None,
        "category": None,
        "section_label": None,
        "label": None,
        "class": None,
        "lines": [],
        "problems": [],
        "solutions": [],
    }
    for line in content.splitlines():
        if match := level1_re.match(line):
            add_content(current)
            (title,) = match.groups()
            current["class"] = {
                "Problems": "problem",
                "Solutions": "solution",
            }.get(title, "other")
            current["lines"] = []
        elif match := year_re.match(line):
            add_content(current)
            current["year"] = match.group(1)
            current["lines"] = []
        elif match := problem_section_re.match(line):
            add_content(current)
            number, title = match.groups()
            current["section_label"] = get_matching_section_label(number)
            current["category"] = get_category(title)
            current["lines"] = []
        elif match := solution_section_re.match(line):
            add_content(current)
            number, title, year = match.groups()
            current["section_label"] = get_matching_section_label(number)
            current["category"] = get_category(title)
            current["year"] = year
            current["lines"] = []
        elif match := problem_or_solution_re.match(line):
            add_content(current)
            current["label"] = match.group(1)
            current["lines"] = [line]
        else:
            if current["lines"]:
                current["lines"].append(line)
    problems_df = pd.DataFrame(current["problems"])
    solutions_df = pd.DataFrame(current["solutions"])
    return problems_df, solutions_df


def join(problems_df, solutions_df):
    pairs_df = problems_df.merge(
        solutions_df, on=["year", "category", "section", "label"], how="outer"
    )
    return pairs_df


def add_metadata(pairs_df, resource_path):
    problem_type_mapping = {
        "A": "Algebra",
        "C": "Combinatorics",
        "G": "Geometry",
        "N": "Number Theory",
    }
    pairs_df["problem_type"] = pairs_df["problem"].str.extract(r"^\d+\.\s*([ACGN])\d*")[
        0
    ]
    pairs_df["problem_type"] = pairs_df["problem_type"].map(problem_type_mapping)
    pairs_df["tier"] = "T0"  # according to omnimath
    pairs_df["exam"] = "IMO"
    pairs_df["metadata"] = [{"resource_path": resource_path}] * len(pairs_df)
    pairs_df.rename(
        columns={"category": "problem_phase", "label": "problem_label"},
        inplace=True,
    )
    # pairs_df = pairs_df.drop(columns=["section", "label"])
    return pairs_df[
        [
            "year",
            "tier",
            "problem_label",
            "problem_type",
            "exam",
            "problem",
            "solution",
            "metadata",
        ]
    ]


def write_pairs(file_path, pairs_df):
    pairs_df = pairs_df.replace({pd.NA: None, pd.NaT: None, float("nan"): None})
    pairs_dict = pairs_df.to_dict(orient="records")
    output_text = ""
    for pair in pairs_dict:
        output_text += json.dumps(pair, ensure_ascii=False) + "\n"
    file_path.write_text(output_text, encoding="utf-8")


if __name__ == "__main__":
    project_root = Path(__file__).parent.parent.parent
    compet_base_path = Path(__file__).resolve().parent.parent
    compet_md_path = compet_base_path / "md"
    seg_output_path = compet_base_path / "segmented"

    for md_file in compet_md_path.glob("**/*.md"):
        if "compendium" in md_file.name:
            output_file = seg_output_path / md_file.relative_to(
                compet_md_path
            ).with_suffix(".jsonl")
            output_file.parent.mkdir(parents=True, exist_ok=True)

            problems, solutions = parse(md_file)
            pairs_df = join(problems, solutions)
            pairs_df = pairs_df[pairs_df.notnull().all(axis=1)]
            pairs_df = add_metadata(
                pairs_df, output_file.relative_to(project_root).as_posix()
            )
            write_pairs(output_file, pairs_df)

# problems contains duplicate problems (since problem in Shortlist appears in Contest, and problem in Longlist appeasr in Shortlist)
# >>>print(len(problems))
# 2460
# >>>print(len(solutions))
# 961
# print(len(pairs_df))
# 960