/**
 * Claude Code Integration
 * 
 * Provides seamless integration with Claude Code CLI and IDE extensions.
 * Enables context compaction, subagent spawning, and task orchestration
 * within Claude Code workflows.
 */

import { ContextManager, ContextManagerConfig } from '../core/context-manager';
import { TokenCounter } from '../core/token-counter';
import { Summarizer, SummarizerOptions } from '../core/summarizer';
import { Orchestrator, OrchestratorConfig, Task } from '../core/orchestrator';
import { SubagentSpawner, SubagentType } from '../core/subagent-spawner';
import { MemoryStore } from '../storage/memory-store';

// ============================================================================
// Types
// ============================================================================

export interface ClaudeCodeConfig {
  /** Maximum tokens for context (default: 200000 for Claude models) */
  maxContextTokens?: number;
  /** Reserve tokens for response generation */
  reserveTokens?: number;
  /** Compaction strategy */
  compactionStrategy?: 'sliding-window' | 'summarize-old' | 'priority-retention' | 'hybrid';
  /** Priority keywords for retention */
  priorityKeywords?: string[];
  /** Enable automatic compaction */
  autoCompact?: boolean;
  /** Compaction threshold percentage (0-1) */
  compactionThreshold?: number;
  /** Model identifier for Claude */
  model?: string;
  /** Enable subagent spawning */
  enableSubagents?: boolean;
  /** Max concurrent subagents */
  maxSubagents?: number;
  /** Working directory for Claude Code */
  workingDirectory?: string;
  /** Enable persistent memory */
  persistentMemory?: boolean;
  /** Memory store path */
  memoryStorePath?: string;
}

export interface ClaudeMessage {
  role: 'user' | 'assistant' | 'system';
  content: string;
  metadata?: {
    timestamp?: number;
    tokens?: number;
    priority?: number;
    toolUse?: boolean;
    fileReferences?: string[];
  };
}

export interface ClaudeToolDefinition {
  name: string;
  description: string;
  input_schema: {
    type: 'object';
    properties: Record<string, any>;
    required?: string[];
  };
}

export interface ClaudeCodeSession {
  id: string;
  createdAt: Date;
  lastActivity: Date;
  messageCount: number;
  tokenUsage: number;
  status: 'active' | 'compacted' | 'idle' | 'error';
}

export interface CompactionResult {
  success: boolean;
  tokensBefore: number;
  tokensAfter: number;
  tokensSaved: number;
  messagesRemoved: number;
  summary?: string;
  keyPoints?: string[];
  decisions?: string[];
}

export interface SubagentTask {
  type: SubagentType;
  prompt: string;
  context?: Record<string, any>;
  timeout?: number;
  priority?: 'low' | 'medium' | 'high';
}

export interface SubagentResult {
  success: boolean;
  output: string;
  tokens: number;
  duration: number;
  filesModified?: string[];
  artifacts?: Record<string, any>;
}

// ============================================================================
// Claude Code Integration Class
// ============================================================================

export class ClaudeCodeIntegration {
  private contextManager: ContextManager;
  private tokenCounter: TokenCounter;
  private summarizer: Summarizer;
  private orchestrator: Orchestrator | null = null;
  private subagentSpawner: SubagentSpawner | null = null;
  private memoryStore: MemoryStore | null = null;
  private config: Required<ClaudeCodeConfig>;
  private sessionId: string;
  private messages: ClaudeMessage[] = [];
  private toolDefinitions: ClaudeToolDefinition[] = [];
  private compactionHistory: CompactionResult[] = [];

  constructor(config: ClaudeCodeConfig = {}) {
    this.config = {
      maxContextTokens: config.maxContextTokens ?? 200000,
      reserveTokens: config.reserveTokens ?? 40000,
      compactionStrategy: config.compactionStrategy ?? 'hybrid',
      priorityKeywords: config.priorityKeywords ?? [
        'error', 'important', 'decision', 'critical', 'remember', 'todo', 'fixme'
      ],
      autoCompact: config.autoCompact ?? true,
      compactionThreshold: config.compactionThreshold ?? 0.8,
      model: config.model ?? 'claude-sonnet-4-20250514',
      enableSubagents: config.enableSubagents ?? true,
      maxSubagents: config.maxSubagents ?? 6,
      workingDirectory: config.workingDirectory ?? process.cwd(),
      persistentMemory: config.persistentMemory ?? true,
      memoryStorePath: config.memoryStorePath ?? '.claude-code/memory'
    };

    // Initialize core components
    this.tokenCounter = new TokenCounter(this.config.maxContextTokens);
    this.summarizer = new Summarizer();
    this.contextManager = new ContextManager(
      this.tokenCounter,
      this.summarizer,
      {
        maxTokens: this.config.maxContextTokens - this.config.reserveTokens,
        compactionStrategy: this.config.compactionStrategy,
        priorityKeywords: this.config.priorityKeywords,
        reserveTokens: this.config.reserveTokens
      }
    );

    // Initialize orchestrator if subagents enabled
    if (this.config.enableSubagents) {
      this.orchestrator = new Orchestrator({
        maxAgents: this.config.maxSubagents,
        taskTimeout: 300000,
        retryAttempts: 3
      });
      this.subagentSpawner = new SubagentSpawner();
    }

    // Initialize memory store if persistent
    if (this.config.persistentMemory) {
      this.memoryStore = new MemoryStore(this.config.memoryStorePath);
    }

    this.sessionId = this.generateSessionId();
    this.registerDefaultTools();
  }

  // ============================================================================
  // Session Management
  // ============================================================================

  private generateSessionId(): string {
    return `claude-code-${Date.now()}-${Math.random().toString(36).substr(2, 9)}`;
  }

  getSessionId(): string {
    return this.sessionId;
  }

  getSessionInfo(): ClaudeCodeSession {
    const usage = this.tokenCounter.getUsagePercentage();
    return {
      id: this.sessionId,
      createdAt: new Date(parseInt(this.sessionId.split('-')[2])),
      lastActivity: new Date(),
      messageCount: this.messages.length,
      tokenUsage: this.tokenCounter.getCurrentUsage(),
      status: usage > this.config.compactionThreshold ? 'compacted' : 
              this.messages.length === 0 ? 'idle' : 'active'
    };
  }

  // ============================================================================
  // Message Handling
  // ============================================================================

  /**
   * Add a message to the context
   */
  addMessage(message: ClaudeMessage): void {
    // Estimate tokens for this message
    const tokens = this.tokenCounter.countTokens(message.content);
    message.metadata = {
      ...message.metadata,
      timestamp: message.metadata?.timestamp ?? Date.now(),
      tokens
    };

    this.messages.push(message);
    this.tokenCounter.addUsage(tokens);

    // Add to context manager
    this.contextManager.addMessage({
      role: message.role,
      content: message.content,
      priority: message.metadata?.priority,
      timestamp: message.metadata?.timestamp
    });

    // Check for auto-compaction
    if (this.config.autoCompact && this.needsCompaction()) {
      this.compact();
    }
  }

  /**
   * Get all messages in context
   */
  getMessages(): ClaudeMessage[] {
    return [...this.messages];
  }

  /**
   * Get context for Claude API call
   */
  getContextForAPI(): { messages: ClaudeMessage[]; systemPrompt?: string } {
    const activeContext = this.contextManager.getActiveContext();
    
    const messages: ClaudeMessage[] = activeContext.messages.map(m => ({
      role: m.role as 'user' | 'assistant',
      content: m.content,
      metadata: {
        timestamp: m.timestamp,
        priority: m.priority
      }
    }));

    return {
      messages,
      systemPrompt: activeContext.summary ? 
        `[Previous Context Summary]\n${activeContext.summary}\n\n[End of Summary]` : 
        undefined
    };
  }

  // ============================================================================
  // Context Compaction
  // ============================================================================

  /**
   * Check if compaction is needed
   */
  needsCompaction(): boolean {
    return this.tokenCounter.getUsagePercentage() >= this.config.compactionThreshold;
  }

  /**
   * Perform context compaction
   */
  async compact(): Promise<CompactionResult> {
    const tokensBefore = this.tokenCounter.getCurrentUsage();

    try {
      const result = await this.contextManager.compact();
      
      // Update local messages to match compacted context
      const activeContext = this.contextManager.getActiveContext();
      this.messages = activeContext.messages.map(m => ({
        role: m.role as 'user' | 'assistant',
        content: m.content,
        metadata: {
          timestamp: m.timestamp,
          priority: m.priority
        }
      }));

      // Reset token counter and recalculate
      this.tokenCounter.reset();
      const newTokens = this.messages.reduce(
        (sum, m) => sum + this.tokenCounter.countTokens(m.content),
        0
      );
      this.tokenCounter.addUsage(newTokens);

      const compactionResult: CompactionResult = {
        success: true,
        tokensBefore,
        tokensAfter: this.tokenCounter.getCurrentUsage(),
        tokensSaved: tokensBefore - this.tokenCounter.getCurrentUsage(),
        messagesRemoved: result.messagesRemoved,
        summary: result.summary,
        keyPoints: result.keyPoints,
        decisions: result.decisions
      };

      this.compactionHistory.push(compactionResult);
      return compactionResult;

    } catch (error) {
      return {
        success: false,
        tokensBefore,
        tokensAfter: tokensBefore,
        tokensSaved: 0,
        messagesRemoved: 0
      };
    }
  }

  /**
   * Get compaction history
   */
  getCompactionHistory(): CompactionResult[] {
    return [...this.compactionHistory];
  }

  /**
   * Get current token usage stats
   */
  getTokenStats(): {
    used: number;
    total: number;
    remaining: number;
    percentage: number;
  } {
    return {
      used: this.tokenCounter.getCurrentUsage(),
      total: this.config.maxContextTokens,
      remaining: this.tokenCounter.getRemainingBudget(),
      percentage: this.tokenCounter.getUsagePercentage() * 100
    };
  }

  // ============================================================================
  // Tool Registration
  // ============================================================================

  private registerDefaultTools(): void {
    // Register context management tools
    this.registerTool({
      name: 'compact_context',
      description: 'Compact the conversation context to save tokens while preserving important information',
      input_schema: {
        type: 'object',
        properties: {
          force: {
            type: 'boolean',
            description: 'Force compaction even if threshold not reached'
          }
        }
      }
    });

    // Register subagent tools
    if (this.config.enableSubagents) {
      this.registerTool({
        name: 'spawn_explorer',
        description: 'Spawn an explorer agent to quickly search and navigate the codebase',
        input_schema: {
          type: 'object',
          properties: {
            query: {
              type: 'string',
              description: 'Search query or file pattern to explore'
            }
          },
          required: ['query']
        }
      });

      this.registerTool({
        name: 'spawn_researcher',
        description: 'Spawn a researcher agent to deeply analyze and research a topic',
        input_schema: {
          type: 'object',
          properties: {
            topic: {
              type: 'string',
              description: 'Topic to research'
            },
            depth: {
              type: 'string',
              enum: ['shallow', 'medium', 'deep'],
              description: 'Research depth level'
            }
          },
          required: ['topic']
        }
      });

      this.registerTool({
        name: 'spawn_coder',
        description: 'Spawn a coder agent to implement or modify code',
        input_schema: {
          type: 'object',
          properties: {
            task: {
              type: 'string',
              description: 'Coding task description'
            },
            files: {
              type: 'array',
              items: { type: 'string' },
              description: 'Files to work on'
            }
          },
          required: ['task']
        }
      });

      this.registerTool({
        name: 'spawn_reviewer',
        description: 'Spawn a reviewer agent to review code quality and suggest improvements',
        input_schema: {
          type: 'object',
          properties: {
            files: {
              type: 'array',
              items: { type: 'string' },
              description: 'Files to review'
            },
            focus: {
              type: 'string',
              description: 'Review focus area (security, performance, style, all)'
            }
          },
          required: ['files']
        }
      });
    }
  }

  /**
   * Register a custom tool
   */
  registerTool(tool: ClaudeToolDefinition): void {
    this.toolDefinitions.push(tool);
  }

  /**
   * Get all registered tools
   */
  getTools(): ClaudeToolDefinition[] {
    return [...this.toolDefinitions];
  }

  // ============================================================================
  // Subagent Spawning
  // ============================================================================

  /**
   * Spawn a subagent for a specific task
   */
  async spawnSubagent(task: SubagentTask): Promise<SubagentResult> {
    if (!this.subagentSpawner || !this.orchestrator) {
      throw new Error('Subagents are not enabled in this configuration');
    }

    const startTime = Date.now();

    try {
      // Create subagent
      const agent = this.subagentSpawner.spawn(task.type, {
        taskId: `${this.sessionId}-${task.type}-${Date.now()}`,
        memory: this.memoryStore || undefined
      });

      // Execute task
      const result = await agent.execute({
        prompt: task.prompt,
        ...task.context
      });

      const duration = Date.now() - startTime;
      const outputTokens = this.tokenCounter.countTokens(result.output || '');

      return {
        success: result.success !== false,
        output: result.output || '',
        tokens: outputTokens,
        duration,
        filesModified: result.filesModified,
        artifacts: result.artifacts
      };

    } catch (error) {
      return {
        success: false,
        output: `Subagent error: ${error instanceof Error ? error.message : 'Unknown error'}`,
        tokens: 0,
        duration: Date.now() - startTime
      };
    }
  }

  /**
   * Execute multiple subagent tasks in parallel
   */
  async executeParallelSubagents(tasks: SubagentTask[]): Promise<SubagentResult[]> {
    return Promise.all(tasks.map(task => this.spawnSubagent(task)));
  }

  // ============================================================================
  // Memory Management
  // ============================================================================

  /**
   * Store a value in persistent memory
   */
  async remember(key: string, value: any): Promise<void> {
    if (this.memoryStore) {
      await this.memoryStore.set(`session:${this.sessionId}:${key}`, value);
    }
  }

  /**
   * Retrieve a value from persistent memory
   */
  async recall<T>(key: string): Promise<T | null> {
    if (this.memoryStore) {
      return this.memoryStore.get<T>(`session:${this.sessionId}:${key}`);
    }
    return null;
  }

  /**
   * Store important context for cross-session persistence
   */
  async saveContext(name: string): Promise<void> {
    if (this.memoryStore) {
      await this.memoryStore.set(`context:${name}`, {
        sessionId: this.sessionId,
        messages: this.messages,
        createdAt: Date.now()
      });
    }
  }

  /**
   * Load a previously saved context
   */
  async loadContext(name: string): Promise<boolean> {
    if (this.memoryStore) {
      const saved = await this.memoryStore.get<{
        sessionId: string;
        messages: ClaudeMessage[];
      }>(`context:${name}`);

      if (saved) {
        this.messages = saved.messages;
        this.tokenCounter.reset();
        for (const msg of this.messages) {
          this.tokenCounter.addUsage(this.tokenCounter.countTokens(msg.content));
        }
        return true;
      }
    }
    return false;
  }

  // ============================================================================
  // Utility Methods
  // ============================================================================

  /**
   * Reset the session
   */
  reset(): void {
    this.messages = [];
    this.tokenCounter.reset();
    this.contextManager = new ContextManager(
      this.tokenCounter,
      this.summarizer,
      {
        maxTokens: this.config.maxContextTokens - this.config.reserveTokens,
        compactionStrategy: this.config.compactionStrategy,
        priorityKeywords: this.config.priorityKeywords,
        reserveTokens: this.config.reserveTokens
      }
    );
    this.sessionId = this.generateSessionId();
    this.compactionHistory = [];
  }

  /**
   * Export session data
   */
  exportSession(): {
    sessionId: string;
    config: Required<ClaudeCodeConfig>;
    messages: ClaudeMessage[];
    compactionHistory: CompactionResult[];
    toolDefinitions: ClaudeToolDefinition[];
  } {
    return {
      sessionId: this.sessionId,
      config: this.config,
      messages: this.messages,
      compactionHistory: this.compactionHistory,
      toolDefinitions: this.toolDefinitions
    };
  }

  /**
   * Import session data
   */
  importSession(data: ReturnType<typeof this.exportSession>): void {
    this.sessionId = data.sessionId;
    this.messages = data.messages;
    this.compactionHistory = data.compactionHistory;
    this.toolDefinitions = data.toolDefinitions;
    
    // Rebuild token counter state
    this.tokenCounter.reset();
    for (const msg of this.messages) {
      this.tokenCounter.addUsage(this.tokenCounter.countTokens(msg.content));
    }
  }
}

// ============================================================================
// Factory Function
// ============================================================================

/**
 * Create a Claude Code integration instance with sensible defaults
 */
export function createClaudeCodeIntegration(
  config?: ClaudeCodeConfig
): ClaudeCodeIntegration {
  return new ClaudeCodeIntegration(config);
}

// ============================================================================
// Export
// ============================================================================

export default ClaudeCodeIntegration;