'use client';

import { useState } from 'react';
import { Button } from '@headlessui/react';
import { SelectInput, TextInput, Checkbox } from '@/components/formInputs';
import Card from '@/components/Card';
import { apiClient } from '@/utils/api';
import { JobConfig } from '@/types';
import useSettings from '@/hooks/useSettings';
import { upsertJob } from '@/utils/storage/jobStorage';
import { useAuth } from '@/contexts/AuthContext';

interface HFJobsWorkflowProps {
  jobConfig: JobConfig;
  onComplete: (jobId: string, localJobId?: string) => void;
}

type Step = 'validate' | 'upload' | 'submit' | 'complete';

export default function HFJobsWorkflow({ jobConfig, onComplete }: HFJobsWorkflowProps) {
  const { settings } = useSettings();
  const { token: authToken } = useAuth();
  const [defaultNamespace, setDefaultNamespace] = useState('');
  const [currentStep, setCurrentStep] = useState<Step>('validate');
  const [loading, setLoading] = useState(false);
  const [error, setError] = useState<string | null>(null);
  
  // Form state
  const [datasetSource, setDatasetSource] = useState<'upload' | 'existing'>('upload');
  const [datasetName, setDatasetName] = useState(`${jobConfig.config.name}-dataset`);
  const [existingDatasetId, setExistingDatasetId] = useState('');
  const [hardware, setHardware] = useState(settings.HF_JOBS_DEFAULT_HARDWARE || 'a100-large');
  const [namespace, setNamespace] = useState(settings.HF_JOBS_NAMESPACE || '');
  const [autoUpload, setAutoUpload] = useState(true);
  
  // Progress state
  const [validationResult, setValidationResult] = useState<any>(null);
  const [uploadResult, setUploadResult] = useState<any>(null);
  const [jobResult, setJobResult] = useState<any>(null);

  const validateToken = async () => {
    setLoading(true);
    setError(null);
    
    const effectiveToken = authToken || settings.HF_TOKEN;

    try {
      if (!effectiveToken) {
        throw new Error('A valid Hugging Face token is required to continue.');
      }

      const response = await apiClient.post('/api/hf-hub', {
        action: 'whoami',
        token: effectiveToken,
      });

      if (response.data.user) {
        setValidationResult(response.data.user);
        const resolvedName = response.data.user.name || '';
        setDefaultNamespace(resolvedName);
        if (!namespace) {
          setNamespace(resolvedName);
        }
        setCurrentStep('upload');
      }
    } catch (err: any) {
      setError(err.response?.data?.error || 'Failed to validate token');
    } finally {
      setLoading(false);
    }
  };

  const uploadDataset = async () => {
    setLoading(true);
    setError(null);

    const effectiveToken = authToken || settings.HF_TOKEN;

    try {
      if (!effectiveToken) {
        throw new Error('A valid Hugging Face token is required to continue.');
      }

      const resolvedNamespace = namespace || defaultNamespace;
      if (!resolvedNamespace) {
        throw new Error('Unable to determine a namespace. Validate your HF token or set a namespace in Settings.');
      }

      if (datasetSource === 'existing') {
        // Use existing dataset - just validate it exists
        if (!existingDatasetId) {
          throw new Error('Please enter a dataset ID');
        }
        
        // Validate dataset exists
        const validateResponse = await apiClient.post('/api/hf-hub', {
          action: 'validateDataset',
          token: effectiveToken,
          datasetId: existingDatasetId,
        });

        if (validateResponse.data.exists) {
          setUploadResult({
            repoId: existingDatasetId,
            url: `https://huggingface.co/datasets/${existingDatasetId}`,
            existing: true,
          });
          setCurrentStep('submit');
        } else {
          throw new Error(`Dataset ${existingDatasetId} not found or not accessible`);
        }
      } else {
        if (!resolvedNamespace) {
          throw new Error('Unable to determine a namespace. Validate your HF token or set a namespace in Settings.');
        }
        // Upload new dataset
        // First, create the dataset repository
        const createResponse = await apiClient.post('/api/hf-hub', {
          action: 'createDataset',
          token: effectiveToken,
          namespace: resolvedNamespace,
          datasetName,
        });

        if (!createResponse.data.success) {
          throw new Error('Failed to create dataset repository');
        }

        // Get dataset path from first dataset in config
        const datasetPath = jobConfig.config.process[0].datasets[0]?.folder_path;
        if (!datasetPath || datasetPath.trim() === '' || datasetPath === datasetName) {
          throw new Error('Dataset path could not be resolved. Please ensure the dataset folder exists on the host.');
        }

        // Upload dataset files
        const uploadResponse = await apiClient.post('/api/hf-hub', {
          action: 'uploadDataset',
          token: effectiveToken,
          namespace: resolvedNamespace,
          datasetName,
          datasetPath,
        });

        if (uploadResponse.data.success) {
          setUploadResult({
            repoId: uploadResponse.data.repoId,
            url: `https://huggingface.co/datasets/${uploadResponse.data.repoId}`,
            existing: false,
          });
          setCurrentStep('submit');
        }
      }
    } catch (err: any) {
      setError(err.response?.data?.error || 'Failed to process dataset');
    } finally {
      setLoading(false);
    }
  };

  const submitJob = async () => {
    setLoading(true);
    setError(null);

    const effectiveToken = authToken || settings.HF_TOKEN;

    try {
      const resolvedNamespace = namespace || defaultNamespace;
      if (!resolvedNamespace) {
        throw new Error('Unable to determine a namespace. Validate your HF token or set a namespace in Settings.');
      }
      if (!effectiveToken) {
        throw new Error('A valid Hugging Face token is required to continue.');
      }
      const datasetRepo =
        uploadResult?.repoId ||
        (datasetSource === 'existing'
          ? existingDatasetId
          : `${resolvedNamespace}/${datasetName}`);
      
      const response = await apiClient.post('/api/hf-jobs', {
        action: 'submitJob',
        token: effectiveToken,
        hardware,
        namespace: resolvedNamespace,
        jobConfig,
        datasetRepo,
      });

      if (response.data.success) {
        const hfJobId = response.data.jobId;
        
        // Save job to local database for tracking
        let localJobId = undefined;
        try {
          const savedJob = await upsertJob({
            name: `${jobConfig.config.name}-hf-cloud`,
            gpu_ids: hardware,
            job_config: {
              ...jobConfig,
              hf_job_id: hfJobId,
              hf_job_url:
                hfJobId !== 'unknown' && resolvedNamespace
                  ? `https://huggingface.co/jobs/${resolvedNamespace}/${hfJobId}`
                  : null,
              dataset_repo: datasetRepo,
              hardware,
              is_hf_job: true,
              training_backend: 'hf-jobs',
              hf_job_submitted: true,
            },
            info: response.data.message || 'HF Job submitted',
            status: 'submitted',
          });

          localJobId = savedJob.id;
          console.log('Saved HF Job to local storage:', savedJob);
        } catch (localSaveError: any) {
          console.warn('Failed to save HF Job locally:', localSaveError);
          // Don't fail the whole process if local save fails
        }
        
        setJobResult({
          jobId: hfJobId,
          message: response.data.message,
          localJobId: localJobId,
        });
        setCurrentStep('complete');
        onComplete(hfJobId, localJobId);
      }
    } catch (err: any) {
      setError(err.response?.data?.error || 'Failed to submit job');
    } finally {
      setLoading(false);
    }
  };

  const renderStepContent = () => {
    switch (currentStep) {
      case 'validate':
        return (
          <Card title="Validate HF Token">
            <div className="space-y-4">
              <p className="text-sm text-gray-400">
                First, let's validate your Hugging Face token and get your username for dataset uploads.
              </p>
              
              {validationResult && (
                <div className="p-3 bg-green-900/20 border border-green-700 rounded">
                  <p className="text-green-400">
                    ✓ Token valid! Logged in as: <strong>{validationResult.name}</strong>
                  </p>
                </div>
              )}

              <Button
                onClick={validateToken}
                disabled={loading || !(authToken || settings.HF_TOKEN)}
                className="w-full px-4 py-2 bg-blue-600 hover:bg-blue-700 text-white rounded disabled:opacity-50"
              >
                {loading ? 'Validating...' : 'Validate Token'}
              </Button>
            </div>
          </Card>
        );

      case 'upload':
        return (
          <Card title="Dataset Configuration">
            <div className="space-y-4">
              <p className="text-sm text-gray-400">
                Choose whether to upload a new dataset or use an existing one from HF Hub.
              </p>

              <SelectInput
                label="Dataset Source"
                value={datasetSource}
                onChange={(value) => setDatasetSource(value as 'upload' | 'existing')}
                options={[
                  { value: 'upload', label: 'Upload New Dataset' },
                  { value: 'existing', label: 'Use Existing HF Dataset' }
                ]}
              />

              {datasetSource === 'upload' ? (
                <>
                  <TextInput
                    label="Dataset Name"
                    value={datasetName}
                    onChange={setDatasetName}
                    placeholder="my-training-dataset"
                    required
                  />

                  <TextInput
                    label="Namespace"
                    value={namespace}
                    onChange={setNamespace}
                    placeholder="your-username or org-name"
                    required
                  />
                </>
              ) : (
                <>
                  <TextInput
                    label="Existing Dataset ID"
                    value={existingDatasetId}
                    onChange={setExistingDatasetId}
                    placeholder="e.g. multimodalart/flux-tarot-v1 or username/dataset-name"
                    required
                  />
                  <p className="text-xs text-gray-500">
                    Enter the full dataset ID (namespace/name) from HuggingFace Hub
                  </p>
                </>
              )}

              {uploadResult && (
                <div className="p-3 bg-green-900/20 border border-green-700 rounded">
                  <p className="text-green-400">
                    ✓ Dataset {uploadResult.existing ? 'validated' : 'uploaded'} successfully!
                  </p>
                  <p className="text-sm text-gray-400 mt-1">
                    {uploadResult.existing ? 'Using dataset:' : 'View at:'} <a href={uploadResult.url} target="_blank" rel="noopener noreferrer" className="text-blue-400 underline">{uploadResult.repoId}</a>
                  </p>
                </div>
              )}

              <Button
                onClick={uploadDataset}
                disabled={loading || (datasetSource === 'upload' ? (!datasetName || !namespace) : !existingDatasetId)}
                className="w-full px-4 py-2 bg-blue-600 hover:bg-blue-700 text-white rounded disabled:opacity-50"
              >
                {loading ? (datasetSource === 'upload' ? 'Uploading...' : 'Validating...') : (datasetSource === 'upload' ? 'Upload Dataset' : 'Validate Dataset')}
              </Button>
            </div>
          </Card>
        );

      case 'submit':
        return (
          <Card title="Submit Training Job">
            <div className="space-y-4">
              <p className="text-sm text-gray-400">
                Configure and submit your training job to HF Jobs.
              </p>

              <SelectInput
                label="Hardware"
                value={hardware}
                onChange={setHardware}
                options={[
                  { value: 'cpu-basic', label: 'CPU Basic' },
                  { value: 'cpu-upgrade', label: 'CPU Upgrade' },
                  { value: 't4-small', label: 'T4 Small' },
                  { value: 't4-medium', label: 'T4 Medium' },
                  { value: 'l4x1', label: 'L4x1' },
                  { value: 'l4x4', label: 'L4x4' },
                  { value: 'a10g-small', label: 'A10G Small' },
                  { value: 'a10g-large', label: 'A10G Large' },
                  { value: 'a10g-largex2', label: 'A10G Large x2' },
                  { value: 'a10g-largex4', label: 'A10G Large x4' },
                  { value: 'a100-large', label: 'A100 Large' },
                  { value: 'v5e-1x1', label: 'TPU v5e-1x1' },
                  { value: 'v5e-2x2', label: 'TPU v5e-2x2' },
                  { value: 'v5e-2x4', label: 'TPU v5e-2x4' },
                ]}
              />

              <Checkbox
                label="Auto-upload trained model to HF Hub"
                checked={autoUpload}
                onChange={setAutoUpload}
              />

              {jobResult && (
                <div className="p-3 bg-green-900/20 border border-green-700 rounded">
                  <p className="text-green-400">
                    ✓ Job submitted successfully!
                  </p>
                  <p className="text-sm text-gray-400 mt-1">
                    Job ID: <code className="bg-gray-800 px-2 py-1 rounded text-xs">{jobResult.jobId}</code>
                  </p>
                </div>
              )}

              <Button
                onClick={submitJob}
                disabled={loading || !hardware}
                className="w-full px-4 py-2 bg-green-600 hover:bg-green-700 text-white rounded disabled:opacity-50"
              >
                {loading ? 'Submitting...' : 'Submit Training Job'}
              </Button>
            </div>
          </Card>
        );

      case 'complete':
        return (
          <Card title="Job Submitted Successfully">
            <div className="space-y-4">
              <div className="p-4 bg-green-900/20 border border-green-700 rounded">
                <h3 className="text-lg font-semibold text-green-400 mb-2">🎉 Training job submitted!</h3>
                <p className="text-sm text-gray-300 mb-2">
                  Your training job has been submitted to Hugging Face Jobs and is now running in the cloud.
                </p>
                <div className="space-y-2">
                  <p className="text-sm">
                    <strong>Job ID:</strong> <code className="bg-gray-800 px-2 py-1 rounded text-xs">{jobResult?.jobId}</code>
                  </p>
                  {jobResult?.jobId && jobResult.jobId !== 'unknown' && (
                    <p className="text-sm">
                      <strong>Monitor Job:</strong> <a 
                        href={`https://huggingface.co/jobs/${namespace}/${jobResult.jobId}`} 
                        target="_blank" 
                        rel="noopener noreferrer" 
                        className="text-blue-400 underline"
                      >
                        View on HF Jobs →
                      </a>
                    </p>
                  )}
                  <p className="text-sm">
                    <strong>Dataset:</strong> <a href={uploadResult?.url} target="_blank" rel="noopener noreferrer" className="text-blue-400 underline">{uploadResult?.repoId}</a>
                  </p>
                  <p className="text-sm">
                    <strong>Hardware:</strong> {hardware}
                  </p>
                </div>
              </div>

              <div className="text-sm text-gray-400 space-y-2">
                <p><strong>Next steps:</strong></p>
                <ul className="list-disc list-inside space-y-1 ml-4">
                  <li>Monitor your job progress using: <code className="bg-gray-800 px-2 py-1 rounded text-xs">hf jobs logs {jobResult?.jobId}</code></li>
                  <li>The trained model will be uploaded to: <code className="bg-gray-800 px-2 py-1 rounded text-xs">{namespace}/{jobConfig.config.name}-lora</code></li>
                  <li>You'll receive notifications when training completes</li>
                </ul>
              </div>
            </div>
          </Card>
        );

      default:
        return null;
    }
  };

  return (
    <div className="space-y-6">
      {/* Progress indicator */}
      <div className="flex items-center justify-between mb-6">
        {(['validate', 'upload', 'submit', 'complete'] as Step[]).map((step, index) => (
          <div key={step} className="flex items-center">
            <div className={`w-8 h-8 rounded-full flex items-center justify-center text-sm font-semibold ${
              currentStep === step 
                ? 'bg-blue-600 text-white' 
                : index < (['validate', 'upload', 'submit', 'complete'] as Step[]).indexOf(currentStep)
                ? 'bg-green-600 text-white'
                : 'bg-gray-600 text-gray-300'
            }`}>
              {index + 1}
            </div>
            {index < 3 && (
              <div className={`w-16 h-1 mx-2 ${
                index < (['validate', 'upload', 'submit', 'complete'] as Step[]).indexOf(currentStep)
                  ? 'bg-green-600'
                  : 'bg-gray-600'
              }`} />
            )}
          </div>
        ))}
      </div>

      {/* Error display */}
      {error && (
        <div className="p-4 bg-red-900/20 border border-red-700 rounded">
          <p className="text-red-400">{error}</p>
        </div>
      )}

      {/* Current step content */}
      {renderStepContent()}
    </div>
  );
}