// src/index.js - Updated Image Upload Worker with AI Vision Validation
// Features:
// 1. AI Vision validation (is this a property photo?)
// 2. Get image name from AIDA
// 3. Handle add/replace operations
// 4. Duplicate name numbering

export default {
  async fetch(request, env) {
    // CORS preflight
    if (request.method === "OPTIONS") {
      return new Response(null, {
        status: 204,
        headers: {
          "Access-Control-Allow-Origin": "*",
          "Access-Control-Allow-Methods": "POST, OPTIONS",
          "Access-Control-Allow-Headers": "*"
        }
      });
    }

    if (request.method !== "POST") {
      return new Response("Only POST allowed", {
        status: 405,
        headers: { "Access-Control-Allow-Origin": "*" }
      });
    }

    const contentType = request.headers.get("Content-Type") || "";
    if (!contentType.includes("multipart/form-data")) {
      return new Response("Unsupported Media Type", {
        status: 415,
        headers: { "Access-Control-Allow-Origin": "*" }
      });
    }

    const contentLength = request.headers.get("content-length");
    if (contentLength && parseInt(contentLength) > 5 * 1024 * 1024) {
      return new Response("Image too large. Max 5MB.", {
        status: 400,
        headers: { "Access-Control-Allow-Origin": "*" }
      });
    }

    // Configuration - MOVE THESE TO ENVIRONMENT VARIABLES IN PRODUCTION
    const ACCOUNT_ID = env.CF_ACCOUNT_ID || "375f7ecab9677eb4e6362cbed2e09358";
    const API_TOKEN = env.CF_API_TOKEN || "Kyx_WSRHASBktvx6GbI5W-HRxPiBuO6J867uegXw";
    const ACCOUNT_HASH = env.CF_ACCOUNT_HASH || "0utJlkqgAVuawL5OpMWxgw";
    const AIDA_BASE_URL = env.AIDA_BASE_URL || "https://destinyebuka-aida.hf.space";

    try {
      // Parse form data
      const formData = await request.formData();
      const imageFile = formData.get("file");
      const userMessage = formData.get("message") || "";
      const userId = formData.get("user_id") || "";
      const sessionId = formData.get("session_id") || "";
      const operation = formData.get("operation") || "add"; // "add" or "replace"
      const replaceIndex = formData.get("replace_index"); // For replace operations
      const existingImageId = formData.get("existing_image_id"); // ID of image to replace

      if (!imageFile) {
        return jsonResponse({ success: false, error: "no_image", message: "No image file provided" }, 400);
      }

      // Convert image to bytes for AI validation
      const imageBytes = await imageFile.arrayBuffer();
      const imageArray = [...new Uint8Array(imageBytes)];

      // ============================================================
      // STEP 1: AI Vision Validation
      // ============================================================
      let isPropertyImage = false;
      let validationReason = "";

      try {
        const aiResult = await env.AI.run('@cf/llava-hf/llava-1.5-7b-hf', {
          image: imageArray,
          prompt: "Is this image showing a real estate property such as a house, apartment, room, building, or property exterior/interior? Answer with ONLY 'YES' or 'NO' followed by a brief reason.",
          max_tokens: 50
        });

        const response = aiResult.description || aiResult.response || String(aiResult);
        isPropertyImage = response.toUpperCase().includes("YES");
        validationReason = response;

      } catch (aiError) {
        // If AI fails, allow the image through (fail-open for better UX)
        console.error("AI validation error:", aiError);
        isPropertyImage = true;
        validationReason = "AI validation skipped due to error";
      }

      // If not a property image, return error (AIDA will handle friendly message)
      if (!isPropertyImage) {
        return jsonResponse({
          success: false,
          error: "not_property_image",
          reason: validationReason,
          message: userMessage,
          user_id: userId,
          session_id: sessionId
        }, 400);
      }

      // ============================================================
      // STEP 2: Get Image Name from AIDA (if new image)
      // ============================================================
      let imageName = "";

      if (operation === "add") {
        try {
          const nameResponse = await fetch(`${AIDA_BASE_URL}/ai/get-image-name`, {
            method: "POST",
            headers: { "Content-Type": "application/json" },
            body: JSON.stringify({
              user_id: userId,
              session_id: sessionId
            })
          });

          if (nameResponse.ok) {
            const nameData = await nameResponse.json();
            imageName = nameData.name || `property-${Date.now()}`;
          } else {
            imageName = `property-${Date.now()}`;
          }
        } catch (nameError) {
          console.error("Failed to get image name from AIDA:", nameError);
          imageName = `property-${Date.now()}`;
        }
      }

      // ============================================================
      // STEP 3: Handle Replace Operation (delete old image)
      // ============================================================
      if (operation === "replace" && existingImageId) {
        try {
          // Get existing image name before deleting
          const listResponse = await fetch(
            `https://api.cloudflare.com/client/v4/accounts/${ACCOUNT_ID}/images/v1/${existingImageId}`,
            {
              method: "GET",
              headers: { Authorization: `Bearer ${API_TOKEN}` }
            }
          );

          if (listResponse.ok) {
            const existingData = await listResponse.json();
            if (existingData.result?.filename) {
              imageName = existingData.result.filename.replace(/\.[^/.]+$/, ""); // Remove extension
            }
          }

          // Delete old image
          await fetch(
            `https://api.cloudflare.com/client/v4/accounts/${ACCOUNT_ID}/images/v1/${existingImageId}`,
            {
              method: "DELETE",
              headers: { Authorization: `Bearer ${API_TOKEN}` }
            }
          );
        } catch (deleteError) {
          console.error("Failed to delete old image:", deleteError);
          // Continue with upload anyway
        }
      }

      // ============================================================
      // STEP 4: Upload to Cloudflare Images
      // ============================================================
      
      // Clean the image name for use as filename
      const cleanName = imageName
        .toLowerCase()
        .replace(/[^a-z0-9]+/g, '-')
        .replace(/^-|-$/g, '')
        || `property-${Date.now()}`;

      // Create new FormData for Cloudflare upload
      const uploadFormData = new FormData();
      uploadFormData.append("file", new Blob([imageBytes], { type: imageFile.type }), `${cleanName}.jpg`);

      const cloudflareUploadURL = `https://api.cloudflare.com/client/v4/accounts/${ACCOUNT_ID}/images/v1`;
      const uploadResponse = await fetch(cloudflareUploadURL, {
        method: "POST",
        headers: { Authorization: `Bearer ${API_TOKEN}` },
        body: uploadFormData
      });

      const uploadResponseBody = await uploadResponse.json();

      if (uploadResponse.ok && uploadResponseBody.success && uploadResponseBody.result) {
        const imageId = uploadResponseBody.result.id;
        const imageUrl = `https://imagedelivery.net/${ACCOUNT_HASH}/${imageId}/public`;

        // Return success with all context for AIDA
        return jsonResponse({
          success: true,
          id: imageId,
          url: imageUrl,
          filename: cleanName,
          message: userMessage,
          operation: operation,
          replace_index: replaceIndex,
          user_id: userId,
          session_id: sessionId
        }, 200);

      } else {
        const errorDetails = uploadResponseBody.errors || [];
        return jsonResponse({
          success: false,
          error: "upload_failed",
          details: errorDetails,
          message: userMessage,
          user_id: userId,
          session_id: sessionId
        }, uploadResponse.status);
      }

    } catch (error) {
      console.error("Worker error:", error);
      return jsonResponse({
        success: false,
        error: "worker_error",
        details: error.message
      }, 500);
    }
  }
};

// Helper function for JSON responses
function jsonResponse(data, status) {
  return new Response(JSON.stringify(data), {
    status,
    headers: {
      "Content-Type": "application/json",
      "Access-Control-Allow-Origin": "*"
    }
  });
}