#!/usr/bin/env python3
"""Convert an exported chat history JSON into one markdown file per conversation.

Usage:
    python3 chat_export_to_md.py conversations.json ./raw --min-words 150

Works with the common export shape used by Claude and ChatGPT: a JSON array of
conversations, each with a name/title and a list of messages. Unknown shapes are
skipped with a warning rather than guessed at.

Read the privacy page before running this on a real export. Chat history is the
single most sensitive thing most people would put in a vault.
"""
import argparse
import json
import os
import re
import sys


def slug(text, limit=60):
    s = re.sub(r"[^\w\s-]", "", text.lower()).strip()
    s = re.sub(r"[\s_]+", "-", s)
    return (s[:limit] or "untitled").strip("-")


def text_of(message):
    content = message.get("content", message.get("text", ""))
    if isinstance(content, str):
        return content
    if isinstance(content, list):
        parts = []
        for c in content:
            if isinstance(c, str):
                parts.append(c)
            elif isinstance(c, dict):
                parts.append(c.get("text", ""))
        return "\n".join(p for p in parts if p)
    if isinstance(content, dict):
        return "\n".join(content.get("parts", []) or [])
    return ""


def main():
    ap = argparse.ArgumentParser()
    ap.add_argument("export")
    ap.add_argument("outdir")
    ap.add_argument("--min-words", type=int, default=150,
                    help="skip conversations shorter than this")
    args = ap.parse_args()

    with open(args.export, encoding="utf-8") as fh:
        data = json.load(fh)

    if isinstance(data, dict):
        data = data.get("conversations", [])
    if not isinstance(data, list):
        sys.exit("unrecognised export shape: expected a list of conversations")

    os.makedirs(args.outdir, exist_ok=True)
    written = skipped = 0

    for conv in data:
        if not isinstance(conv, dict):
            continue
        title = conv.get("name") or conv.get("title") or "untitled"
        created = (conv.get("created_at") or conv.get("create_time") or "")
        messages = conv.get("chat_messages") or conv.get("messages") or []
        if isinstance(messages, dict):
            messages = list(messages.values())

        body = []
        for m in messages:
            if not isinstance(m, dict):
                continue
            role = m.get("sender") or m.get("role") or "unknown"
            t = text_of(m).strip()
            if t:
                body.append(f"**{role}**\n\n{t}\n")

        joined = "\n".join(body)
        if len(joined.split()) < args.min_words:
            skipped += 1
            continue

        front = (f"---\ntitle: {title}\nsource: chat export\n"
                 f"created: {str(created)[:10]}\n---\n\n# {title}\n\n")
        path = os.path.join(args.outdir, f"{slug(str(title))}.md")
        n = 2
        while os.path.exists(path):
            path = os.path.join(args.outdir, f"{slug(str(title))}-{n}.md")
            n += 1
        with open(path, "w", encoding="utf-8") as fh:
            fh.write(front + joined)
        written += 1

    print(f"wrote {written} files to {args.outdir}, skipped {skipped} short conversations")


if __name__ == "__main__":
    main()