import { BaseFormatter } from '../classes.baseformatter.js';
import type { IPlannedChange } from '../interfaces.format.js';
import * as plugins from '../mod.plugins.js';
import * as paths from '../../paths.js';
import { logger } from '../../gitzone.logging.js';

export class GitignoreFormatter extends BaseFormatter {
  get name(): string {
    return 'gitignore';
  }

  /**
   * Read the standard gitignore template from the asset file,
   * stripping the YAML frontmatter.
   */
  private async getStandardTemplate(): Promise<string> {
    const templatePath = plugins.path.join(paths.templatesDir, 'gitignore', '_gitignore');
    const raw = (await plugins.smartfs
      .file(templatePath)
      .encoding('utf8')
      .read()) as string;

    // Strip YAML frontmatter (---\n...\n---)
    const frontmatterEnd = raw.indexOf('---', 3);
    if (frontmatterEnd !== -1) {
      return raw.slice(frontmatterEnd + 3).trimStart();
    }
    return raw;
  }

  async analyze(): Promise<IPlannedChange[]> {
    const changes: IPlannedChange[] = [];
    const gitignorePath = '.gitignore';

    const standardTemplate = await this.getStandardTemplate();

    // Check if file exists and extract custom content
    let customContent = '';
    const exists = await plugins.smartfs.file(gitignorePath).exists();

    if (exists) {
      const existingContent = (await plugins.smartfs
        .file(gitignorePath)
        .encoding('utf8')
        .read()) as string;

      // Extract custom section content
      const customMarkers = ['#------# custom', '# custom'];
      for (const marker of customMarkers) {
        const splitResult = existingContent.split(marker);
        if (splitResult.length > 1) {
          customContent = splitResult[1].trim();
          break;
        }
      }
    }

    // Compute new content
    let newContent = standardTemplate;
    if (customContent) {
      newContent = standardTemplate + '\n' + customContent + '\n';
    } else {
      newContent = standardTemplate + '\n';
    }

    // Read current content to compare
    let currentContent = '';
    if (exists) {
      currentContent = (await plugins.smartfs
        .file(gitignorePath)
        .encoding('utf8')
        .read()) as string;
    }

    if (!exists) {
      changes.push({
        type: 'create',
        path: gitignorePath,
        module: this.name,
        description: 'Create .gitignore',
        content: newContent,
      });
    } else if (newContent !== currentContent) {
      changes.push({
        type: 'modify',
        path: gitignorePath,
        module: this.name,
        description: 'Update .gitignore (preserving custom section)',
        content: newContent,
      });
    }

    return changes;
  }

  async applyChange(change: IPlannedChange): Promise<void> {
    if (!change.content) return;

    if (change.type === 'create') {
      await this.createFile(change.path, change.content);
      logger.log('info', 'Created .gitignore');
    } else if (change.type === 'modify') {
      await this.modifyFile(change.path, change.content);
      logger.log('info', 'Updated .gitignore (preserved custom section)');
    }
  }
}