"""Engineer image > Engineering Layer tab: upload the Engineering Layer
installer (or the whole extra_engineering payload) the engineer unattend
installs. Logic in services/engineering_layer.py."""

from flask import Blueprint, flash, jsonify, redirect, render_template, request, url_for

import config
from services import engineering_layer as el
from services.audit import audit

bp = Blueprint("engineering_layer", __name__, url_prefix="/images")


def _back():
    return redirect(url_for("engineering_layer.page", image_type=el.IMAGE))


@bp.route("/<image_type>/engineering-layer")
def page(image_type):
    if image_type != el.IMAGE:
        flash("The Engineering Layer belongs to the engineer image.", "warning")
        return redirect(url_for("images.overview", image_type=image_type)) \
            if image_type in config.IMAGE_TYPES else redirect(url_for("dashboard"))
    return render_template(
        "image_engineering_layer.html",
        image_type=image_type,
        friendly_name=config.FRIENDLY_NAMES.get(image_type, image_type),
        active_tab="englayer",
        st=el.status(),
    )


@bp.route("/gea-engineer/engineering-layer/upload", methods=["POST"])
def upload():
    """Raw body (the page's XHR upload, name in ?name=) streams to disk."""
    name = request.args.get("name", "")
    try:
        res = el.upload(request.stream, name, request.content_length)
    except (ValueError, RuntimeError, OSError) as ex:
        return jsonify({"ok": False, "error": str(ex)}), 400
    audit("ENGINEERING_LAYER_UPLOAD",
          f"{res['name']} ({res['size']} bytes): replaced {', '.join(res['replaced'])}; "
          f"installer v{res['version']}; previous in archive {res['archived'] or '(none)'}")
    flash(f"Engineering Layer updated from {res['name']}: installer v{res['version']}"
          + (f", previous kept as {res['archived']}." if res["archived"] else "."), "success")
    return jsonify({"ok": True, **res})


@bp.route("/gea-engineer/engineering-layer/restore/<stamp>", methods=["POST"])
def restore(stamp):
    try:
        parts = el.restore(stamp)
    except (ValueError, RuntimeError, OSError) as ex:
        flash(f"Not restored: {ex}", "danger")
        return _back()
    audit("ENGINEERING_LAYER_RESTORE", f"{stamp}: {', '.join(parts)}")
    flash(f"Restored the Engineering Layer from {stamp}; the replaced one is archived.", "success")
    return _back()