import { ToolConfig, ToolResponse } from '../types'

interface Message {
  role: 'system' | 'user' | 'assistant'
  content: string
}

export interface ChatParams {
  apiKey: string
  systemPrompt?: string
  context?: string
  model?: string
  temperature?: number
}

export interface ChatResponse extends ToolResponse {
  output: {
    content: string
    model: string
    tokens?: number
  }
}

export const reasonerTool: ToolConfig<ChatParams, ChatResponse> = {
  id: 'deepseek_reasoner',
  name: 'DeepSeek Reasoner',
  description:
    "Leverage DeepSeek's specialized reasoning model for complex problem-solving, logical analysis, and step-by-step deduction. Optimized for tasks requiring structured thinking and detailed explanations.",
  version: '1.0.0',

  params: {
    apiKey: {
      type: 'string',
      required: true,
      description: 'DeepSeek API key',
    },
    systemPrompt: {
      type: 'string',
      required: false,
      description: 'System prompt to guide the model',
    },
    context: {
      type: 'string',
      required: false,
      description: 'User input context',
    },
    model: {
      type: 'string',
      default: 'deepseek-reasoner',
      description: 'Model to use',
    },
    temperature: {
      type: 'number',
      required: false,
      description: 'Temperature (has no effect on reasoner)',
    },
  },

  request: {
    url: 'https://api.deepseek.com/v1/chat/completions',
    method: 'POST',
    headers: (params) => ({
      'Content-Type': 'application/json',
      Authorization: `Bearer ${params.apiKey}`,
    }),
    body: (params) => {
      const messages: Message[] = []

      if (params.systemPrompt) {
        messages.push({
          role: 'system',
          content: params.systemPrompt,
        })
      }

      // Always ensure the last message is a user message
      if (params.context) {
        messages.push({
          role: 'user',
          content: params.context,
        })
      } else if (params.systemPrompt) {
        // If we have a system prompt but no context, add an empty user message
        messages.push({
          role: 'user',
          content: 'Please respond.',
        })
      }

      return {
        model: 'deepseek-reasoner',
        messages,
      }
    },
  },

  async transformResponse(response: Response): Promise<ChatResponse> {
    if (!response.ok) {
      const error = await response.json()
      throw new Error(`DeepSeek API error: ${error.message || response.statusText}`)
    }

    const data = await response.json()
    return {
      success: true,
      output: {
        content: data.choices[0].message.content,
        model: data.model,
        tokens: data.usage?.total_tokens,
      },
    }
  },

  transformError(error: any): string {
    const message = error.error?.message || error.message
    const code = error.error?.type || error.code
    return `${message} (${code})`
  },
}