import logger from '../utils/logger.js';
import { sample, shuffle } from 'lodash-es';

class SDLCManager {
  constructor(githubService, aiProvider, codeGenerator, schedule) {
    this.github = githubService;
    this.ai = aiProvider;
    this.codeGen = codeGenerator;
    this.schedule = schedule;
    this.state = {
      currentPhase: 'idle',
      activeIssues: [],
      activeBranches: [],
      activePRs: [],
      sessionCommits: 0,
    };
  }

  async runCycle() {
    if (!this.schedule.isWorkHours()) {
      logger.info('Outside work hours, skipping cycle');
      return;
    }

    const energy = this.schedule.getEnergyLevel();
    logger.info(`Starting SDLC cycle (energy: ${(energy * 100).toFixed(0)}%)`);

    await this._syncState();

    const action = this._decideNextAction();
    logger.info(`Decided action: ${action.type}`);

    try {
      switch (action.type) {
        case 'create_issue':
          await this._createIssue();
          break;
        case 'work_on_issue':
          await this._workOnIssue(action.issue);
          break;
        case 'review_pr':
          await this._reviewPR(action.pr);
          break;
        case 'merge_pr':
          await this._mergePR(action.pr);
          break;
        case 'fix_review_comment':
          await this._fixReviewComment(action.pr);
          break;
        case 'close_issue':
          await this._closeIssue(action.issue);
          break;
        default:
          logger.info('No actionable task, waiting');
      }
    } catch (error) {
      logger.error(`SDLC cycle error: ${error.message}`);
    }

    this.state.sessionCommits++;
  }

  async _syncState() {
    const [issues, prs] = await Promise.all([
      this.github.listIssues('open'),
      this.github.listPullRequests('open'),
    ]);

    this.state.activeIssues = issues;
    this.state.activePRs = prs;

    logger.debug(`Synced state: ${issues.length} open issues, ${prs.length} open PRs`);
  }

  _decideNextAction() {
    const { activeIssues, activePRs, sessionCommits } = this.state;

    const maxCommits = this.schedule.config?.activity?.maxCommitsPerSession || 8;
    if (sessionCommits >= maxCommits) {
      return { type: 'idle', reason: 'max commits reached' };
    }

    const openPRs = activePRs.filter(pr => pr.state === 'open');

    if (openPRs.length > 0 && Math.random() < 0.3) {
      const pr = sample(openPRs);

      if (Math.random() < 0.4) {
        return { type: 'review_pr', pr };
      }

      if (Math.random() < 0.3) {
        return { type: 'merge_pr', pr };
      }

      if (Math.random() < 0.2) {
        return { type: 'fix_review_comment', pr };
      }
    }

    const workableIssues = activeIssues.filter(
      issue => !issue.labels?.some(l => l.name === 'in-progress')
    );

    if (workableIssues.length > 0 && Math.random() < 0.6) {
      return { type: 'work_on_issue', issue: sample(workableIssues) };
    }

    if (Math.random() < 0.5) {
      return { type: 'create_issue' };
    }

    const closableIssues = activeIssues.filter(
      issue => issue.labels?.some(l => l.name === 'done' || l.name === 'resolved')
    );

    if (closableIssues.length > 0) {
      return { type: 'close_issue', issue: sample(closableIssues) };
    }

    return { type: 'create_issue' };
  }

  async _createIssue() {
    logger.info('Creating new issue');

    const projectContext = await this._getProjectContext();
    const title = await this.ai.generateIssueTitle(projectContext);
    const body = await this.ai.generateIssueBody(title, projectContext);

    const labels = this._generateIssueLabels(title);

    const issue = await this.github.createIssue(title, body, labels);
    this.state.activeIssues.push(issue);

    logger.info(`Created issue #${issue.number}: ${title}`);
  }

  async _workOnIssue(issue) {
    logger.info(`Working on issue #${issue.number}: ${issue.title}`);

    await this.github.addLabels(issue.number, ['in-progress']);

    const branchName = this._generateBranchName(issue.title);

    try {
      await this.github.createBranch(branchName);
    } catch (error) {
      logger.warn(`Branch ${branchName} exists, using it`);
    }

    this.state.activeBranches.push(branchName);

    const structure = this.codeGen.generateProjectStructure();
    const numFiles = Math.min(
      structure.files.length,
      (this.schedule.config?.activity?.maxFilesPerCommit || 3)
    );

    const filesToCreate = shuffle(structure.files).slice(0, numFiles);

    for (const file of filesToCreate) {
      await this._createFileInBranch(file, branchName, issue);
    }

    const prTitle = this._generatePRTitle(issue.title, structure.name);
    const prBody = await this.ai.generatePRDescription(
      branchName,
      `Implemented ${structure.name} functionality for issue #${issue.number}`
    );

    const pr = await this.github.createPullRequest(prTitle, prBody, branchName);
    this.state.activePRs.push(pr);

    await this.github.addLabels(issue.number, ['done']);

    logger.info(`Created PR #${pr.number} for issue #${issue.number}`);
  }

  async _createFileInBranch(file, branchName, issue) {
    const content = this.codeGen.generateFileContent(file.type, {
      issue: issue.title,
      project: await this._getProjectContext(),
    });

    const commitMessage = this.codeGen.generateCommitMessageForFile(file.path, file.type);

    await this.github.createOrUpdateFile(
      file.path,
      content,
      commitMessage,
      branchName
    );

    logger.info(`Created ${file.path} on ${branchName}`);
  }

  async _reviewPR(pr) {
    logger.info(`Reviewing PR #${pr.number}: ${pr.title}`);

    const files = await this.github.getPullRequestFiles(pr.number);

    if (files.length === 0) {
      return;
    }

    const fileToReview = sample(files);

    try {
      const content = await this._getFileContent(fileToReview);
      const comment = await this.ai.generateReviewComment(
        content || 'Code review pending',
        fileToReview.filename
      );

      const reviewType = this._decideReviewType();

      if (reviewType === 'comment') {
        await this.github.addPullRequestComment(pr.number, comment);
      } else {
        await this.github.addPullRequestReview(
          pr.number,
          reviewType,
          comment,
          pr.head?.sha
        );
      }

      logger.info(`Added ${reviewType} review to PR #${pr.number}`);
    } catch (error) {
      logger.error(`Review error: ${error.message}`);
    }
  }

  async _mergePR(pr) {
    logger.info(`Merging PR #${pr.number}`);

    try {
      await this.github.mergePullRequest(pr.number);

      if (pr.head?.ref) {
        await this.github.deleteBranch(pr.head.ref);
      }

      this.state.activePRs = this.state.activePRs.filter(p => p.number !== pr.number);
    } catch (error) {
      logger.error(`Merge error: ${error.message}`);
    }
  }

  async _fixReviewComment(pr) {
    logger.info(`Fixing review comments on PR #${pr.number}`);

    const files = await this.github.getPullRequestFiles(pr.number);

    if (files.length === 0) return;

    const file = sample(files);
    const content = this.codeGen.generateFileContent(file.type || 'utility', {
      fix: true,
      original: file.filename,
    });

    await this.github.createOrUpdateFile(
      file.filename || file.path,
      content,
      'fix: address review comments',
      pr.head?.ref || 'main'
    );

    await this.github.addPullRequestComment(
      pr.number,
      "Thanks for the review! I've addressed the feedback in this commit."
    );
  }

  async _closeIssue(issue) {
    logger.info(`Closing issue #${issue.number}`);
    await this.github.closeIssue(issue.number);
    this.state.activeIssues = this.state.activeIssues.filter(i => i.number !== issue.number);
  }

  _generateBranchName(issueTitle) {
    const sanitized = issueTitle
      .toLowerCase()
      .replace(/[^a-z0-9\s-]/g, '')
      .replace(/\s+/g, '-')
      .replace(/-+/g, '-')
      .slice(0, 50);

    const prefix = this._getBranchPrefix(issueTitle);
    return `${prefix}/${sanitized}`;
  }

  _getBranchPrefix(title) {
    const lower = title.toLowerCase();
    if (lower.includes('add') || lower.includes('implement') || lower.includes('new')) return 'feat';
    if (lower.includes('fix') || lower.includes('bug') || lower.includes('error')) return 'fix';
    if (lower.includes('refactor') || lower.includes('clean') || lower.includes('improve')) return 'refactor';
    if (lower.includes('test') || lower.includes('coverage')) return 'test';
    if (lower.includes('doc') || lower.includes('readme')) return 'docs';
    return 'chore';
  }

  _generatePRTitle(issueTitle, featureName) {
    const prefix = this._getBranchPrefix(issueTitle);
    return `${prefix}: ${issueTitle.charAt(0).toLowerCase() + issueTitle.slice(1)}`;
  }

  _generateIssueLabels(title) {
    const labels = [];
    const lower = title.toLowerCase();

    if (lower.includes('add') || lower.includes('implement') || lower.includes('new')) {
      labels.push('enhancement');
    }
    if (lower.includes('fix') || lower.includes('bug') || lower.includes('error')) {
      labels.push('bug');
    }
    if (lower.includes('performance') || lower.includes('optimize')) {
      labels.push('performance');
    }
    if (lower.includes('security') || lower.includes('auth')) {
      labels.push('security');
    }

    if (labels.length === 0) {
      labels.push(sample(['enhancement', 'maintenance', 'task']));
    }

    return labels;
  }

  _decideReviewType() {
    const rand = Math.random();
    if (rand < 0.6) return 'comment';
    if (rand < 0.85) return 'approve';
    return 'request_changes';
  }

  async _getProjectContext() {
    try {
      const commits = await this.github.getCommitHistory('main', 5);
      return `Recent activity: ${commits.length} commits. Project uses JavaScript/Node.js.`;
    } catch {
      return 'JavaScript/Node.js project';
    }
  }

  async _getFileContent(file) {
    try {
      const content = await this.github.getRepositoryContent(file.filename || file.path);
      if (content?.content) {
        return Buffer.from(content.content, 'base64').toString();
      }
    } catch {
      return null;
    }
    return null;
  }
}

export default SDLCManager;