import { NextRequest, NextResponse } from "next/server";

/**
 * POST /api/n8n/generate-image
 *
 * Triggers AI image generation for a project via n8n workflow
 *
 * Body:
 * {
 *   projectId: number;
 *   regenerate?: boolean; // Force regenerate even if image exists
 * }
 */
export async function POST(req: NextRequest) {
  try {
    const body = await req.json();
    const { projectId, regenerate = false } = body;

    // Validate input
    if (!projectId) {
      return NextResponse.json(
        { error: "projectId is required" },
        { status: 400 },
      );
    }

    // Check environment variables
    const n8nWebhookUrl = process.env.N8N_WEBHOOK_URL;
    const n8nSecretToken = process.env.N8N_SECRET_TOKEN;

    if (!n8nWebhookUrl) {
      return NextResponse.json(
        {
          error: "N8N_WEBHOOK_URL not configured",
          message:
            "AI image generation is not set up. Please configure n8n webhooks.",
        },
        { status: 503 },
      );
    }

    // Fetch project data first (needed for the new webhook format)
    const projectResponse = await fetch(
      `${process.env.NEXT_PUBLIC_API_URL || "http://localhost:3000"}/api/projects/${projectId}`,
      {
        method: "GET",
        cache: "no-store",
      },
    );

    if (!projectResponse.ok) {
      return NextResponse.json(
        { error: "Project not found" },
        { status: 404 },
      );
    }

    const project = await projectResponse.json();

    // Optional: Check if project already has an image
    if (!regenerate) {
      if (project.imageUrl && project.imageUrl !== "") {
        return NextResponse.json(
          {
            success: true,
            message:
              "Project already has an image. Use regenerate=true to force regeneration.",
            projectId: projectId,
            existingImageUrl: project.imageUrl,
            regenerated: false,
          },
          { status: 200 },
        );
      }
    }

    // Call n8n webhook to trigger AI image generation
    // New webhook expects: body.projectData with title, category, description
    // Webhook path: /webhook/image-gen (instead of /webhook/ai-image-generation)
    const n8nResponse = await fetch(
      `${n8nWebhookUrl}/webhook/image-gen`,
      {
        method: "POST",
        headers: {
          "Content-Type": "application/json",
          ...(n8nSecretToken && {
            Authorization: `Bearer ${n8nSecretToken}`,
          }),
        },
        body: JSON.stringify({
          projectId: projectId,
          projectData: {
            title: project.title || "Unknown Project",
            category: project.category || "Technology",
            description: project.description || "A clean minimalist visualization",
          },
          regenerate: regenerate,
          triggeredBy: "api",
          timestamp: new Date().toISOString(),
        }),
      },
    );

    if (!n8nResponse.ok) {
      const errorText = await n8nResponse.text();
      console.error("n8n webhook error:", errorText);

      return NextResponse.json(
        {
          error: "Failed to trigger image generation",
          message: "n8n workflow failed to execute",
          details: errorText,
        },
        { status: 500 },
      );
    }

    // The new webhook should return JSON with the pollinations.ai image URL
    // The pollinations.ai URL format is: https://image.pollinations.ai/prompt/...
    // This URL is stable and can be used directly
    const contentType = n8nResponse.headers.get("content-type");
    
    let imageUrl: string;
    let generatedAt: string;
    let fileSize: string | undefined;

    if (contentType?.includes("application/json")) {
      const result = await n8nResponse.json();
      // Handle JSON response - webhook should return the pollinations.ai URL
      // The URL from pollinations.ai is the direct image URL
      imageUrl = result.imageUrl || result.url || result.generatedPrompt || "";
      
      // If the webhook returns the pollinations.ai URL directly, use it
      // Format: https://image.pollinations.ai/prompt/...
      if (!imageUrl && typeof result === 'string' && result.includes('pollinations.ai')) {
        imageUrl = result;
      }
      
      generatedAt = result.generatedAt || new Date().toISOString();
      fileSize = result.fileSize;
    } else if (contentType?.startsWith("image/")) {
      // If webhook returns image binary, we need the URL from the workflow
      // For pollinations.ai, the URL should be constructed from the prompt
      // But ideally the webhook should return JSON with the URL
      return NextResponse.json(
        {
          error: "Webhook returned image binary instead of URL",
          message: "Please modify the n8n workflow to return JSON with the imageUrl field containing the pollinations.ai URL",
        },
        { status: 500 },
      );
    } else {
      // Try to parse as text/URL
      const textResponse = await n8nResponse.text();
      if (textResponse.includes('pollinations.ai') || textResponse.startsWith('http')) {
        imageUrl = textResponse.trim();
        generatedAt = new Date().toISOString();
      } else {
        return NextResponse.json(
          {
            error: "Unexpected response format from webhook",
            message: "Webhook should return JSON with imageUrl field containing the pollinations.ai URL",
          },
          { status: 500 },
        );
      }
    }

    if (!imageUrl) {
      return NextResponse.json(
        {
          error: "No image URL returned from webhook",
          message: "The n8n workflow should return the pollinations.ai image URL in the response",
        },
        { status: 500 },
      );
    }

    // If we got an image URL, we should update the project with it
    if (imageUrl) {
      // Update project with the new image URL
      const updateResponse = await fetch(
        `${process.env.NEXT_PUBLIC_API_URL || "http://localhost:3000"}/api/projects/${projectId}`,
        {
          method: "PUT",
          headers: {
            "Content-Type": "application/json",
            "x-admin-request": "true",
          },
          body: JSON.stringify({
            imageUrl: imageUrl,
          }),
        },
      );

      if (!updateResponse.ok) {
        console.warn("Failed to update project with image URL");
      }
    }

    return NextResponse.json(
      {
        success: true,
        message: "AI image generation completed successfully",
        projectId: projectId,
        imageUrl: imageUrl,
        generatedAt: generatedAt,
        fileSize: fileSize,
        regenerated: regenerate,
      },
      { status: 200 },
    );
  } catch (error) {
    console.error("Error in generate-image API:", error);
    return NextResponse.json(
      {
        error: "Internal server error",
        message: error instanceof Error ? error.message : "Unknown error",
      },
      { status: 500 },
    );
  }
}

/**
 * GET /api/n8n/generate-image?projectId=123
 *
 * Check the status of image generation for a project
 */
export async function GET(req: NextRequest) {
  try {
    const searchParams = req.nextUrl.searchParams;
    const projectId = searchParams.get("projectId");

    if (!projectId) {
      return NextResponse.json(
        { error: "projectId query parameter is required" },
        { status: 400 },
      );
    }

    // Fetch project to check image status
    const projectResponse = await fetch(
      `${process.env.NEXT_PUBLIC_API_URL || "http://localhost:3000"}/api/projects/${projectId}`,
      {
        method: "GET",
        cache: "no-store",
      },
    );

    if (!projectResponse.ok) {
      return NextResponse.json({ error: "Project not found" }, { status: 404 });
    }

    const project = await projectResponse.json();

    return NextResponse.json({
      projectId: parseInt(projectId),
      title: project.title,
      hasImage: !!project.imageUrl,
      imageUrl: project.imageUrl || null,
      updatedAt: project.updatedAt,
    });
  } catch (error) {
    console.error("Error checking image status:", error);
    return NextResponse.json(
      {
        error: "Internal server error",
        message: error instanceof Error ? error.message : "Unknown error",
      },
      { status: 500 },
    );
  }
}