import { Injectable } from '@nestjs/common';
import { DataSource } from 'typeorm';

export interface DashboardAuditItem {
  id: string;
  occurredAt: Date;
  actorUsername: string | null;
  action: string;
  entityType: string | null;
  entityId: string | null;
}

interface DashboardCountsRow {
  totalAssets: number | string;
  assetsNeedValidation: number | string;
  assetsWithoutGeometry: number | string;
  plannedInspections: number | string;
  activeUsers: number | string;
  inactiveUsers: number | string;
  activeSessions: number | string;
  openFindings: number | string;
  awaitingCompanyResponse: number | string;
  overdueCompanyResponses: number | string;
  companyResponsesDueNext7Days: number | string;
  awaitingVerificationSchedule: number | string;
  overdueControls: number | string;
  controlsNext30Days: number | string;
}

export interface DashboardUpcomingControl {
  id: string;
  code: string;
  title: string;
  nextControlOn: string;
  actId: string;
  actCode: string;
  visitId: string;
  visitCode: string;
  assetId: string;
  assetCode: string;
  assetName: string;
}

@Injectable()
export class DashboardService {
  constructor(private readonly dataSource: DataSource) {}

  async summary() {
    return this.dataSource.transaction('REPEATABLE READ', async (manager) => {
      const [counts] = (await manager.query(`
        SELECT
          (SELECT COUNT(*) FROM assets WHERE information_status <> 'INACTIVE') AS "totalAssets",
          (SELECT COUNT(*) FROM assets WHERE information_status NOT IN ('VALIDATED','INACTIVE')) AS "assetsNeedValidation",
          (SELECT COUNT(*) FROM assets asset WHERE asset.information_status <> 'INACTIVE' AND NOT EXISTS (SELECT 1 FROM asset_geometries geometry WHERE geometry.asset_id=asset.id)) AS "assetsWithoutGeometry",
          (SELECT COUNT(*) FROM inspection_visits WHERE status='PLANNED') AS "plannedInspections",
          (SELECT COUNT(*) FROM users WHERE status = 'ACTIVE') AS "activeUsers",
          (SELECT COUNT(*) FROM users WHERE status = 'INACTIVE') AS "inactiveUsers",
          (
            SELECT COUNT(*)
            FROM auth_sessions
            WHERE revoked_at IS NULL
              AND expires_at > CURRENT_TIMESTAMP
          ) AS "activeSessions",
          (
            SELECT COUNT(*) FROM inspection_findings WHERE status = 'OPEN'
          ) AS "openFindings",
          (
            SELECT COUNT(*) FROM inspection_findings
            WHERE status = 'OPEN' AND company_response_received_on IS NULL
          ) AS "awaitingCompanyResponse",
          (
            SELECT COUNT(*) FROM inspection_findings
            WHERE status = 'OPEN'
              AND company_response_received_on IS NULL
              AND correction_due_on IS NOT NULL
              AND correction_due_on < (CURRENT_TIMESTAMP AT TIME ZONE 'America/Argentina/Mendoza')::date
          ) AS "overdueCompanyResponses",
          (
            SELECT COUNT(*) FROM inspection_findings
            WHERE status = 'OPEN'
              AND company_response_received_on IS NULL
              AND correction_due_on BETWEEN
                (CURRENT_TIMESTAMP AT TIME ZONE 'America/Argentina/Mendoza')::date
                AND (CURRENT_TIMESTAMP AT TIME ZONE 'America/Argentina/Mendoza')::date + 7
          ) AS "companyResponsesDueNext7Days",
          (
            SELECT COUNT(*) FROM inspection_findings
            WHERE status = 'OPEN'
              AND company_response_received_on IS NOT NULL
              AND next_control_on IS NULL
          ) AS "awaitingVerificationSchedule",
          (
            SELECT COUNT(*) FROM inspection_findings
            WHERE status = 'OPEN'
              AND company_response_received_on IS NOT NULL
              AND next_control_on < (CURRENT_TIMESTAMP AT TIME ZONE 'America/Argentina/Mendoza')::date
          ) AS "overdueControls",
          (
            SELECT COUNT(*) FROM inspection_findings
            WHERE status = 'OPEN'
              AND next_control_on BETWEEN
                (CURRENT_TIMESTAMP AT TIME ZONE 'America/Argentina/Mendoza')::date
                AND (CURRENT_TIMESTAMP AT TIME ZONE 'America/Argentina/Mendoza')::date + 30
          ) AS "controlsNext30Days"
      `)) as DashboardCountsRow[];

      const recentAudit = (await manager.query(`
        SELECT
          event.id,
          event.occurred_at AS "occurredAt",
          event.actor_username AS "actorUsername",
          event.action,
          event.entity_type AS "entityType",
          event.entity_id AS "entityId"
        FROM audit_events event
        ORDER BY event.occurred_at DESC, event.id DESC
        LIMIT 6
      `)) as DashboardAuditItem[];

      const upcomingControls = (await manager.query(`
        SELECT
          finding.id,
          finding.code,
          finding.title,
          finding.next_control_on AS "nextControlOn",
          act.id AS "actId",
          act.code AS "actCode",
          visit.id AS "visitId",
          visit.code AS "visitCode",
          asset.id AS "assetId",
          asset.code AS "assetCode",
          asset.name AS "assetName"
        FROM inspection_findings finding
        INNER JOIN inspection_acts act ON act.id = finding.act_id
        INNER JOIN inspection_visits visit ON visit.id = act.visit_id
        INNER JOIN assets asset ON asset.id = finding.asset_id
        WHERE finding.status = 'OPEN'
          AND finding.company_response_received_on IS NOT NULL
          AND finding.next_control_on IS NOT NULL
        ORDER BY finding.next_control_on, finding.code
        LIMIT 8
      `)) as DashboardUpcomingControl[];

      return {
        counts: {
          totalAssets: Number(counts?.totalAssets ?? 0),
          assetsNeedValidation: Number(counts?.assetsNeedValidation ?? 0),
          assetsWithoutGeometry: Number(counts?.assetsWithoutGeometry ?? 0),
          plannedInspections: Number(counts?.plannedInspections ?? 0),
          activeUsers: Number(counts?.activeUsers ?? 0),
          inactiveUsers: Number(counts?.inactiveUsers ?? 0),
          activeSessions: Number(counts?.activeSessions ?? 0),
          openFindings: Number(counts?.openFindings ?? 0),
          awaitingCompanyResponse: Number(counts?.awaitingCompanyResponse ?? 0),
          overdueCompanyResponses: Number(counts?.overdueCompanyResponses ?? 0),
          companyResponsesDueNext7Days: Number(counts?.companyResponsesDueNext7Days ?? 0),
          awaitingVerificationSchedule: Number(counts?.awaitingVerificationSchedule ?? 0),
          overdueControls: Number(counts?.overdueControls ?? 0),
          controlsNext30Days: Number(counts?.controlsNext30Days ?? 0),
        },
        recentAudit,
        upcomingControls,
        generatedAt: new Date().toISOString(),
      };
    });
  }
}