const fs = require("node:fs/promises");
const path = require("node:path");
const express = require("express");
const NodeHelper = require("node_helper");
const QRCode = require("qrcode");
const NextcloudPublicShare = require("./lib/nextcloud-public-share");
const { parseYield, scaleRecipe } = require("./lib/recipe-scaler");

module.exports = NodeHelper.create({
  start() {
    this.config = { controlPath: "/MMM-NextcloudCookbook/control" };
    this.state = { active: false, recipeId: null, recipe: null, portions: null, error: null };
    this.recipeCache = { expires: 0, recipes: [] };
    this.stateFile = path.join(process.cwd(), "config", "MMM-NextcloudCookbook-state.json");
    this.configureClient();
    this.registerRoutes();
    this.stateReady = this.loadState().catch((error) => this.setError(error));
  },

  socketNotificationReceived(notification, payload) {
    if (notification !== "CONFIG") return;
    this.config = { ...this.config, ...payload };
    try {
      this.configureClient();
    } catch (error) {
      this.setError(error);
      return;
    }
    this.stateReady.then(async () => {
      this.sendSocketNotification("STATE", this.publicState());
      await this.restoreRecipe();
    }).catch((error) => this.setError(error));
  },

  configureClient() {
    const shareUrl = process.env.SECRET_NEXTCLOUD_COOKBOOK_SHARE_URL || this.config.shareUrl;
    const password = process.env.SECRET_NEXTCLOUD_COOKBOOK_SHARE_PASSWORD
      || this.config.sharePassword
      || "";
    this.client = shareUrl
      ? new NextcloudPublicShare({
        shareUrl,
        password
      })
      : null;
    this.recipeCache = { expires: 0, recipes: [] };
  },

  registerRoutes() {
    this.expressApp.use("/MMM-NextcloudCookbook/api", express.json({ limit: "16kb" }));
    this.expressApp.get("/MMM-NextcloudCookbook/control", (_request, response) => {
      response.sendFile(path.join(__dirname, "control", "index.html"));
    });
    this.expressApp.use(
      "/MMM-NextcloudCookbook/assets",
      express.static(path.join(__dirname, "control"))
    );
    this.expressApp.get("/MMM-NextcloudCookbook/qr.svg", async (request, response, next) => {
      try {
        const url = this.config.controlUrl
          || `${request.protocol}://${request.get("host")}${this.config.controlPath}`;
        response.type("image/svg+xml").send(await QRCode.toString(url, { type: "svg", margin: 1 }));
      } catch (error) {
        next(error);
      }
    });
    this.expressApp.get("/MMM-NextcloudCookbook/api/state", (_request, response) => {
      response.json(this.publicState());
    });
    this.expressApp.get("/MMM-NextcloudCookbook/api/recipes", async (_request, response, next) => {
      try {
        response.json(await this.listRecipes());
      } catch (error) {
        next(error);
      }
    });
    this.expressApp.post("/MMM-NextcloudCookbook/api/activate", async (request, response, next) => {
      try {
        const recipeId = request.body?.recipeId;
        if (typeof recipeId !== "string" || !recipeId) {
          return response.status(400).json({ error: "recipeId is required" });
        }
        const recipe = await this.getClient().getRecipe(recipeId);
        this.state = {
          active: true,
          recipeId,
          recipe,
          portions: Math.max(1, Math.round(parseYield(recipe.recipeYield) || 1)),
          error: null
        };
        await this.saveState();
        this.sendSocketNotification("STATE", this.publicState());
        return response.json(this.publicState());
      } catch (error) {
        return next(error);
      }
    });
    this.expressApp.post("/MMM-NextcloudCookbook/api/portions", async (request, response, next) => {
      try {
        const delta = request.body?.delta;
        if (!this.state.active || !this.state.recipe) {
          return response.status(409).json({ error: "No recipe is active" });
        }
        if (delta !== -1 && delta !== 1) {
          return response.status(400).json({ error: "delta must be -1 or 1" });
        }
        this.state.portions = Math.max(1, this.state.portions + delta);
        await this.saveState();
        this.sendSocketNotification("STATE", this.publicState());
        return response.json(this.publicState());
      } catch (error) {
        return next(error);
      }
    });
    this.expressApp.post("/MMM-NextcloudCookbook/api/exit", async (_request, response, next) => {
      try {
        this.state = { active: false, recipeId: null, recipe: null, portions: null, error: null };
        await this.saveState();
        this.sendSocketNotification("STATE", this.publicState());
        response.json(this.publicState());
      } catch (error) {
        next(error);
      }
    });
    this.expressApp.use("/MMM-NextcloudCookbook/api", (error, _request, response, _next) => {
      console.error(`[MMM-NextcloudCookbook] ${error.message}`);
      response.status(error.status || 500).json({ error: error.message || "Recipe request failed" });
    });
  },

  getClient() {
    if (!this.client) throw new Error("Nextcloud Cookbook is not configured yet");
    return this.client;
  },

  async listRecipes() {
    if (Date.now() < this.recipeCache.expires) return this.recipeCache.recipes;
    const recipes = await this.getClient().listRecipes();
    this.recipeCache = { expires: Date.now() + 5 * 60 * 1000, recipes };
    return recipes;
  },

  async loadState() {
    try {
      const persisted = JSON.parse(await fs.readFile(this.stateFile, "utf8"));
      if (!persisted.active || !persisted.recipeId) return;
      this.state = {
        active: true,
        recipeId: persisted.recipeId,
        recipe: null,
        portions: Number.isInteger(persisted.portions) ? persisted.portions : null,
        error: null
      };
    } catch (error) {
      if (error.code !== "ENOENT") throw error;
    }
  },

  async restoreRecipe() {
    if (!this.state.active || !this.state.recipeId) return;
    try {
      this.state.recipe = await this.getClient().getRecipe(this.state.recipeId);
      this.state.portions ||= Math.max(1, Math.round(parseYield(this.state.recipe.recipeYield) || 1));
      this.state.error = null;
    } catch (error) {
      this.setError(error);
    }
    this.sendSocketNotification("STATE", this.publicState());
  },

  async saveState() {
    const temporary = `${this.stateFile}.tmp`;
    await fs.writeFile(temporary, `${JSON.stringify({
      active: this.state.active,
      recipeId: this.state.recipeId,
      portions: this.state.portions
    })}\n`, {
      mode: 0o600
    });
    await fs.rename(temporary, this.stateFile);
  },

  setError(error) {
    this.state.error = error instanceof Error ? error.message : String(error);
    this.sendSocketNotification("STATE", this.publicState());
  },

  publicState() {
    return {
      active: this.state.active,
      recipeId: this.state.recipeId,
      recipe: this.state.recipe ? scaleRecipe(this.state.recipe, this.state.portions) : null,
      portions: this.state.portions,
      error: this.state.error
    };
  }
});