'use server';

import { getJiraAnalytics } from './jira-analytics';
import { formatDateForDisplay, getToday } from '@/lib/date-utils';

export type ExportFormat = 'csv' | 'json';

export type ExportResult = {
  success: boolean;
  data?: string;
  filename?: string;
  error?: string;
};

export interface JiraProjectMetrics {
  key: string;
  name: string;
  totalIssues: number;
}

export interface AssigneeMetrics {
  assignee: string;
  displayName: string;
  totalIssues: number;
  completedIssues: number;
  inProgressIssues: number;
  percentage: number;
}

export interface TeamMetrics {
  issuesDistribution: AssigneeMetrics[];
  totalAssignees: number;
  activeAssignees: number;
}

export interface SprintHistory {
  sprintName: string;
  startDate: string;
  endDate: string;
  plannedPoints: number;
  completedPoints: number;
  completionRate: number;
}

export interface VelocityMetrics {
  sprintHistory: SprintHistory[];
  currentSprintPoints: number;
  averageVelocity: number;
}

export interface CycleTimeByType {
  issueType: string;
  averageDays: number;
  medianDays: number;
  samples: number;
}

export interface CycleTimeMetrics {
  cycleTimeByType: CycleTimeByType[];
  averageCycleTime: number;
}

export interface WorkInProgressStatus {
  status: string;
  count: number;
  percentage: number;
}

export interface WorkInProgressAssignee {
  assignee: string;
  displayName: string;
  todoCount: number;
  inProgressCount: number;
  reviewCount: number;
  totalActive: number;
}

export interface WorkInProgress {
  byStatus: WorkInProgressStatus[];
  byAssignee: WorkInProgressAssignee[];
}

export interface JiraAnalytics {
  project: JiraProjectMetrics;
  teamMetrics: TeamMetrics;
  velocityMetrics: VelocityMetrics;
  cycleTimeMetrics: CycleTimeMetrics;
  workInProgress: WorkInProgress;
}

/**
 * Server Action pour exporter les analytics Jira au format CSV ou JSON
 */
export async function exportJiraAnalytics(format: ExportFormat = 'csv'): Promise<ExportResult> {
  try {
    // Récupérer les analytics (force refresh pour avoir les données les plus récentes)
    const analyticsResult = await getJiraAnalytics(true);
    
    if (!analyticsResult.success || !analyticsResult.data) {
      return {
        success: false,
        error: analyticsResult.error || 'Impossible de récupérer les analytics'
      };
    }

    const analytics = analyticsResult.data;
    const timestamp = new Date().toISOString().slice(0, 16).replace(/:/g, '-');
    const projectKey = analytics.project.key;

    if (format === 'json') {
      return {
        success: true,
        data: JSON.stringify(analytics, null, 2),
        filename: `jira-analytics-${projectKey}-${timestamp}.json`
      };
    }

    // Format CSV
    const csvData = generateCSV(analytics);
    
    return {
      success: true,
      data: csvData,
      filename: `jira-analytics-${projectKey}-${timestamp}.csv`
    };

  } catch (error) {
    console.error('❌ Erreur lors de l\'export des analytics:', error);
    
    return {
      success: false,
      error: error instanceof Error ? error.message : 'Erreur inconnue'
    };
  }
}

/**
 * Génère un CSV à partir des analytics Jira
 */
function generateCSV(analytics: JiraAnalytics): string {
  const lines: string[] = [];

  // Header du rapport
  lines.push('# Rapport Analytics Jira');
  lines.push(`# Projet: ${analytics.project.name} (${analytics.project.key})`);
  lines.push(`# Généré le: ${formatDateForDisplay(getToday(), 'DISPLAY_LONG')}`);
  lines.push(`# Total tickets: ${analytics.project.totalIssues}`);
  lines.push('');

  // Section 1: Métriques d'équipe
  lines.push('## Répartition de l\'équipe');
  lines.push('Assignee,Nom,Total Tickets,Tickets Complétés,Tickets En Cours,Pourcentage');
  analytics.teamMetrics.issuesDistribution.forEach((assignee: AssigneeMetrics) => {
    lines.push([
      escapeCsv(assignee.assignee),
      escapeCsv(assignee.displayName),
      assignee.totalIssues,
      assignee.completedIssues,
      assignee.inProgressIssues,
      assignee.percentage.toFixed(1) + '%'
    ].join(','));
  });
  lines.push('');

  // Section 2: Historique des sprints
  lines.push('## Historique des sprints');
  lines.push('Sprint,Date Début,Date Fin,Points Planifiés,Points Complétés,Taux de Complétion');
  analytics.velocityMetrics.sprintHistory.forEach((sprint: SprintHistory) => {
    lines.push([
      escapeCsv(sprint.sprintName),
      sprint.startDate.slice(0, 10),
      sprint.endDate.slice(0, 10),
      sprint.plannedPoints,
      sprint.completedPoints,
      sprint.completionRate + '%'
    ].join(','));
  });
  lines.push('');

  // Section 3: Cycle time par type
  lines.push('## Cycle Time par type de ticket');
  lines.push('Type de Ticket,Temps Moyen (jours),Temps Médian (jours),Échantillons');
  analytics.cycleTimeMetrics.cycleTimeByType.forEach((type: CycleTimeByType) => {
    lines.push([
      escapeCsv(type.issueType),
      type.averageDays,
      type.medianDays,
      type.samples
    ].join(','));
  });
  lines.push('');

  // Section 4: Work in Progress
  lines.push('## Work in Progress par statut');
  lines.push('Statut,Nombre,Pourcentage');
  analytics.workInProgress.byStatus.forEach((status: WorkInProgressStatus) => {
    lines.push([
      escapeCsv(status.status),
      status.count,
      status.percentage + '%'
    ].join(','));
  });
  lines.push('');

  // Section 5: Charge de travail par assignee
  lines.push('## Charge de travail par assignee');
  lines.push('Assignee,Nom,À Faire,En Cours,En Revue,Total Actif');
  analytics.workInProgress.byAssignee.forEach((assignee: WorkInProgressAssignee) => {
    lines.push([
      escapeCsv(assignee.assignee),
      escapeCsv(assignee.displayName),
      assignee.todoCount,
      assignee.inProgressCount,
      assignee.reviewCount,
      assignee.totalActive
    ].join(','));
  });
  lines.push('');

  // Section 6: Métriques résumé
  lines.push('## Métriques de résumé');
  lines.push('Métrique,Valeur');
  lines.push([
    'Total membres équipe',
    analytics.teamMetrics.totalAssignees
  ].join(','));
  lines.push([
    'Membres actifs',
    analytics.teamMetrics.activeAssignees
  ].join(','));
  lines.push([
    'Points complétés sprint actuel',
    analytics.velocityMetrics.currentSprintPoints
  ].join(','));
  lines.push([
    'Vélocité moyenne',
    analytics.velocityMetrics.averageVelocity
  ].join(','));
  lines.push([
    'Cycle time moyen (jours)',
    analytics.cycleTimeMetrics.averageCycleTime
  ].join(','));

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

/**
 * Échappe les valeurs CSV (guillemets, virgules, retours à la ligne)
 */
function escapeCsv(value: string): string {
  if (typeof value !== 'string') return String(value);
  
  // Si la valeur contient des guillemets, virgules ou retours à la ligne
  if (value.includes('"') || value.includes(',') || value.includes('\n')) {
    // Doubler les guillemets et entourer de guillemets
    return '"' + value.replace(/"/g, '""') + '"';
  }
  
  return value;
}