/**
 * Ollama Container
 *
 * Manages Ollama containers for running local LLMs.
 */

import type {
  IContainerConfig,
  ILoadedModel,
  TContainerType,
} from '../interfaces/container.ts';
import type {
  IChatCompletionRequest,
  IChatCompletionResponse,
  IChatCompletionChoice,
  IChatMessage,
} from '../interfaces/api.ts';
import { CONTAINER_IMAGES, CONTAINER_PORTS } from '../constants.ts';
import { logger } from '../logger.ts';
import { BaseContainer, type TModelPullProgress } from './base-container.ts';

/**
 * Ollama API response types
 */
interface IOllamaTagsResponse {
  models: Array<{
    name: string;
    size: number;
    digest: string;
    modified_at: string;
  }>;
}

interface IOllamaChatRequest {
  model: string;
  messages: Array<{
    role: string;
    content: string;
  }>;
  stream?: boolean;
  options?: {
    temperature?: number;
    top_p?: number;
    num_predict?: number;
    stop?: string[];
  };
}

interface IOllamaChatResponse {
  model: string;
  created_at: string;
  message: {
    role: string;
    content: string;
  };
  done: boolean;
  total_duration?: number;
  load_duration?: number;
  prompt_eval_count?: number;
  eval_count?: number;
}

interface IOllamaPullResponse {
  status: string;
  digest?: string;
  total?: number;
  completed?: number;
}

/**
 * Ollama container implementation
 */
export class OllamaContainer extends BaseContainer {
  public readonly type: TContainerType = 'ollama';
  public readonly displayName = 'Ollama';
  public readonly defaultImage = CONTAINER_IMAGES.OLLAMA;
  public readonly defaultPort = CONTAINER_PORTS.OLLAMA;

  constructor(config: IContainerConfig) {
    super(config);

    // Set defaults if not provided
    if (!config.image) {
      config.image = this.defaultImage;
    }
    if (!config.port) {
      config.port = this.defaultPort;
    }

    // Add default volume for model storage
    if (!config.volumes || config.volumes.length === 0) {
      config.volumes = [`modelgrid-ollama-${config.id}:/root/.ollama`];
    }
  }

  /**
   * Create Ollama container configuration
   */
  public static createConfig(
    id: string,
    name: string,
    gpuIds: string[],
    options: Partial<IContainerConfig> = {},
  ): IContainerConfig {
    return {
      id,
      name,
      type: 'ollama',
      image: options.image || CONTAINER_IMAGES.OLLAMA,
      gpuIds,
      port: options.port || CONTAINER_PORTS.OLLAMA,
      externalPort: options.externalPort,
      models: options.models || [],
      env: options.env,
      volumes: options.volumes || [`modelgrid-ollama-${id}:/root/.ollama`],
      autoStart: options.autoStart ?? true,
      restartPolicy: options.restartPolicy || 'unless-stopped',
      memoryLimit: options.memoryLimit,
      cpuLimit: options.cpuLimit,
      command: options.command,
    };
  }

  /**
   * Check if Ollama is healthy
   */
  public async isHealthy(): Promise<boolean> {
    try {
      const response = await this.fetch('/api/tags', { timeout: 5000 });
      return response.ok;
    } catch {
      return false;
    }
  }

  /**
   * List available models
   */
  public async listModels(): Promise<string[]> {
    try {
      const data = await this.fetchJson<IOllamaTagsResponse>('/api/tags');
      return (data.models || []).map((m) => m.name);
    } catch (error) {
      logger.warn(`Failed to list Ollama models: ${error instanceof Error ? error.message : String(error)}`);
      return [];
    }
  }

  /**
   * Get loaded models with details
   */
  public async getLoadedModels(): Promise<ILoadedModel[]> {
    try {
      const data = await this.fetchJson<IOllamaTagsResponse>('/api/tags');
      return (data.models || []).map((m) => ({
        name: m.name,
        size: m.size,
        format: m.digest.substring(0, 12),
        loaded: true, // Ollama doesn't distinguish loaded vs available
        requestCount: 0,
      }));
    } catch {
      return [];
    }
  }

  /**
   * Pull a model
   */
  public async pullModel(modelName: string, onProgress?: TModelPullProgress): Promise<boolean> {
    try {
      logger.info(`Pulling model: ${modelName}`);

      const response = await this.fetch('/api/pull', {
        method: 'POST',
        body: { name: modelName },
        timeout: 3600000, // 1 hour for large models
      });

      if (!response.ok) {
        throw new Error(`HTTP ${response.status}`);
      }

      // Read streaming response
      const reader = response.body?.getReader();
      if (!reader) {
        throw new Error('No response body');
      }

      const decoder = new TextDecoder();
      let lastStatus = '';

      while (true) {
        const { done, value } = await reader.read();
        if (done) break;

        const text = decoder.decode(value);
        const lines = text.split('\n').filter((l) => l.trim());

        for (const line of lines) {
          try {
            const data = JSON.parse(line) as IOllamaPullResponse;
            const status = data.status;

            if (status !== lastStatus) {
              lastStatus = status;
              let percent: number | undefined;

              if (data.total && data.completed) {
                percent = Math.round((data.completed / data.total) * 100);
              }

              if (onProgress) {
                onProgress({ model: modelName, status, percent });
              } else {
                const progressStr = percent !== undefined ? ` (${percent}%)` : '';
                logger.dim(`  ${status}${progressStr}`);
              }
            }
          } catch {
            // Invalid JSON line, skip
          }
        }
      }

      logger.success(`Model ${modelName} pulled successfully`);
      return true;
    } catch (error) {
      logger.error(`Failed to pull model ${modelName}: ${error instanceof Error ? error.message : String(error)}`);
      return false;
    }
  }

  /**
   * Remove a model
   */
  public async removeModel(modelName: string): Promise<boolean> {
    try {
      const response = await this.fetch('/api/delete', {
        method: 'DELETE',
        body: { name: modelName },
      });

      if (response.ok) {
        logger.success(`Model ${modelName} removed`);
        return true;
      }

      throw new Error(`HTTP ${response.status}`);
    } catch (error) {
      logger.error(`Failed to remove model ${modelName}: ${error instanceof Error ? error.message : String(error)}`);
      return false;
    }
  }

  /**
   * Send a chat completion request
   */
  public async chatCompletion(request: IChatCompletionRequest): Promise<IChatCompletionResponse> {
    const ollamaRequest: IOllamaChatRequest = {
      model: request.model,
      messages: request.messages.map((m) => ({
        role: m.role,
        content: m.content,
      })),
      stream: false,
      options: {
        temperature: request.temperature,
        top_p: request.top_p,
        num_predict: request.max_tokens,
        stop: Array.isArray(request.stop) ? request.stop : request.stop ? [request.stop] : undefined,
      },
    };

    const response = await this.fetchJson<IOllamaChatResponse>('/api/chat', {
      method: 'POST',
      body: ollamaRequest,
      timeout: 300000, // 5 minutes
    });

    // Convert to OpenAI format
    const created = Math.floor(Date.now() / 1000);

    const choice: IChatCompletionChoice = {
      index: 0,
      message: {
        role: 'assistant',
        content: response.message.content,
      },
      finish_reason: response.done ? 'stop' : null,
    };

    return {
      id: this.generateRequestId(),
      object: 'chat.completion',
      created,
      model: request.model,
      choices: [choice],
      usage: {
        prompt_tokens: response.prompt_eval_count || 0,
        completion_tokens: response.eval_count || 0,
        total_tokens: (response.prompt_eval_count || 0) + (response.eval_count || 0),
      },
    };
  }

  /**
   * Stream a chat completion request
   */
  public async chatCompletionStream(
    request: IChatCompletionRequest,
    onChunk: (chunk: string) => void,
  ): Promise<void> {
    const ollamaRequest: IOllamaChatRequest = {
      model: request.model,
      messages: request.messages.map((m) => ({
        role: m.role,
        content: m.content,
      })),
      stream: true,
      options: {
        temperature: request.temperature,
        top_p: request.top_p,
        num_predict: request.max_tokens,
        stop: Array.isArray(request.stop) ? request.stop : request.stop ? [request.stop] : undefined,
      },
    };

    const response = await this.fetch('/api/chat', {
      method: 'POST',
      body: ollamaRequest,
      timeout: 300000,
    });

    if (!response.ok) {
      throw new Error(`HTTP ${response.status}`);
    }

    const reader = response.body?.getReader();
    if (!reader) {
      throw new Error('No response body');
    }

    const decoder = new TextDecoder();
    const requestId = this.generateRequestId();
    const created = Math.floor(Date.now() / 1000);

    while (true) {
      const { done, value } = await reader.read();
      if (done) break;

      const text = decoder.decode(value);
      const lines = text.split('\n').filter((l) => l.trim());

      for (const line of lines) {
        try {
          const data = JSON.parse(line) as IOllamaChatResponse;

          // Convert to OpenAI streaming format
          const chunk = {
            id: requestId,
            object: 'chat.completion.chunk',
            created,
            model: request.model,
            choices: [
              {
                index: 0,
                delta: {
                  content: data.message.content,
                } as Partial<IChatMessage>,
                finish_reason: data.done ? 'stop' : null,
              },
            ],
          };

          onChunk(`data: ${JSON.stringify(chunk)}\n\n`);

          if (data.done) {
            onChunk('data: [DONE]\n\n');
          }
        } catch {
          // Invalid JSON, skip
        }
      }
    }
  }
}