ccs/src/copilot/copilot-models.ts

/**
 * Copilot Model Catalog
 *
 * Manages available models from copilot-api.
 * Based on GitHub Copilot supported models:
 * https://docs.github.com/copilot/reference/ai-models/supported-models
 */

import * as http from 'http';
import { CopilotModel } from './types';

/**
 * Default models available through copilot-api.
 * Used as fallback when API is not reachable.
 * Source: GitHub Copilot Supported Models (Dec 2025)
 *
 * Plan tiers: free, pro, pro+, business, enterprise
 * Multipliers: 0 = free tier, 0.25-0.33 = cheap, 1 = standard, 3-10 = premium
 */
export const DEFAULT_COPILOT_MODELS: CopilotModel[] = [
  // Anthropic Models - All require paid Copilot subscription
  {
    id: 'claude-sonnet-4.5',
    name: 'Claude Sonnet 4.5',
    provider: 'anthropic',
    minPlan: 'pro',
    multiplier: 1,
  },
  {
    id: 'claude-sonnet-4',
    name: 'Claude Sonnet 4',
    provider: 'anthropic',
    minPlan: 'pro',
    multiplier: 1,
  },
  {
    id: 'claude-opus-4.5',
    name: 'Claude Opus 4.5',
    provider: 'anthropic',
    minPlan: 'pro',
    multiplier: 3,
    preview: true,
  },
  {
    id: 'claude-opus-4.1',
    name: 'Claude Opus 4.1',
    provider: 'anthropic',
    minPlan: 'pro',
    multiplier: 10,
  },
  {
    id: 'claude-haiku-4.5',
    name: 'Claude Haiku 4.5',
    provider: 'anthropic',
    minPlan: 'pro', // Requires paid Copilot subscription
    multiplier: 0.33,
  },

  // OpenAI Models
  {
    id: 'gpt-5.2',
    name: 'GPT-5.2',
    provider: 'openai',
    minPlan: 'pro',
    multiplier: 1,
    preview: true,
  },
  {
    id: 'gpt-5.1-codex-max',
    name: 'GPT-5.1 Codex Max',
    provider: 'openai',
    minPlan: 'pro',
    multiplier: 1,
  },
  { id: 'gpt-5.1-codex', name: 'GPT-5.1 Codex', provider: 'openai', minPlan: 'pro', multiplier: 1 },
  {
    id: 'gpt-5.1-codex-mini',
    name: 'GPT-5.1 Codex Mini',
    provider: 'openai',
    minPlan: 'pro',
    multiplier: 0.33,
    preview: true,
  },
  { id: 'gpt-5.1', name: 'GPT-5.1', provider: 'openai', minPlan: 'pro', multiplier: 1 },
  {
    id: 'gpt-5-codex',
    name: 'GPT-5 Codex',
    provider: 'openai',
    minPlan: 'pro',
    multiplier: 1,
    preview: true,
  },
  { id: 'gpt-5', name: 'GPT-5', provider: 'openai', minPlan: 'pro', multiplier: 1 },
  { id: 'gpt-5-mini', name: 'GPT-5 Mini', provider: 'openai', minPlan: 'free', multiplier: 0 },
  {
    id: 'gpt-4.1',
    name: 'GPT-4.1',
    provider: 'openai',
    isDefault: true,
    minPlan: 'free',
    multiplier: 0,
  },

  // Google Models
  {
    id: 'gemini-3-pro',
    name: 'Gemini 3 Pro',
    provider: 'openai',
    minPlan: 'pro',
    multiplier: 1,
    preview: true,
  },
  {
    id: 'gemini-3-flash',
    name: 'Gemini 3 Flash',
    provider: 'openai',
    minPlan: 'pro',
    multiplier: 0.33,
    preview: true,
  },
  {
    id: 'gemini-2.5-pro',
    name: 'Gemini 2.5 Pro',
    provider: 'openai',
    minPlan: 'pro',
    multiplier: 1,
  },

  // xAI Models
  {
    id: 'grok-code-fast-1',
    name: 'Grok Code Fast 1',
    provider: 'openai',
    minPlan: 'pro',
    multiplier: 0.25,
  },

  // Fine-tuned Models
  {
    id: 'raptor-mini',
    name: 'Raptor Mini',
    provider: 'openai',
    minPlan: 'free',
    multiplier: 0,
    preview: true,
  },
];

/**
 * Fetch available models from running copilot-api daemon.
 *
 * @param port The port copilot-api is running on
 * @returns List of available models
 */
export async function fetchModelsFromDaemon(port: number): Promise<CopilotModel[]> {
  return new Promise((resolve) => {
    const req = http.request(
      {
        // Use 127.0.0.1 instead of localhost for more reliable local connections
        hostname: '127.0.0.1',
        port,
        path: '/v1/models',
        method: 'GET',
        timeout: 5000,
      },
      (res) => {
        let data = '';

        res.on('data', (chunk) => {
          data += chunk;
        });

        res.on('end', () => {
          try {
            const response = JSON.parse(data) as { data?: Array<{ id: string }> };
            if (response.data && Array.isArray(response.data)) {
              const models: CopilotModel[] = response.data.map((m) => ({
                id: m.id,
                name: formatModelName(m.id),
                provider: detectProvider(m.id),
                isDefault: m.id === 'gpt-4.1', // Free tier default
              }));
              resolve(models.length > 0 ? models : DEFAULT_COPILOT_MODELS);
            } else {
              resolve(DEFAULT_COPILOT_MODELS);
            }
          } catch {
            resolve(DEFAULT_COPILOT_MODELS);
          }
        });
      }
    );

    req.on('error', () => {
      resolve(DEFAULT_COPILOT_MODELS);
    });

    req.on('timeout', () => {
      req.destroy();
      resolve(DEFAULT_COPILOT_MODELS);
    });

    req.end();
  });
}

/**
 * Get available models (from daemon or defaults).
 */
export async function getAvailableModels(port: number): Promise<CopilotModel[]> {
  return fetchModelsFromDaemon(port);
}

/**
 * Get the default model.
 * Uses gpt-4.1 as it's available on free tier.
 */
export function getDefaultModel(): string {
  return 'gpt-4.1';
}

/**
 * Detect provider from model ID.
 */
function detectProvider(modelId: string): 'openai' | 'anthropic' {
  if (modelId.includes('claude')) return 'anthropic';
  return 'openai';
}

/**
 * Format model ID to human-readable name.
 * Includes badges for preview and plan tier.
 */
function formatModelName(modelId: string): string {
  // Find model in catalog for metadata
  const model = DEFAULT_COPILOT_MODELS.find((m) => m.id === modelId);
  if (model) {
    let name = model.name;
    if (model.preview) name += ' (Preview)';
    return name;
  }

  // Fallback: convert kebab-case to title case
  return modelId
    .split('-')
    .map((word) => word.charAt(0).toUpperCase() + word.slice(1))
    .join(' ');
}