server.ts

import express from "express";
import path from "path";
import { createServer as createViteServer } from "vite";
import { GoogleGenAI, Type } from "@google/genai";
import dotenv from "dotenv";

dotenv.config();

// Initialize Express
const app = express();
app.use(express.json());

const PORT = 3000;

// Lazy initialize Gemini API client
let aiClient: GoogleGenAI | null = null;
function getAiClient(): GoogleGenAI {
  if (!aiClient) {
    const apiKey = process.env.GEMINI_API_KEY;
    if (!apiKey) {
      throw new Error("GEMINI_API_KEY environment variable is not set.");
    }
    aiClient = new GoogleGenAI({
      apiKey,
      httpOptions: {
        headers: {
          "User-Agent": "aistudio-build",
        },
      },
    });
  }
  return aiClient;
}

// AI Issue Triage Endpoint
app.post("/api/triage", async (req, res) => {
  try {
    const { complaint, assetName, assetCategory, assetLocation, assetCondition, recentHistory } = req.body;

    if (!complaint) {
      return res.status(400).json({ error: "Complaint text is required" });
    }

    let ai;
    try {
      ai = getAiClient();
    } catch (e: any) {
      // API key is missing or not configured
      console.warn("Gemini Client initialization failed, returning fallback data:", e.message);
      return res.json({
        title: "Triage Alert: " + (complaint.length > 30 ? complaint.substring(0, 30) + "..." : complaint),
        category: assetCategory || "General",
        priority: "High",
        possibleCauses: ["Requires technician diagnostic due to manual submission"],
        initialChecks: ["Advise visual inspection only", "Ensure area is secure before technician arrival"],
        recurringPatternWarning: recentHistory && recentHistory.length > 0 ? "Warning: Asset has a history of reported issues." : "",
        isFallback: true,
        errorMessage: "GEMINI_API_KEY is not configured in Secrets."
      });
    }

    const prompt = `
      Please triage this maintenance issue.
      
      Asset Name: ${assetName || "Unknown Asset"}
      Asset Category: ${assetCategory || "Unknown Category"}
      Asset Location: ${assetLocation || "Unknown Location"}
      Asset Condition: ${assetCondition || "Unknown"}
      Recent History: ${recentHistory && recentHistory.length > 0 ? JSON.stringify(recentHistory) : "No recent issues reported"}
      
      User Complaint: "${complaint}"
    `;

    const systemInstruction = `
      You are MaintainIQ's expert AI maintenance engineer. Convert the user's natural-language complaint and asset context into a structured JSON triage report.
      Ensure you do NOT provide unsafe instructions for electrical, mechanical, fire, medical, or industrial hazards. Always clearly recommend qualified technicians for critical or safety-related issues.
      Analyse the recent history (if any) to check for repeated patterns (e.g. if the AC had the same leak 2 weeks ago, warn about a recurring drain blockage).
    `;

    const response = await ai.models.generateContent({
      model: "gemini-3.5-flash",
      contents: prompt,
      config: {
        systemInstruction,
        responseMimeType: "application/json",
        responseSchema: {
          type: Type.OBJECT,
          properties: {
            title: {
              type: Type.STRING,
              description: "A concise professional title describing the issue."
            },
            category: {
              type: Type.STRING,
              description: "The suggested category of the issue (e.g. Electrical, Plumbing, HVAC, Mechanical, IT Hardware, Structural, etc.)."
            },
            priority: {
              type: Type.STRING,
              description: "Suggested priority: Low, Medium, High, or Critical."
            },
            possibleCauses: {
              type: Type.ARRAY,
              items: { type: Type.STRING },
              description: "A list of 2-4 possible root causes."
            },
            initialChecks: {
              type: Type.ARRAY,
              items: { type: Type.STRING },
              description: "A list of 2-4 safe initial checks for the user or technician. For any hazardous system, advise calling a qualified professional."
            },
            recurringPatternWarning: {
              type: Type.STRING,
              description: "A warning message summarizing any repeated patterns found in history, or an empty string if none."
            }
          },
          required: ["title", "category", "priority", "possibleCauses", "initialChecks", "recurringPatternWarning"]
        }
      }
    });

    const text = response.text;
    if (!text) {
      throw new Error("No response text from Gemini API.");
    }

    const parsedResult = JSON.parse(text.trim());
    return res.json(parsedResult);
  } catch (err: any) {
    console.error("AI Triage Error:", err);
    return res.json({
      title: "Diagnostics Required",
      category: "General",
      priority: "Medium",
      possibleCauses: ["Requires manual investigation", "No AI triage results available"],
      initialChecks: ["Safely secure the asset", "Report details to supervisor"],
      recurringPatternWarning: "",
      isFallback: true,
      errorMessage: err.message
    });
  }
});

// Setup Vite or serve static production build
async function startServer() {
  if (process.env.NODE_ENV !== "production") {
    const vite = await createViteServer({
      server: { middlewareMode: true },
      appType: "spa",
    });
    app.use(vite.middlewares);
  } else {
    const distPath = path.join(process.cwd(), "dist");
    app.use(express.static(distPath));
    app.get("*", (req, res) => {
      res.sendFile(path.join(distPath, "index.html"));
    });
  }

  app.listen(PORT, "0.0.0.0", () => {
    console.log(`Server running on http://localhost:${PORT}`);
  });
}

startServer();