import io
import os

from flask import Flask, jsonify, render_template, request, send_file

from handbook.generator import generate_handbook

app = Flask(__name__)


@app.route("/")
def index():
    return render_template("index.html")


@app.route("/api/generate", methods=["POST"])
def api_generate():
    data = request.get_json(silent=True) or {}
    topic = (data.get("topic") or "").strip()
    if not topic:
        return jsonify({"error": "主题不能为空"}), 400

    try:
        markdown = generate_handbook(topic)
    except Exception as exc:  # noqa: BLE001
        return jsonify({"error": f"生成失败: {exc}"}), 500

    return jsonify({"topic": topic, "markdown": markdown})


@app.route("/api/export", methods=["POST"])
def api_export():
    data = request.get_json(silent=True) or {}
    topic = (data.get("topic") or "handbook").strip() or "handbook"
    markdown = data.get("markdown") or ""

    if not markdown:
        return jsonify({"error": "内容不能为空"}), 400

    buffer = io.BytesIO(markdown.encode("utf-8"))
    buffer.seek(0)
    safe_name = "".join(c for c in topic if c.isalnum() or c in "-_ ").strip() or "handbook"
    return send_file(
        buffer,
        mimetype="text/markdown",
        as_attachment=True,
        download_name=f"{safe_name}-登记手册.md",
    )


if __name__ == "__main__":
    port = int(os.environ.get("PORT", "5000"))
    app.run(host="0.0.0.0", port=port, debug=True)