/**
 * Viking Adapter - ZCLAW ↔ OpenViking Integration Layer
 *
 * Maps ZCLAW agent concepts (memories, identity, skills) to OpenViking's
 * viking:// URI namespace. Provides high-level operations for:
 * - User memory management (preferences, facts, history)
 * - Agent memory management (lessons, patterns, tool tips)
 * - L0/L1/L2 layered context building (token-efficient)
 * - Session memory extraction (auto-learning)
 * - Identity file synchronization
 * - Retrieval trace capture (debuggability)
 *
 * Supports three modes:
 * - local: Manages a local OpenViking server (privacy-first, data stays local)
 * - sidecar: Uses OpenViking CLI via Tauri commands (direct CLI integration)
 * - remote: Uses OpenViking HTTP Server (connects to external server)
 *
 * For privacy-conscious users, use 'local' mode which ensures all data
 * stays on the local machine in ~/.openviking/
 */

import {
  VikingHttpClient,
  type FindResult,
  type RetrievalTrace,
  type ExtractedMemory,
  type SessionExtractionResult,
  type ContextLevel,
  type VikingEntry,
  type VikingTreeNode,
} from './viking-client';
import {
  getVikingServerManager,
  type VikingServerStatus,
} from './viking-server-manager';

// Tauri invoke import (safe to import even if not in Tauri context)
let invoke: ((cmd: string, args?: Record<string, unknown>) => Promise<unknown>) | null = null;

try {
  // Dynamic import for Tauri API
  // eslint-disable-next-line @typescript-eslint/no-var-requires
  invoke = require('@tauri-apps/api/core').invoke;
} catch {
  // Not in Tauri context, invoke will be null
  console.log('[VikingAdapter] Not in Tauri context, sidecar mode unavailable');
}

// === Types ===

export interface MemoryResult {
  uri: string;
  content: string;
  score: number;
  level: ContextLevel;
  category: string;
  tags?: string[];
}

export interface EnhancedContext {
  systemPromptAddition: string;
  memories: MemoryResult[];
  totalTokens: number;
  tokensByLevel: { L0: number; L1: number; L2: number };
  trace?: RetrievalTrace;
}

export interface MemorySaveResult {
  uri: string;
  status: string;
}

export interface ExtractionResult {
  saved: number;
  userMemories: number;
  agentMemories: number;
  details: ExtractedMemory[];
}

export interface IdentityFile {
  name: string;
  content: string;
  lastModified?: string;
}

export interface IdentityChangeProposal {
  file: string;
  currentContent: string;
  suggestedContent: string;
  reason: string;
  timestamp: string;
}

export interface VikingAdapterConfig {
  serverUrl: string;
  defaultAgentId: string;
  maxContextTokens: number;
  l0Limit: number;
  l1Limit: number;
  minRelevanceScore: number;
  enableTrace: boolean;
  mode?: VikingMode;
}

const DEFAULT_CONFIG: VikingAdapterConfig = {
  serverUrl: 'http://localhost:1933',
  defaultAgentId: 'zclaw-main',
  maxContextTokens: 8000,
  l0Limit: 30,
  l1Limit: 15,
  minRelevanceScore: 0.5,
  enableTrace: true,
};

// === URI Helpers ===

const VIKING_NS = {
  userMemories: 'viking://user/memories',
  userPreferences: 'viking://user/memories/preferences',
  userFacts: 'viking://user/memories/facts',
  userHistory: 'viking://user/memories/history',
  agentBase: (agentId: string) => `viking://agent/${agentId}`,
  agentIdentity: (agentId: string) => `viking://agent/${agentId}/identity`,
  agentMemories: (agentId: string) => `viking://agent/${agentId}/memories`,
  agentLessons: (agentId: string) => `viking://agent/${agentId}/memories/lessons_learned`,
  agentPatterns: (agentId: string) => `viking://agent/${agentId}/memories/task_patterns`,
  agentToolTips: (agentId: string) => `viking://agent/${agentId}/memories/tool_tips`,
  agentSkills: (agentId: string) => `viking://agent/${agentId}/skills`,
  sharedKnowledge: 'viking://agent/shared/common_knowledge',
  resources: 'viking://resources',
} as const;

// === Rough Token Estimator ===

function estimateTokens(text: string): number {
  // ~1.5 tokens per CJK character, ~0.75 tokens per English word
  const cjkChars = (text.match(/[\u4e00-\u9fff\u3400-\u4dbf]/g) || []).length;
  const otherChars = text.length - cjkChars;
  return Math.ceil(cjkChars * 1.5 + otherChars * 0.4);
}

// === Mode Type ===

export type VikingMode = 'local' | 'sidecar' | 'remote' | 'auto';

// === Adapter Implementation ===

export class VikingAdapter {
  private client: VikingHttpClient;
  private config: VikingAdapterConfig;
  private lastTrace: RetrievalTrace | null = null;
  private mode: VikingMode;
  private resolvedMode: 'local' | 'sidecar' | 'remote' | null = null;
  private serverManager = getVikingServerManager();

  constructor(config?: Partial<VikingAdapterConfig>) {
    this.config = { ...DEFAULT_CONFIG, ...config };
    this.client = new VikingHttpClient(this.config.serverUrl);
    this.mode = config?.mode ?? 'auto';
  }

  // === Mode Detection ===

  private async detectMode(): Promise<'local' | 'sidecar' | 'remote'> {
    if (this.resolvedMode) {
      return this.resolvedMode;
    }

    if (this.mode === 'local') {
      this.resolvedMode = 'local';
      return 'local';
    }

    if (this.mode === 'sidecar') {
      this.resolvedMode = 'sidecar';
      return 'sidecar';
    }

    if (this.mode === 'remote') {
      this.resolvedMode = 'remote';
      return 'remote';
    }

    // Auto mode: try local server first (privacy-first), then sidecar, then remote
    // 1. Check if local server is already running or can be started
    if (invoke) {
      try {
        const status = await this.serverManager.getStatus();
        if (status.running) {
          console.log('[VikingAdapter] Using local mode (OpenViking local server already running)');
          this.resolvedMode = 'local';
          return 'local';
        }

        // Try to start local server
        const started = await this.serverManager.ensureRunning();
        if (started) {
          console.log('[VikingAdapter] Using local mode (OpenViking local server started)');
          this.resolvedMode = 'local';
          return 'local';
        }
      } catch {
        console.log('[VikingAdapter] Local server not available, trying sidecar');
      }
    }

    // 2. Try sidecar mode
    if (invoke) {
      try {
        const status = await invoke('viking_status') as { available: boolean };
        if (status.available) {
          console.log('[VikingAdapter] Using sidecar mode (OpenViking CLI)');
          this.resolvedMode = 'sidecar';
          return 'sidecar';
        }
      } catch {
        console.log('[VikingAdapter] Sidecar mode not available, trying remote');
      }
    }

    // 3. Try remote mode
    if (await this.client.isAvailable()) {
      console.log('[VikingAdapter] Using remote mode (OpenViking Server)');
      this.resolvedMode = 'remote';
      return 'remote';
    }

    console.warn('[VikingAdapter] No Viking backend available');
    return 'remote'; // Default fallback
  }

  getMode(): 'local' | 'sidecar' | 'remote' | null {
    return this.resolvedMode;
  }

  // === Connection ===

  async isConnected(): Promise<boolean> {
    const mode = await this.detectMode();

    if (mode === 'local') {
      const status = await this.serverManager.getStatus();
      return status.running;
    }

    if (mode === 'sidecar') {
      try {
        if (!invoke) return false;
        const status = await invoke('viking_status') as { available: boolean };
        return status.available;
      } catch {
        return false;
      }
    }

    return this.client.isAvailable();
  }

  // === Server Management (for local mode) ===

  /**
   * Get the local server status (for local mode)
   */
  async getLocalServerStatus(): Promise<VikingServerStatus> {
    return this.serverManager.getStatus();
  }

  /**
   * Start the local server (for local mode)
   */
  async startLocalServer(): Promise<VikingServerStatus> {
    return this.serverManager.start();
  }

  /**
   * Stop the local server (for local mode)
   */
  async stopLocalServer(): Promise<void> {
    return this.serverManager.stop();
  }

  getLastTrace(): RetrievalTrace | null {
    return this.lastTrace;
  }

  // === User Memory Operations ===

  async saveUserPreference(
    key: string,
    value: string
  ): Promise<MemorySaveResult> {
    const uri = `${VIKING_NS.userPreferences}/${sanitizeKey(key)}`;
    return this.client.addResource(uri, value, {
      metadata: { type: 'preference', key, updated_at: new Date().toISOString() },
      wait: true,
    });
  }

  async saveUserFact(
    category: string,
    content: string,
    tags?: string[]
  ): Promise<MemorySaveResult> {
    const id = `${Date.now()}_${Math.random().toString(36).slice(2, 6)}`;
    const uri = `${VIKING_NS.userFacts}/${sanitizeKey(category)}/${id}`;
    return this.client.addResource(uri, content, {
      metadata: {
        type: 'fact',
        category,
        tags: (tags || []).join(','),
        created_at: new Date().toISOString(),
      },
      wait: true,
    });
  }

  async searchUserMemories(
    query: string,
    limit: number = 10
  ): Promise<MemoryResult[]> {
    const results = await this.client.find(query, {
      scope: VIKING_NS.userMemories,
      limit,
      level: 'L1',
      minScore: this.config.minRelevanceScore,
    });
    return results.map(toMemoryResult);
  }

  async getUserPreferences(): Promise<VikingEntry[]> {
    try {
      return await this.client.ls(VIKING_NS.userPreferences);
    } catch {
      return [];
    }
  }

  // === Agent Memory Operations ===

  async saveAgentLesson(
    agentId: string,
    lesson: string,
    tags?: string[]
  ): Promise<MemorySaveResult> {
    const id = `${Date.now()}_${Math.random().toString(36).slice(2, 6)}`;
    const uri = `${VIKING_NS.agentLessons(agentId)}/${id}`;
    return this.client.addResource(uri, lesson, {
      metadata: {
        type: 'lesson',
        tags: (tags || []).join(','),
        agent_id: agentId,
        created_at: new Date().toISOString(),
      },
      wait: true,
    });
  }

  async saveAgentPattern(
    agentId: string,
    pattern: string,
    tags?: string[]
  ): Promise<MemorySaveResult> {
    const id = `${Date.now()}_${Math.random().toString(36).slice(2, 6)}`;
    const uri = `${VIKING_NS.agentPatterns(agentId)}/${id}`;
    return this.client.addResource(uri, pattern, {
      metadata: {
        type: 'pattern',
        tags: (tags || []).join(','),
        agent_id: agentId,
        created_at: new Date().toISOString(),
      },
      wait: true,
    });
  }

  async saveAgentToolTip(
    agentId: string,
    tip: string,
    toolName: string
  ): Promise<MemorySaveResult> {
    const uri = `${VIKING_NS.agentToolTips(agentId)}/${sanitizeKey(toolName)}`;
    return this.client.addResource(uri, tip, {
      metadata: {
        type: 'tool_tip',
        tool: toolName,
        agent_id: agentId,
        updated_at: new Date().toISOString(),
      },
      wait: true,
    });
  }

  async searchAgentMemories(
    agentId: string,
    query: string,
    limit: number = 10
  ): Promise<MemoryResult[]> {
    const results = await this.client.find(query, {
      scope: VIKING_NS.agentMemories(agentId),
      limit,
      level: 'L1',
      minScore: this.config.minRelevanceScore,
    });
    return results.map(toMemoryResult);
  }

  // === Identity File Management ===

  async syncIdentityToViking(
    agentId: string,
    fileName: string,
    content: string
  ): Promise<void> {
    const uri = `${VIKING_NS.agentIdentity(agentId)}/${sanitizeKey(fileName.replace('.md', ''))}`;
    await this.client.addResource(uri, content, {
      metadata: {
        type: 'identity',
        file: fileName,
        agent_id: agentId,
        synced_at: new Date().toISOString(),
      },
      wait: true,
    });
  }

  async getIdentityFromViking(
    agentId: string,
    fileName: string
  ): Promise<string> {
    const uri = `${VIKING_NS.agentIdentity(agentId)}/${sanitizeKey(fileName.replace('.md', ''))}`;
    return this.client.readContent(uri, 'L2');
  }

  async proposeIdentityChange(
    agentId: string,
    proposal: IdentityChangeProposal
  ): Promise<MemorySaveResult> {
    const id = `${Date.now()}`;
    const uri = `${VIKING_NS.agentIdentity(agentId)}/changelog/${id}`;
    const content = [
      `# Identity Change Proposal`,
      `**File**: ${proposal.file}`,
      `**Reason**: ${proposal.reason}`,
      `**Timestamp**: ${proposal.timestamp}`,
      '',
      '## Current Content',
      '```',
      proposal.currentContent,
      '```',
      '',
      '## Suggested Content',
      '```',
      proposal.suggestedContent,
      '```',
    ].join('\n');

    return this.client.addResource(uri, content, {
      metadata: {
        type: 'identity_change_proposal',
        file: proposal.file,
        status: 'pending',
        agent_id: agentId,
      },
      wait: true,
    });
  }

  // === Core: Context Building (L0/L1/L2 layered loading) ===

  async buildEnhancedContext(
    userMessage: string,
    agentId: string,
    options?: { maxTokens?: number; includeTrace?: boolean }
  ): Promise<EnhancedContext> {
    const maxTokens = options?.maxTokens ?? this.config.maxContextTokens;
    const includeTrace = options?.includeTrace ?? this.config.enableTrace;

    const tokensByLevel = { L0: 0, L1: 0, L2: 0 };

    // Step 1: L0 fast scan across user + agent memories
    const [userL0, agentL0] = await Promise.all([
      this.client.find(userMessage, {
        scope: VIKING_NS.userMemories,
        level: 'L0',
        limit: this.config.l0Limit,
      }).catch(() => [] as FindResult[]),
      this.client.find(userMessage, {
        scope: VIKING_NS.agentMemories(agentId),
        level: 'L0',
        limit: this.config.l0Limit,
      }).catch(() => [] as FindResult[]),
    ]);

    const allL0 = [...userL0, ...agentL0];
    for (const r of allL0) {
      tokensByLevel.L0 += estimateTokens(r.content);
    }

    // Step 2: Filter high-relevance items, load L1
    const relevant = allL0
      .filter(r => r.score >= this.config.minRelevanceScore)
      .sort((a, b) => b.score - a.score)
      .slice(0, this.config.l1Limit);

    const l1Results: MemoryResult[] = [];
    let tokenBudget = maxTokens;

    for (const item of relevant) {
      try {
        const l1Content = await this.client.readContent(item.uri, 'L1');
        const tokens = estimateTokens(l1Content);

        if (tokenBudget - tokens < 500) break; // Keep 500 token reserve

        l1Results.push({
          uri: item.uri,
          content: l1Content,
          score: item.score,
          level: 'L1',
          category: extractCategory(item.uri),
        });

        tokenBudget -= tokens;
        tokensByLevel.L1 += tokens;
      } catch {
        // Skip items that fail to load
      }
    }

    // Step 3: Build retrieval trace (if enabled)
    let trace: RetrievalTrace | undefined;
    if (includeTrace) {
      trace = {
        query: userMessage,
        steps: allL0.map(r => ({
          uri: r.uri,
          score: r.score,
          action: r.score >= this.config.minRelevanceScore ? 'entered' as const : 'skipped' as const,
          level: 'L0' as ContextLevel,
        })),
        totalTokensUsed: maxTokens - tokenBudget,
        tokensByLevel,
        duration: 0, // filled by caller if timing
      };
      this.lastTrace = trace;
    }

    // Step 4: Format as system prompt addition
    const systemPromptAddition = formatMemoriesForPrompt(l1Results);

    return {
      systemPromptAddition,
      memories: l1Results,
      totalTokens: maxTokens - tokenBudget,
      tokensByLevel,
      trace,
    };
  }

  // === Session Memory Extraction ===

  async extractAndSaveMemories(
    messages: Array<{ role: string; content: string }>,
    agentId: string,
    _conversationId?: string
  ): Promise<ExtractionResult> {
    const sessionContent = messages
      .map(m => `[${m.role}]: ${m.content}`)
      .join('\n\n');

    let extraction: SessionExtractionResult;
    try {
      extraction = await this.client.extractMemories(sessionContent, agentId);
    } catch (err) {
      // If OpenViking extraction API is not available, use fallback
      console.warn('[VikingAdapter] Session extraction failed, using fallback:', err);
      return { saved: 0, userMemories: 0, agentMemories: 0, details: [] };
    }

    let userCount = 0;
    let agentCount = 0;

    for (const memory of extraction.memories) {
      try {
        if (memory.category === 'user_preference') {
          const key = memory.tags[0] || `pref_${Date.now()}`;
          await this.saveUserPreference(key, memory.content);
          userCount++;
        } else if (memory.category === 'user_fact') {
          const category = memory.tags[0] || 'general';
          await this.saveUserFact(category, memory.content, memory.tags);
          userCount++;
        } else if (memory.category === 'agent_lesson') {
          await this.saveAgentLesson(agentId, memory.content, memory.tags);
          agentCount++;
        } else if (memory.category === 'agent_pattern') {
          await this.saveAgentPattern(agentId, memory.content, memory.tags);
          agentCount++;
        }
      } catch (err) {
        console.warn('[VikingAdapter] Failed to save memory:', memory.suggestedUri, err);
      }
    }

    return {
      saved: userCount + agentCount,
      userMemories: userCount,
      agentMemories: agentCount,
      details: extraction.memories,
    };
  }

  // === Memory Browsing ===

  async browseMemories(
    path: string = 'viking://'
  ): Promise<VikingEntry[]> {
    try {
      return await this.client.ls(path);
    } catch {
      return [];
    }
  }

  async getMemoryTree(
    agentId: string,
    depth: number = 2
  ): Promise<VikingTreeNode | null> {
    try {
      return await this.client.tree(VIKING_NS.agentBase(agentId), depth);
    } catch {
      return null;
    }
  }

  async deleteMemory(uri: string): Promise<void> {
    await this.client.removeResource(uri);
  }

  // === Memory Statistics ===

  async getMemoryStats(agentId: string): Promise<{
    totalEntries: number;
    userMemories: number;
    agentMemories: number;
    categories: Record<string, number>;
  }> {
    const [userEntries, agentEntries] = await Promise.all([
      this.client.ls(VIKING_NS.userMemories).catch(() => []),
      this.client.ls(VIKING_NS.agentMemories(agentId)).catch(() => []),
    ]);

    const categories: Record<string, number> = {};
    for (const entry of [...userEntries, ...agentEntries]) {
      const cat = extractCategory(entry.uri);
      categories[cat] = (categories[cat] || 0) + 1;
    }

    return {
      totalEntries: userEntries.length + agentEntries.length,
      userMemories: userEntries.length,
      agentMemories: agentEntries.length,
      categories,
    };
  }
}

// === Utility Functions ===

function sanitizeKey(key: string): string {
  return key
    .toLowerCase()
    .replace(/[^a-z0-9\u4e00-\u9fff_-]/g, '_')
    .replace(/_+/g, '_')
    .replace(/^_|_$/g, '');
}

function extractCategory(uri: string): string {
  const parts = uri.replace('viking://', '').split('/');
  // Return the 3rd segment as category (e.g., "preferences" from viking://user/memories/preferences/...)
  return parts[2] || parts[1] || 'unknown';
}

function toMemoryResult(result: FindResult): MemoryResult {
  return {
    uri: result.uri,
    content: result.content,
    score: result.score,
    level: result.level,
    category: extractCategory(result.uri),
  };
}

function formatMemoriesForPrompt(memories: MemoryResult[]): string {
  if (memories.length === 0) return '';

  const userMemories = memories.filter(m => m.uri.startsWith('viking://user/'));
  const agentMemories = memories.filter(m => m.uri.startsWith('viking://agent/'));

  const sections: string[] = [];

  if (userMemories.length > 0) {
    sections.push('## 用户记忆');
    for (const m of userMemories) {
      sections.push(`- [${m.category}] ${m.content}`);
    }
  }

  if (agentMemories.length > 0) {
    sections.push('## Agent 经验');
    for (const m of agentMemories) {
      sections.push(`- [${m.category}] ${m.content}`);
    }
  }

  return sections.join('\n');
}

// === Singleton factory ===

let _instance: VikingAdapter | null = null;

export function getVikingAdapter(config?: Partial<VikingAdapterConfig>): VikingAdapter {
  if (!_instance || config) {
    _instance = new VikingAdapter(config);
  }
  return _instance;
}

export function resetVikingAdapter(): void {
  _instance = null;
}

export { VIKING_NS };