import { ServiceError } from '../types';
import { net } from 'electron';

interface OllamaModel {
  name: string;
  modified_at: string;
  size: number;
  digest: string;
}

interface OllamaModelStatus {
  installed: boolean;
  installing: boolean;
}

interface OllamaListResponse {
  models: Array<{
    name: string;
    model: string;
    modified_at: string;
    size: number;
    digest: string;
  }>;
}

interface OllamaChatResponse {
  message: {
    content: string;
  };
}

interface OllamaChatParams {
  model: string;
  messages: Array<{ role: string; content: string }>;
  temperature?: number;
  onChunk?: (chunk: string) => void;
}

class OllamaService {
  private baseUrl: string = 'http://127.0.0.1:11434';
  private _lastProgress: number | null = null;

  private async makeRequest<T>(
    path: string,
    method: string = 'GET',
    body?: any,
    onChunk?: (chunk: string) => void
  ): Promise<T> {
    return new Promise((resolve, reject) => {
      try {
        const url = new URL(path, this.baseUrl);
        const request = net.request({
          url: url.toString(),
          method,
          headers: {
            'Content-Type': 'application/json',
          }
        });

        let responseData = '';
        let streamBuffer = '';

        request.on('response', (response) => {
          if (response.statusCode !== 200) {
            const error = new Error(`HTTP error! status: ${response.statusCode}`);
            console.error('Ollama request failed:', {
              path,
              statusCode: response.statusCode,
              error
            });
            reject(error);
            return;
          }

          response.on('data', (chunk) => {
            try {
              const chunkStr = chunk.toString();
              
              if (path === '/api/chat' || path === '/api/pull') {
                // Handle streaming responses
                streamBuffer += chunkStr;
                const lines = streamBuffer.split('\n');
                
                // Process all complete lines except the last one
                for (let i = 0; i < lines.length - 1; i++) {
                  const line = lines[i].trim();
                  if (!line) continue;
                  
                  try {
                    const parsed = JSON.parse(line);
                    if (path === '/api/chat' && parsed.message?.content && onChunk) {
                      onChunk(parsed.message.content);
                    } else if (path === '/api/pull' && onChunk) {
                      if (parsed.status === 'success') {
                        onChunk('downloading: 100% complete');
                      } else if (parsed.total && parsed.completed !== undefined) {
                        const percentage = ((parsed.completed / parsed.total) * 100).toFixed(1);
                        onChunk(`downloading: ${percentage}% complete`);
                      } else if (parsed.status) {
                        onChunk(parsed.status);
                      }
                    }
                  } catch (e) {
                    console.warn('Failed to parse chunk:', { line, error: e });
                  }
                }
                
                // Keep the last potentially incomplete line
                streamBuffer = lines[lines.length - 1];
              } else {
                // For non-streaming endpoints, accumulate the entire response
                responseData += chunkStr;
              }
            } catch (e) {
              console.error('Error processing chunk:', e);
            }
          });

          response.on('end', () => {
            try {
              if (path === '/api/chat' || path === '/api/pull') {
                // Handle any remaining data in the streaming buffer
                if (streamBuffer.trim()) {
                  try {
                    const parsed = JSON.parse(streamBuffer);
                    if (path === '/api/chat' && parsed.message?.content && onChunk) {
                      onChunk(parsed.message.content);
                    } else if (path === '/api/pull' && onChunk) {
                      if (parsed.status === 'success') {
                        onChunk('downloading: 100% complete');
                      } else if (parsed.total && parsed.completed !== undefined) {
                        const percentage = ((parsed.completed / parsed.total) * 100).toFixed(1);
                        onChunk(`downloading: ${percentage}% complete`);
                      } else if (parsed.status) {
                        onChunk(parsed.status);
                      }
                    }
                  } catch (e) {
                    console.warn('Failed to parse final chunk:', { buffer: streamBuffer, error: e });
                  }
                }
                // Resolve streaming endpoints with success response
                resolve({ success: true } as T);
              } else {
                // For non-streaming endpoints, parse the accumulated response
                const trimmedResponse = responseData.trim();
                if (!trimmedResponse) {
                  throw new Error('Empty response received');
                }
                resolve(JSON.parse(trimmedResponse) as T);
              }
            } catch (e) {
              reject(new Error(`Failed to process response: ${e.message}`));
            }
          });
        });

        request.on('error', (error) => {
          console.error('Request error:', {
            path,
            error: error.message
          });
          reject(error);
        });

        if (body) {
          const bodyStr = JSON.stringify(body);
          console.log('Sending request:', {
            path,
            method,
            body: bodyStr
          });
          request.write(bodyStr);
        }
        
        request.end();
      } catch (e) {
        console.error('Failed to make request:', e);
        reject(e);
      }
    });
  }

  async getModels(): Promise<string[]> {
    try {
      const response = await this.makeRequest<OllamaListResponse>('/api/tags');
      return response.models.map(model => model.name);
    } catch (error) {
      console.error('Error fetching Ollama models:', error);
      throw new ServiceError(
        error instanceof Error ? error.message : 'Failed to fetch Ollama models'
      );
    }
  }

  async chat(params: OllamaChatParams): Promise<OllamaChatResponse> {
    if (!params?.model || !params?.messages?.length) {
      throw new ServiceError('Invalid chat parameters: model and messages are required');
    }

    try {
      console.log('Starting chat request:', {
        model: params.model,
        messageCount: params.messages.length
      });

      const { onChunk, temperature, ...requestParams } = params;
      const response = await this.makeRequest<OllamaChatResponse>(
        '/api/chat',
        'POST',
        {
          ...requestParams,
          stream: true,
          temperature: temperature ?? 0.7
        },
        onChunk
      );

      if (!response?.message) {
        throw new Error('Invalid response format from Ollama');
      }

      return response;
    } catch (error) {
      const errorMessage = error instanceof Error ? error.message : 'Failed to chat with Ollama';
      console.error('Chat error:', {
        error: errorMessage,
        params: {
          model: params.model,
          messageCount: params.messages.length
        }
      });
      throw new ServiceError(errorMessage);
    }
  }

  updateBaseUrl(baseUrl: string) {
    this.baseUrl = baseUrl;
  }

  async checkModel(modelName: string): Promise<OllamaModelStatus> {
    try {
      const models = await this.getModels();
      return {
        installed: models.includes(modelName),
        installing: false
      };
    } catch (error) {
      console.error('Error checking model:', error);
      throw new ServiceError(
        error instanceof Error ? error.message : 'Failed to check model status'
      );
    }
  }

  async pullModel(modelName: string, onProgress?: (status: string) => void): Promise<void> {
    try {
      console.log('Starting model pull for:', modelName);
      
      // Make a direct request using net.request to handle streaming properly
      await new Promise<void>((resolve, reject) => {
        const request = net.request({
          url: `${this.baseUrl}/api/pull`,
          method: 'POST',
          headers: {
            'Content-Type': 'application/json',
          }
        });

        request.on('response', (response) => {
          if (response.statusCode !== 200) {
            reject(new Error(`HTTP error! status: ${response.statusCode}`));
            return;
          }

          let buffer = '';
          response.on('data', (chunk) => {
            buffer += chunk.toString();
            const lines = buffer.split('\n');
            buffer = lines.pop() || ''; // Keep the last incomplete line

            for (const line of lines) {
              if (!line.trim()) continue;
              
              try {
                const data = JSON.parse(line);
                console.log('Pull progress data:', data);
                
                if (data.status === 'success') {
                  if (onProgress) onProgress('downloading: 100% complete');
                } else if (data.total && typeof data.completed === 'number') {
                  // Round to nearest whole number to reduce update frequency
                  const percentage = Math.round((data.completed / data.total) * 100);
                  // Cache the last reported progress to avoid duplicate updates
                  if (onProgress && (!this._lastProgress || percentage !== this._lastProgress)) {
                    this._lastProgress = percentage;
                    onProgress(`downloading: ${percentage}% complete`);
                  }
                } else if (data.status) {
                  if (onProgress) onProgress(data.status);
                }
              } catch (e) {
                console.warn('Failed to parse progress data:', e);
              }
            }
          });

          response.on('end', () => {
            // Process any remaining data in buffer
            if (buffer.trim()) {
              try {
                const data = JSON.parse(buffer);
                if (data.status === 'success') {
                  if (onProgress) onProgress('downloading: 100% complete');
                }
              } catch (e) {
                console.warn('Failed to parse final data:', e);
              }
            }
            resolve();
          });

          response.on('error', (error) => {
            console.error('Response error:', error);
            reject(error);
          });
        });

        request.on('error', (error) => {
          console.error('Request error:', error);
          reject(error);
        });

        // Send the request with the model name
        const body = JSON.stringify({ name: modelName });
        console.log('Sending pull request with body:', body);
        request.write(body);
        request.end();
      });

      // After successful pull, verify the model exists
      console.log('Pull completed, verifying model installation...');
      
      // Give Ollama some time to process
      await new Promise(resolve => setTimeout(resolve, 2000));
      
      const models = await this.getModels();
      console.log('Available models:', models);
      
      if (!models.includes(modelName)) {
        throw new ServiceError('Model pull completed but model is not available in Ollama');
      }
    } catch (error) {
      console.error('Error pulling model:', error);
      throw new ServiceError(
        error instanceof Error ? error.message : 'Failed to pull model'
      );
    }
  }
}

export const ollamaService = new OllamaService();