"""Flask entrypoint for Busbar Designer.

Serves the static frontend, the /api/export/<fmt> CAD endpoints (build123d →
STEP/DXF/SVG), and the /api/projects, /api/presets, /api/snapshots persistence
endpoints (SQLite via storage.py).

Run:
    python app.py
"""

from __future__ import annotations

import os
import sys
import traceback

from flask import Flask, Response, jsonify, request, send_from_directory

from busbar_export import WRITERS
import storage

APP_DIR = os.path.dirname(os.path.abspath(__file__))
STATIC_DIR = os.path.join(APP_DIR, "static")

app = Flask(__name__, static_folder=STATIC_DIR, static_url_path="")

storage.init_db()


# ---------------------------------------------------------------------------
# Static + health
# ---------------------------------------------------------------------------


@app.get("/")
def index():
    return send_from_directory(STATIC_DIR, "index.html")


@app.get("/api/health")
def health():
    return jsonify({"status": "ok"})


# ---------------------------------------------------------------------------
# CAD export (unchanged contract)
# ---------------------------------------------------------------------------


@app.post("/api/export/<fmt>")
def export(fmt: str):
    fmt = fmt.lower()
    if fmt not in WRITERS:
        return jsonify({"error": f"unsupported format: {fmt}"}), 400

    payload = request.get_json(silent=True) or {}
    writer, mimetype, ext = WRITERS[fmt]
    try:
        data = writer(payload)
    except ValueError as e:
        return jsonify({"error": str(e)}), 400
    except Exception as e:
        traceback.print_exc()
        return jsonify({"error": f"{type(e).__name__}: {e}"}), 500

    filename = f"busbars.{ext}"
    return Response(
        data,
        mimetype=mimetype,
        headers={"Content-Disposition": f'attachment; filename="{filename}"'},
    )


# ---------------------------------------------------------------------------
# Projects
# ---------------------------------------------------------------------------


@app.get("/api/projects")
def projects_index():
    return jsonify(storage.list_projects())


@app.post("/api/projects")
def projects_create():
    body = request.get_json(silent=True) or {}
    name = (body.get("name") or "Untitled").strip() or "Untitled"
    data = body.get("data") or {}
    pid = storage.create_project(name, data)
    return jsonify({"id": pid, "name": name})


@app.get("/api/projects/<int:pid>")
def projects_show(pid: int):
    p = storage.get_project(pid)
    if p is None:
        return jsonify({"error": "not found"}), 404
    return jsonify(p)


@app.put("/api/projects/<int:pid>")
def projects_update(pid: int):
    body = request.get_json(silent=True) or {}
    ok = storage.update_project(
        pid,
        name=body.get("name"),
        data=body.get("data"),
        snapshot=bool(body.get("snapshot", False)),
        note=body.get("note"),
    )
    if not ok:
        return jsonify({"error": "not found"}), 404
    return jsonify({"ok": True})


@app.delete("/api/projects/<int:pid>")
def projects_delete(pid: int):
    storage.delete_project(pid)
    return jsonify({"ok": True})


# ---------------------------------------------------------------------------
# Snapshots
# ---------------------------------------------------------------------------


@app.get("/api/projects/<int:pid>/snapshots")
def snapshots_index(pid: int):
    return jsonify(storage.list_snapshots(pid))


@app.get("/api/snapshots/<int:sid>")
def snapshot_show(sid: int):
    snap = storage.get_snapshot(sid)
    if snap is None:
        return jsonify({"error": "not found"}), 404
    return jsonify(snap)


@app.post("/api/snapshots/<int:sid>/restore")
def snapshot_restore(sid: int):
    if not storage.restore_snapshot(sid):
        return jsonify({"error": "not found"}), 404
    return jsonify({"ok": True})


# ---------------------------------------------------------------------------
# Presets
# ---------------------------------------------------------------------------


@app.get("/api/presets")
def presets_index():
    return jsonify(storage.list_presets())


@app.post("/api/presets")
def presets_create():
    body = request.get_json(silent=True) or {}
    name = (body.get("name") or "").strip()
    if not name:
        return jsonify({"error": "name required"}), 400
    pid = storage.create_preset(name, body.get("params") or {})
    if pid is None:
        return jsonify({"error": "name already in use"}), 409
    return jsonify({"id": pid, "name": name})


@app.put("/api/presets/<int:pid>")
def presets_update(pid: int):
    body = request.get_json(silent=True) or {}
    ok = storage.update_preset(pid, name=body.get("name"), params=body.get("params"))
    if not ok:
        return jsonify({"error": "not found or name conflict"}), 404
    return jsonify({"ok": True})


@app.delete("/api/presets/<int:pid>")
def presets_delete(pid: int):
    storage.delete_preset(pid)
    return jsonify({"ok": True})


# ---------------------------------------------------------------------------
# Boot
# ---------------------------------------------------------------------------


if __name__ == "__main__":
    port = int(os.environ.get("PORT", 5000))
    host = os.environ.get("HOST", "127.0.0.1")
    debug = os.environ.get("FLASK_DEBUG", "1") == "1"
    print(f" * Busbar Designer running on http://{host}:{port}", file=sys.stderr)
    app.run(host=host, port=port, debug=debug)