import React, { useState } from 'react';
import { Create } from "@refinedev/antd";
import { useCreate, useNotification } from "@refinedev/core";
import { 
  Form, 
  Input, 
  Button, 
  Card, 
  Steps, 
  Alert, 
  Typography, 
  Space,
  Divider,
  Tag,
  Spin
} from 'antd';
import { 
  GitlabOutlined, 
  FileTextOutlined, 
  CheckCircleOutlined,
  ArrowLeftOutlined 
} from '@ant-design/icons';
import { useNavigate } from 'react-router';
import { API_URL } from '../../config';

const { Title, Text, Paragraph } = Typography;
const { Step } = Steps;

interface ComposeImportForm {
  app_name?: string;
  source_url: string;
  branch: string;
  compose_path: string;
}

interface ParsedService {
  name: string;
  source: 'build' | 'image';
  build_context?: string;
  dockerfile?: string;
  image?: string;
  ports?: string[];
  environment?: Record<string, string>;
  volumes?: string[];
}

interface ComposeReviewResult {
  app_name: string;
  valid: boolean;
  error?: string;
  services: ParsedService[];
}

export const AppImportCompose = () => {
  const [currentStep, setCurrentStep] = useState(0);
  const [form] = Form.useForm();
  const [parseResult, setParseResult] = useState<ComposeReviewResult | null>(null);
  const [loading, setLoading] = useState(false);
  const navigate = useNavigate();
  const { open } = useNotification();
  const { mutate: createApp } = useCreate();

  const handleParseCompose = async (values: ComposeImportForm) => {
    setLoading(true);
    try {
      // Call the backend API to parse the docker-compose.yml
      const response = await fetch(`${API_URL}/apps/import/review`, {
        method: 'POST',
        headers: {
          'Content-Type': 'application/json',
          'Authorization': `Bearer ${localStorage.getItem('byop-auth')}`,
        },
        body: JSON.stringify({
          source_url: values.source_url,
          branch: values.branch,
          compose_path: values.compose_path,
          app_name: values.app_name,
        }),
      });

      if (!response.ok) {
        throw new Error('Failed to parse docker-compose.yml');
      }

      const result: ComposeReviewResult = await response.json();
      
      if (!result.valid) {
        open?.({
          type: 'error',
          message: 'Invalid Compose File',
          description: result.error || 'The docker-compose.yml file could not be parsed.',
        });
        return;
      }
      
      setParseResult(result);
      setCurrentStep(1);
    } catch (error) {
      open?.({
        type: 'error',
        message: 'Parse Error',
        description: 'Failed to parse the docker-compose.yml file. Please check your repository URL and file path.',
      });
    } finally {
      setLoading(false);
    }
  };

  const handleCreateApp = async () => {
    if (!parseResult) return;

    setLoading(true);
    try {
      // Call the backend API to create the app and components
      const response = await fetch(`${API_URL}/apps/import/create`, {
        method: 'POST',
        headers: {
          'Content-Type': 'application/json',
          'Authorization': `Bearer ${localStorage.getItem('byop-auth')}`,
        },
        body: JSON.stringify({
          source_url: form.getFieldValue('source_url'),
          branch: form.getFieldValue('branch'),
          compose_path: form.getFieldValue('compose_path'),
          app_name: form.getFieldValue('app_name'),
          confirmed_app_name: parseResult.app_name,
        }),
      });

      if (!response.ok) {
        throw new Error('Failed to create app from compose');
      }

      const createdApp = await response.json();
      
      open?.({
        type: 'success',
        message: 'App Created Successfully',
        description: `Your app "${parseResult.app_name}" has been created with ${parseResult.services.length} components.`,
      });

      // Redirect to the new app's show page
      navigate(`/apps/show/${createdApp.id}`);
    } catch (error) {
      open?.({
        type: 'error',
        message: 'Creation Error',
        description: 'Failed to create the app. Please try again.',
      });
    } finally {
      setLoading(false);
    }
  };

  const renderImportForm = () => (
    <Card title="Import from docker-compose.yml" extra={
      <Button 
        type="text" 
        icon={<ArrowLeftOutlined />} 
        onClick={() => navigate('/apps/create')}
      >
        Back to Create Options
      </Button>
    }>
      <Alert
        message="Import your existing multi-service application"
        description="Provide your Git repository details and we'll parse your docker-compose.yml to automatically create components for each service."
        type="info"
        showIcon
        style={{ marginBottom: 24 }}
      />

      <Form 
        form={form}
        layout="vertical" 
        onFinish={handleParseCompose}
        initialValues={{
          branch: 'main',
          compose_path: 'docker-compose.yml'
        }}
      >
        <Form.Item
          label="App Name (Optional)"
          name="app_name"
          help="Leave empty to use the repository name"
        >
          <Input placeholder="e.g., my-awesome-app" />
        </Form.Item>

        <Form.Item
          label="Git Repository URL"
          name="source_url"
          rules={[
            { required: true, message: 'Please enter the Git repository URL' },
            { type: 'url', message: 'Please enter a valid URL' }
          ]}
        >
          <Input 
            prefix={<GitlabOutlined />}
            placeholder="https://github.com/username/repository.git" 
          />
        </Form.Item>

        <Form.Item
          label="Branch"
          name="branch"
          rules={[{ required: true, message: 'Please enter the branch name' }]}
        >
          <Input placeholder="main" />
        </Form.Item>

        <Form.Item
          label="Path to Compose File"
          name="compose_path"
          rules={[{ required: true, message: 'Please enter the path to docker-compose.yml' }]}
        >
          <Input 
            prefix={<FileTextOutlined />}
            placeholder="docker-compose.yml" 
          />
        </Form.Item>

        <Form.Item>
          <Button 
            type="primary" 
            htmlType="submit" 
            loading={loading}
            size="large"
          >
            Parse Compose File
          </Button>
        </Form.Item>
      </Form>
    </Card>
  );

  const renderReviewStep = () => (
    <Card title="Review Your Application">
      <Space direction="vertical" style={{ width: '100%' }} size="large">
        <Alert
          message={`We found ${parseResult?.services.length} services in your docker-compose.yml`}
          description="We will create a component for each service. Review the details below and click 'Create App and Components' to proceed."
          type="success"
          showIcon
        />

        <div>
          <Title level={4}>App Name: {parseResult?.app_name}</Title>
          <Divider />
          
          <Title level={5}>Services Found:</Title>
          <Space direction="vertical" style={{ width: '100%' }} size={16}>
            {parseResult?.services.map((service: ParsedService, index: number) => (
              <Card 
                key={index} 
                size="small" 
                title={
                  <Space>
                    <Tag color="blue">{service.name}</Tag>
                    <Text strong>Service: {service.name}</Text>
                  </Space>
                }
              >
                <Space direction="vertical" size="small">
                  {service.source === 'build' && service.build_context && (
                    <Text>
                      <strong>Source:</strong> Will be built from the <code>{service.build_context}</code> directory.
                      {service.dockerfile && <span> Using <code>{service.dockerfile}</code></span>}
                    </Text>
                  )}
                  {service.source === 'image' && service.image && (
                    <Text>
                      <strong>Source:</strong> Uses the public image <code>{service.image}</code>.
                    </Text>
                  )}
                  {service.ports && service.ports.length > 0 && (
                    <Text>
                      <strong>Ports:</strong> {service.ports.join(', ')}
                    </Text>
                  )}
                  {service.environment && Object.keys(service.environment).length > 0 && (
                    <Text>
                      <strong>Environment Variables:</strong> {Object.keys(service.environment).length} variables defined
                    </Text>
                  )}
                  {service.volumes && service.volumes.length > 0 && (
                    <Text>
                      <strong>Volumes:</strong> {service.volumes.length} volume mappings
                    </Text>
                  )}
                </Space>
              </Card>
            ))}
          </Space>
        </div>

        <Space>
          <Button 
            onClick={() => setCurrentStep(0)}
            disabled={loading}
          >
            Back to Edit
          </Button>
          <Button 
            type="primary" 
            size="large"
            loading={loading}
            onClick={handleCreateApp}
            icon={<CheckCircleOutlined />}
          >
            Create App and Components
          </Button>
        </Space>
      </Space>
    </Card>
  );

  return (
    <Create 
      title="Import from docker-compose.yml"
      breadcrumb={false}
      headerButtons={[]}
    >
      <Space direction="vertical" style={{ width: '100%' }} size="large">
        <Steps current={currentStep} size="small">
          <Step title="Import Details" description="Repository and compose file info" />
          <Step title="Review & Confirm" description="Verify services and create app" />
        </Steps>

        <Spin spinning={loading}>
          {currentStep === 0 && renderImportForm()}
          {currentStep === 1 && renderReviewStep()}
        </Spin>
      </Space>
    </Create>
  );
};