import { OptionValues } from 'commander';
import { query } from '@anthropic-ai/claude-agent-sdk';
import { getClaudePath } from '../shared/settings.js';
import { DatabaseManager } from '../services/sqlite/Database.js';
import { StreamingSessionStore } from '../services/sqlite/StreamingSessionStore.js';
import { migrations } from '../services/sqlite/migrations.js';

/**
 * Generate a session title and subtitle from a user prompt
 * CLI command that uses Agent SDK (like changelog.ts)
 *
 * Can be called in two modes:
 * 1. Standalone: generate-title "user prompt" --json
 * 2. With session: generate-title "user prompt" --session-id <id> --save
 */
export async function generateTitle(prompt: string, options: OptionValues): Promise<void> {
  if (!prompt || prompt.trim().length === 0) {
    console.error(JSON.stringify({
      success: false,
      error: 'Prompt is required'
    }));
    process.exit(1);
  }

  // If --session-id provided, validate that session exists
  let streamingStore: StreamingSessionStore | null = null;
  let sessionRecord = null;

  if (options.sessionId) {
    try {
      const dbManager = DatabaseManager.getInstance();
      for (const migration of migrations) {
        dbManager.registerMigration(migration);
      }
      const db = await dbManager.initialize();
      streamingStore = new StreamingSessionStore(db);

      sessionRecord = streamingStore.getByClaudeSessionId(options.sessionId);
      if (!sessionRecord) {
        console.error(JSON.stringify({
          success: false,
          error: `Session not found: ${options.sessionId}`
        }));
        process.exit(1);
      }
    } catch (error: any) {
      console.error(JSON.stringify({
        success: false,
        error: `Database error: ${error.message}`
      }));
      process.exit(1);
    }
  }

  const systemPrompt = `You are a title and subtitle generator for claude-mem session metadata.

Your job is to analyze a user's request and generate:
1. A concise title (3-8 words)
2. A one-sentence subtitle (max 20 words)

TITLE GUIDELINES:
- 3-8 words maximum
- Scannable and clear
- Captures the core action or topic
- Professional and informative
- Examples:
  * "Dark Mode Implementation"
  * "Authentication Bug Fix"
  * "API Rate Limiting Setup"
  * "React Component Refactoring"

SUBTITLE GUIDELINES:
- One sentence, max 20 words
- Descriptive and specific
- Focus on the outcome or benefit
- Use active voice when possible
- Examples:
  * "Adding theme toggle and dark color scheme support to the application"
  * "Resolving login timeout issue affecting user session persistence"
  * "Implementing request throttling to prevent API quota exhaustion"

OUTPUT FORMAT:
You must output EXACTLY two lines:
Line 1: Title only (no prefix, no quotes)
Line 2: Subtitle only (no prefix, no quotes)

EXAMPLE:

User request: "Help me add dark mode to my app"

Output:
Dark Mode Implementation
Adding theme toggle and dark color scheme support to the application

USER REQUEST:
${prompt}

Now generate the title and subtitle (two lines exactly):`;

  try {
    const response = await query({
      prompt: systemPrompt,
      options: {
        allowedTools: [],
        pathToClaudeCodeExecutable: getClaudePath()
      }
    });

    // Extract text from response (same pattern as changelog.ts)
    let fullResponse = '';
    if (response && typeof response === 'object' && Symbol.asyncIterator in response) {
      for await (const message of response) {
        if (message?.type === 'assistant' && message?.message?.content) {
          const content = message.message.content;
          if (typeof content === 'string') {
            fullResponse += content;
          } else if (Array.isArray(content)) {
            for (const block of content) {
              if (block.type === 'text' && block.text) {
                fullResponse += block.text;
              }
            }
          }
        }
      }
    }

    // Parse the response - expecting exactly 2 lines
    const lines = fullResponse.trim().split('\n').filter(line => line.trim().length > 0);

    if (lines.length < 2) {
      console.error(JSON.stringify({
        success: false,
        error: 'Could not generate title and subtitle',
        response: fullResponse
      }));
      process.exit(1);
    }

    const title = lines[0].trim();
    const subtitle = lines[1].trim();

    // If --save and we have a session, update the database
    if (options.save && streamingStore && sessionRecord) {
      try {
        streamingStore.update(sessionRecord.id, {
          title,
          subtitle
        });
      } catch (error: any) {
        console.error(JSON.stringify({
          success: false,
          error: `Failed to save title: ${error.message}`
        }));
        process.exit(1);
      }
    }

    // Output format depends on options
    if (options.json) {
      console.log(JSON.stringify({
        success: true,
        title,
        subtitle,
        sessionId: sessionRecord?.claude_session_id
      }, null, 2));
    } else if (options.oneline) {
      console.log(`${title} - ${subtitle}`);
    } else {
      console.log(title);
      console.log(subtitle);
    }

  } catch (error: any) {
    console.error(JSON.stringify({
      success: false,
      error: error.message || 'Unknown error generating title'
    }));
    process.exit(1);
  }
}