import os
import glob
import json

import datasets


class JourneyBeyond(datasets.GeneratorBasedBuilder):
    """Dataset for '432: A Journey Beyond' with structured sections."""

    VERSION = datasets.Version("1.0.0")

    def _info(self):
        features = datasets.Features(
            {
                "section": datasets.Value("string"),
                "title": datasets.Value("string"),
                "text": datasets.Value("string"),
            }
        )
        return datasets.DatasetInfo(
            description="A structured dataset from the book '432: A Journey Beyond', organized by sections with text content from individual files.",
            features=features,
            homepage="https://huggingface.co/datasets/paulolden1/432-a-journey-beyond",
        )

    def _split_generators(self, dl_manager):
        # When loaded from HF, the script's directory is the root of the cloned repo.
        data_dir = os.path.dirname(__file__)
        return [
            datasets.SplitGenerator(
                name=datasets.Split.TRAIN,
                gen_kwargs={"data_dir": data_dir},
            ),
        ]

    def _generate_examples(self, data_dir):
        idx = 0
        sections = ["frontmatter", "chapters", "backmatter", "supplementary"]
        
        for section in sections:
            section_path = os.path.join(data_dir, section)
            if not os.path.exists(section_path):
                continue
            
            # Sort files alphabetically to maintain chapter/interlude order
            file_paths = sorted(glob.glob(os.path.join(section_path, "*.*")))
            
            for file_path in file_paths:
                ext = os.path.splitext(file_path)[1].lower()
                if ext not in (".txt", ".md", ".json"):
                    continue  # Skip unsupported files
                
                try:
                    with open(file_path, "r", encoding="utf-8") as f:
                        if ext == ".json":
                            data = json.load(f)
                            text = json.dumps(data, indent=2)  # Stringify JSON for text feature
                        else:
                            text = f.read().strip()
                    
                    # Derive title from filename (e.g., 'chapter_01.txt' -> 'Chapter 01')
                    filename = os.path.basename(file_path)
                    title = os.path.splitext(filename)[0].replace("_", " ").title()
                    
                    yield idx, {
                        "section": section,
                        "title": title,
                        "text": text,
                    }
                    idx += 1
                except Exception as e:
                    # Skip problematic files silently
                    pass