import {
  BAT_COLOR_HEX,
  BAT_LEVEL_TO_SCORE,
  getColorClassFromScore,
  SCORE_TO_METRIC,
} from "@api/shared/constants/assessment-scores.constants";
import {
  ListObjectsV2Command,
  PutObjectCommand,
  S3Client,
} from "@aws-sdk/client-s3";
import { optionalEnv } from "@bish-nest/runtime-env";
import { BNestReportService } from "@bish-nest/admin/modules/report/report.service";
import { BNestPrismaService } from "@bish-nest/prisma";
import { BNestAngularSSRService } from "@bish-nest/reporting";
import { Inject, Injectable, Logger, NotFoundException } from "@nestjs/common";
import { ConfigService } from "@nestjs/config";
import { AssessmentType } from "@prisma/client";
import { BatChartService } from "./bat-chart.service";

/**
 * PreBatAnalysisService
 *
 * Integration API — Pre Bat Analysis. Business Logic Service for RecallAssess.
 */


@Injectable()
export class PreBatAnalysisService {
  private toNumber(value: unknown, fallback: number): number {
    const n = Number(value);
    return Number.isFinite(n) ? n : fallback;
  }
  private readonly logger = new Logger(PreBatAnalysisService.name);
  private readonly s3: S3Client | null;

  constructor(
    private readonly prisma: BNestPrismaService,
    private readonly config: ConfigService,
    @Inject() private readonly reportService: BNestReportService,
    @Inject() private readonly angularSSR: BNestAngularSSRService,
    private readonly batChartService: BatChartService,
  ) {
    // Initialize S3 client
    const awsRegion = this.config.get("AWS_REGION");
    const awsAccessKeyId = this.config.get("AWS_ACCESS_KEY_ID");
    const awsSecretAccessKey = this.config.get("AWS_SECRET_ACCESS_KEY");

    if (awsRegion) {
      this.s3 = new S3Client({
        region: awsRegion,
        ...(awsAccessKeyId && awsSecretAccessKey
          ? {
              credentials: {
                accessKeyId: awsAccessKeyId,
                secretAccessKey: awsSecretAccessKey,
              },
            }
          : {}),
      });
    } else {
      this.s3 = null;
      this.logger.warn("AWS_REGION not configured, S3 operations will be disabled");
    }
  }

  /**
   * Get Pre-BAT report data for the Angular report component
   * Extracts and formats data needed by pre-bat-analysis.component
   * @param learningGroupId Learning group ID
   * @param participantId Participant ID
   * @param course Course object
   * @param includeChartImage Whether to include chart image
   * @param freshAnalysisData Optional fresh analysis data
   * @returns Report data object for the Angular component
   */
  async getPreBatAnalysisData(
    learningGroupId: number,
    participantId: number,
    course: { id: number; assessment_id: number | null; title: string | null },
    includeChartImage = false,
    freshAnalysisData?: string,
  ): Promise<{
    courseTitle: string;
    participantName: string;
    skills: string; // JSON stringified array
    ipq: number;
    preTrainingResults: string; // JSON stringified array
    preReport: string;
    chartImage?: string | null;
  }> {
    // Verify learning group exists
    const learningGroup = await this.prisma.client.learningGroup.findUnique({
      where: { id: learningGroupId },
      select: { id: true },
    });

    if (!learningGroup) {
      throw new NotFoundException(`Learning group with ID ${learningGroupId} not found`);
    }

    // Verify participant exists
    const participant = await this.prisma.client.participant.findUnique({
      where: { id: participantId },
    });

    if (!participant) {
      throw new NotFoundException(`Participant with ID ${participantId} not found`);
    }

    // Verify course exists and has assessment
    const fullCourse = await this.prisma.client.course.findUnique({
      where: { id: course.id },
    });

    if (!fullCourse) {
      throw new NotFoundException(`Course not found for learning group ${learningGroupId}`);
    }

    if (!fullCourse.assessment_id) {
      throw new NotFoundException(`Course ${course.id} does not have an assessment assigned`);
    }

    // Get the stored analysis data for this learning group
    const assessmentParticipant = await this.prisma.client.assessmentParticipant.findFirst({
      where: {
        assessment_id: fullCourse.assessment_id,
        participant_id: participantId,
        learning_group_id: learningGroupId,
        assessment_type: AssessmentType.PRE_BAT,
      },
    });

    if (!assessmentParticipant) {
      throw new NotFoundException(
        `Pre-BAT assessment not found for participant ${participantId} in learning group ${learningGroupId}`,
      );
    }

    // Get actual assessment results from database
    let assessmentResults = await this.prisma.client.assessmentResult.findMany({
      where: {
        course_id: course.id,
        assessment_id: fullCourse.assessment_id,
        participant_id: participantId,
      },
      select: {
        id: true,
        assessment_question_id: true,
        grade_level: true,
        course_module_id: true,
        created_at: true,
        assessmentQuestion: {
          select: {
            id: true,
            sort_order: true,
            question_text: true,
            courseModule: {
              select: {
                id: true,
                title: true,
                course_module_code: true,
              },
            },
          },
        },
        courseModule: {
          select: {
            id: true,
            title: true,
            course_module_code: true,
          },
        },
        assessmentAnswer: {
          select: {
            answer_level: true,
          },
        },
      },
    });

    // Filter to PRE_BAT results only
    const postBatParticipant = await this.prisma.client.assessmentParticipant.findFirst({
      where: {
        assessment_id: fullCourse.assessment_id,
        participant_id: participantId,
        learning_group_id: learningGroupId,
        assessment_type: AssessmentType.POST_BAT,
      },
    });

    const preBatStartTime = new Date(assessmentParticipant.created_at.getTime() - 5000);

    if (postBatParticipant?.created_at) {
      assessmentResults = assessmentResults.filter(
        (r) => r.created_at >= preBatStartTime && r.created_at < postBatParticipant.created_at,
      );
    } else {
      const upperBound = assessmentParticipant.assessment_completion_date
        ? new Date(assessmentParticipant.assessment_completion_date.getTime() + 5000)
        : new Date(assessmentParticipant.created_at.getTime() + 60000);

      assessmentResults = assessmentResults.filter(
        (r) => r.created_at >= preBatStartTime && r.created_at <= upperBound,
      );
    }

    // Sort assessment results by question sort_order to ensure questions appear in the correct order in the report
    assessmentResults = assessmentResults.sort((a, b) => {
      const sortOrderA = this.toNumber(a.assessmentQuestion?.sort_order, 999999);
      const sortOrderB = this.toNumber(b.assessmentQuestion?.sort_order, 999999);
      if (sortOrderA === sortOrderB) {
        return (a.assessmentQuestion?.id ?? 0) - (b.assessmentQuestion?.id ?? 0);
      }
      return sortOrderA - sortOrderB;
    });

    // Get course modules to map skills
    const courseModulePages = await this.prisma.client.courseModulePage.findMany({
      where: {
        course_id: course.id,
        courseModule: {
          is_published: true,
          exclude_from_bat: false,
        },
      },
      select: {
        courseModule: {
          select: {
            id: true,
            course_module_code: true,
            title: true,
            sort_order: true,
          },
        },
      },
    });

    // Extract modules from course pages and sort
    const coursePageModules = courseModulePages
      .map((page) => page.courseModule)
      .filter((module): module is NonNullable<typeof module> => module !== null)
      .filter((module, index, self) => self.findIndex((m) => m.id === module.id) === index)
      .sort((a, b) => (a.sort_order || 0) - (b.sort_order || 0));

    // Get all modules that have assessment questions (for fallback)
    const allModuleIds = [
      ...new Set(assessmentResults.map((r) => r.course_module_id).filter((id) => id !== null)),
    ];
    const allModules = await this.prisma.client.courseModule.findMany({
      where: {
        id: { in: allModuleIds as number[] },
      },
      select: {
        id: true,
        title: true,
        course_module_code: true,
        sort_order: true,
      },
    });

    // Sort modules based on assessment question sort_order, not course module sort_order
    const moduleQuestionSortOrder = new Map<number, number>();

    assessmentResults.forEach((result) => {
      const moduleId =
        result.course_module_id || result.assessmentQuestion?.courseModule?.id || result.courseModule?.id;
      if (!moduleId) return;

      const questionSortOrder = this.toNumber(result.assessmentQuestion?.sort_order, 999999);
      const currentMin = moduleQuestionSortOrder.get(moduleId);

      if (currentMin === undefined || questionSortOrder < currentMin) {
        moduleQuestionSortOrder.set(moduleId, questionSortOrder);
      }
    });

    // Sort modules by the minimum question sort_order for each module
    const courseModules = allModules.sort((a, b) => {
      const sortOrderA = moduleQuestionSortOrder.get(a.id) ?? 999999;
      const sortOrderB = moduleQuestionSortOrder.get(b.id) ?? 999999;
      if (sortOrderA === sortOrderB) {
        const moduleSortA = a.sort_order ?? 999999;
        const moduleSortB = b.sort_order ?? 999999;
        if (moduleSortA === moduleSortB) {
          return a.id - b.id;
        }
        return moduleSortA - moduleSortB;
      }
      return sortOrderA - sortOrderB;
    });

    this.logger.log(`Pre-BAT PDF: Assessment results have modules: ${allModuleIds.join(", ")}`);
    this.logger.log(
      `Pre-BAT PDF: Found modules sorted by question sort_order: ${courseModules.map((m) => `${m.id}:${m.title} (min_q_sort: ${moduleQuestionSortOrder.get(m.id) ?? "N/A"})`).join(", ")}`,
    );

    // Parse the analysis data for pre_report text
    const analysisData = freshAnalysisData || assessmentParticipant.ai_analysis;
    let preReport = "";
    if (analysisData) {
      try {
        const parsedAnalysis = JSON.parse(analysisData) as {
          result?: { trainees?: Array<{ pre_report?: string }> };
          trainees?: Array<{ pre_report?: string }>;
          pre_report?: string;
        };
        preReport =
          parsedAnalysis?.result?.trainees?.[0]?.pre_report ||
          parsedAnalysis?.trainees?.[0]?.pre_report ||
          parsedAnalysis?.pre_report ||
          analysisData;
      } catch {
        preReport = analysisData;
      }
    }

    // Calculate skills from actual assessment results
    const skills = this.calculateSkillsFromResults(assessmentResults, courseModules);
    this.logger.log(`Pre-BAT PDF: Found ${courseModules.length} modules, generated ${skills.length} skills`);
    const ipq = assessmentParticipant.individual_quotient
      ? Number(assessmentParticipant.individual_quotient)
      : this.calculateIpqFromResults(assessmentResults);
    const preTrainingResults = this.calculatePreTrainingResults(skills);
    let chartImage: string | null | undefined;
    if (includeChartImage) {
      const chartStart = Date.now();
      this.logger.log("[PRE-BAT-PDF] chartImage START");
      try {
        chartImage = await this.batChartService.renderPreBatChart(skills, {
          centerColor: this.batChartService.getCenterColorHexFromIpq(ipq),
          centerLabel: ipq.toFixed(2),
        });
        this.logger.log(
          `[PRE-BAT-PDF] chartImage DONE duration=${Date.now() - chartStart}ms present=${chartImage ? "yes" : "no"} approxBytes=${chartImage ? chartImage.length : 0}`,
        );
      } catch (error) {
        // renderPreBatChart is documented fault-tolerant, but log loudly if it ever throws.
        const message = error instanceof Error ? error.message : String(error);
        this.logger.warn(
          `[PRE-BAT-PDF] chartImage FAILED (non-fatal, continuing) duration=${Date.now() - chartStart}ms error=${message}`,
        );
        chartImage = null;
      }
    }

    // Get participant name
    const participantName =
      participant.first_name && participant.last_name
        ? `${participant.first_name} ${participant.last_name}`
        : participant.email || `Participant ${participantId}`;

    return {
      courseTitle: fullCourse.title || fullCourse.course_code || `course-${course.id}`,
      participantName,
      skills: JSON.stringify(skills),
      ipq,
      preTrainingResults: JSON.stringify(preTrainingResults),
      preReport: preReport.replace(/\n/g, "<br>"),
      chartImage,
    };
  }

  /**
   * Calculate skills from actual assessment results
   */
  private calculateSkillsFromResults(
    assessmentResults: Array<{
      grade_level: string | null;
      course_module_id: number | null;
      assessmentQuestion?: {
        sort_order?: unknown | null;
        courseModule?: { id?: number | null; title: string | null; course_module_code: string | null } | null;
      } | null;
      courseModule?: { id?: number | null; title: string | null; course_module_code: string | null } | null;
      assessmentAnswer?: { answer_level?: string | null } | null;
    }>,
    courseModules: Array<{
      id: number;
      title: string;
      course_module_code: string | null;
      sort_order?: number | null;
    }>,
    allModulesMap?: Map<
      number,
      { id: number; title: string; course_module_code: string | null; sort_order?: number | null }
    >,
  ): Array<{ name: string; percentage: number; colorClass: string; score: number; sortOrder?: number | null }> {
    // Create a map of course modules for quick lookup by ID
    const courseModuleMap = new Map<
      number,
      { id: number; title: string; course_module_code: string | null; sort_order?: number | null }
    >();
    courseModules.forEach((module) => {
      courseModuleMap.set(module.id, module);
    });

    // Also include any additional modules from allModulesMap
    if (allModulesMap) {
      allModulesMap.forEach((module, id) => {
        if (!courseModuleMap.has(id)) {
          courseModuleMap.set(id, module);
        }
      });
    }

    // Calculate minimum question sort_order for each module
    const moduleQuestionSortOrder = new Map<number, number>();
    assessmentResults.forEach((result) => {
      const moduleId =
        result.course_module_id || result.assessmentQuestion?.courseModule?.id || result.courseModule?.id || null;
      if (!moduleId) return;

      const questionSortOrder = this.toNumber(result.assessmentQuestion?.sort_order, 999999);
      const currentMin = moduleQuestionSortOrder.get(moduleId);

      if (currentMin === undefined || questionSortOrder < currentMin) {
        moduleQuestionSortOrder.set(moduleId, questionSortOrder);
      }
    });

    // Initialize ALL course modules first
    const moduleScores = new Map<
      number,
      {
        name: string;
        scores: number[];
        totalScore: number;
        count: number;
        sortOrder?: number | null;
        moduleId: number;
      }
    >();

    courseModuleMap.forEach((moduleInfo, moduleId) => {
      const questionSortOrder = moduleQuestionSortOrder.get(moduleId);
      moduleScores.set(moduleId, {
        name: moduleInfo.title,
        scores: [],
        totalScore: 0,
        count: 0,
        sortOrder: questionSortOrder !== undefined ? questionSortOrder : moduleInfo.sort_order,
        moduleId: moduleId,
      });
    });

    // Process assessment results
    this.logger.log(`Processing ${assessmentResults.length} assessment results for pre-BAT report`);

    assessmentResults.forEach((result) => {
      const moduleId =
        result.course_module_id || result.assessmentQuestion?.courseModule?.id || result.courseModule?.id || null;

      if (!moduleId) {
        this.logger.warn(`No module ID found for assessment result. Result ID: ${(result as { id?: number }).id}`);
        return;
      }

      const moduleInfo = courseModuleMap.get(moduleId);
      if (!moduleInfo) {
        this.logger.warn(`Module ID ${moduleId} not found in course modules map`);
        return;
      }

      if (!moduleScores.has(moduleId)) {
        moduleScores.set(moduleId, {
          name: moduleInfo.title,
          scores: [],
          totalScore: 0,
          count: 0,
          sortOrder: moduleInfo.sort_order,
          moduleId: moduleId,
        });
      }

      const gradeLevel = (result.grade_level || result.assessmentAnswer?.answer_level || "INTERMEDIATE") as string;
      const score = BAT_LEVEL_TO_SCORE[gradeLevel as keyof typeof BAT_LEVEL_TO_SCORE] ?? 0;

      if (!result.grade_level && !result.assessmentAnswer?.answer_level) {
        this.logger.warn(
          `No grade_level found for assessment result ID ${(result as { id?: number }).id}, defaulting to INTERMEDIATE (score: ${score})`,
        );
      }

      const moduleData = moduleScores.get(moduleId);
      if (moduleData) {
        moduleData.scores.push(score);
        moduleData.totalScore += score;
        moduleData.count++;
      }
    });

    // Calculate average score per module and convert to skills format
    const skills: Array<{
      name: string;
      percentage: number;
      colorClass: string;
      score: number;
      sortOrder?: number | null;
    }> = [];

    courseModules.forEach((module) => {
      const moduleData = moduleScores.get(module.id);

      if (!moduleData) {
        this.logger.warn(`Module ${module.id} (${module.title}) not found in moduleScores`);
        return;
      }

      // For modules without assessment results, show 0% with gray color
      if (moduleData.count === 0) {
        const questionSortOrder = moduleQuestionSortOrder.get(module.id);
        skills.push({
          name: moduleData.name,
          percentage: 0,
          colorClass: "gray",
          score: 0,
          sortOrder:
            questionSortOrder !== undefined ? questionSortOrder : (module.sort_order ?? moduleData.sortOrder),
        });
        return;
      }

      const averageScore = moduleData.totalScore / moduleData.count;
      const mappedScore = Math.round(averageScore);
      const metric = SCORE_TO_METRIC[mappedScore];

      const percentage = metric?.percentage ?? Math.max(0, Math.min(100, ((averageScore + 2) / 4) * 100));

      const colorClass = metric?.colorClass ?? getColorClassFromScore(averageScore);

      const questionSortOrder = moduleQuestionSortOrder.get(module.id);

      skills.push({
        name: moduleData.name,
        percentage: Math.round(percentage),
        colorClass,
        score: Number(averageScore.toFixed(2)),
        sortOrder:
          questionSortOrder !== undefined ? questionSortOrder : (module.sort_order ?? moduleData.sortOrder),
      });
    });

    // Sort by sort_order (ascending)
    skills.sort((a, b) => {
      const aSort = a.sortOrder ?? 999999;
      const bSort = b.sortOrder ?? 999999;
      return aSort - bSort;
    });

    return skills;
  }

  /**
   * Calculate IPQ (Individual Performance Quotient) from assessment results
   */
  private calculateIpqFromResults(
    assessmentResults: Array<{
      grade_level: string | null;
      assessmentAnswer?: { answer_level?: string | null } | null;
    }>,
  ): number {
    if (assessmentResults.length === 0) return 0;

    let totalScore = 0;
    let count = 0;

    assessmentResults.forEach((result) => {
      const gradeLevel = (result.grade_level || result.assessmentAnswer?.answer_level || "INTERMEDIATE") as string;
      const score = BAT_LEVEL_TO_SCORE[gradeLevel as keyof typeof BAT_LEVEL_TO_SCORE] ?? -1;
      totalScore += score;
      count++;
    });

    return count > 0 ? Number((totalScore / count).toFixed(2)) : 0;
  }

  /**
   * Calculate pre-training results distribution
   */
  private calculatePreTrainingResults(
    skills: Array<{ score: number; colorClass: string; percentage: number }>,
  ): Array<{
    color: string;
    colorClass: string;
    count: number;
    total: number;
    percentage: number;
  }> {
    const total = skills.length;

    let foundation = 0;
    let belowAverage = 0;
    let good = 0;
    let excellent = 0;

    skills.forEach((skill) => {
      switch (skill.colorClass) {
        case "red":
          foundation++;
          break;
        case "orange":
          belowAverage++;
          break;
        case "light-green":
        case "green":
          good++;
          break;
        case "gray":
          // Modules without answers are also "gray" (0%); only answered Average modules count here.
          if (skill.percentage > 0) good++;
          break;
        case "dark-green":
          excellent++;
          break;
      }
    });

    const createEntry = (color: string, colorClass: string, count: number) => ({
      color,
      colorClass,
      count,
      total,
      percentage: total > 0 ? Number.parseFloat(((count / total) * 100).toFixed(2)) : 0,
    });

    return [
      createEntry(BAT_COLOR_HEX.red, "red", foundation),
      createEntry(BAT_COLOR_HEX.orange, "orange", belowAverage),
      createEntry(BAT_COLOR_HEX["light-green"], "light-green", good),
      createEntry(BAT_COLOR_HEX["dark-green"], "dark-green", excellent),
    ];
  }

  /**
   * Generate Pre-BAT HTML preview
   */
  async generatePreBatHtml(learningGroupId: number, participantId: number): Promise<string> {
    this.logger.log(
      `Generating pre-BAT HTML preview for participant ${participantId} in learning group ${learningGroupId}`,
    );

    const learningGroup = await this.prisma.client.learningGroup.findUnique({
      where: { id: learningGroupId },
      select: { course: true },
    });

    if (!learningGroup) {
      throw new NotFoundException(`Learning group with ID ${learningGroupId} not found`);
    }

    const course = learningGroup.course;
    if (!course) {
      throw new NotFoundException(`Course not found for learning group ${learningGroupId}`);
    }

    const reportDataRaw = await this.getPreBatAnalysisData(
      learningGroupId,
      participantId,
      {
        id: course.id,
        assessment_id: course.assessment_id,
        title: course.title,
      },
      true,
    );

    const skillsParsed = JSON.parse(reportDataRaw.skills);
    const preTrainingResultsParsed = JSON.parse(reportDataRaw.preTrainingResults);

    const reportData = {
      courseTitle: reportDataRaw.courseTitle,
      participantName: reportDataRaw.participantName,
      skills: skillsParsed,
      ipq: reportDataRaw.ipq,
      preTrainingResults: preTrainingResultsParsed,
      preReport: reportDataRaw.preReport,
      chartImage: reportDataRaw.chartImage,
    };

    const serverDistPath = optionalEnv(
      "ANGULAR_SERVER_DIST_PATH",
      "dist/apps/recallassess/recallassess-admin-pwa/server",
    );
    const reportRoute = `/report/preview/paged/pre-bat-analysis`;
    const html = await this.angularSSR.renderReport(serverDistPath, reportRoute, reportData);

    return html;
  }

  /**
   * Generate Pre-BAT PDF directly and return buffer
   */
  async generatePreBatPdfDirect(
    learningGroupId: number,
    participantId: number,
    course: { id: number; assessment_id: number | null; title: string | null },
  ): Promise<Buffer> {
    const reportDataRaw = await this.getPreBatAnalysisData(learningGroupId, participantId, course, true);

    const skillsParsed = JSON.parse(reportDataRaw.skills);
    const preTrainingResultsParsed = JSON.parse(reportDataRaw.preTrainingResults);

    const reportData = {
      courseTitle: reportDataRaw.courseTitle,
      participantName: reportDataRaw.participantName,
      skills: skillsParsed,
      ipq: reportDataRaw.ipq,
      preTrainingResults: preTrainingResultsParsed,
      preReport: reportDataRaw.preReport,
      chartImage: reportDataRaw.chartImage,
    };

    const pdfBuffer = await this.reportService.generateReportPdf("pre-bat-analysis", "paged", reportData);

    return pdfBuffer;
  }

  /**
   * Ensure Pre-BAT PDF exists in S3 (always regenerates to pick up latest report template).
   */
  /**
   * Resolve the Pre-BAT PDF S3 path for a participant.
   *
   * @param forceRegenerate When `false` (default), an existing PDF in S3 is reused —
   *   this is the fast path for downloads. When `true`, the PDF is always rebuilt
   *   and re-uploaded (used by the admin "Regenerate" action).
   */
  async checkPreBatPdfExists(
    learningGroupId: number,
    participantId: number,
    forceRegenerate = false,
  ): Promise<string> {
    const t0 = Date.now();
    const prefix = `private/report-log/${learningGroupId}/document/${participantId}-pre-bat`;
    const bucketName = this.config.get("AWS_S3_MEDIA_BUCKET");

    this.logger.log(
      `[PRE-BAT-PDF][step 2] checkPreBatPdfExists START lg=${learningGroupId} participant=${participantId} forceRegenerate=${forceRegenerate} prefix=${prefix}`,
    );

    if (!bucketName) {
      throw new Error("AWS_S3_MEDIA_BUCKET environment variable is required");
    }

    if (!this.s3) {
      throw new NotFoundException(
        `Pre-BAT PDF not found for participant ${participantId} in learning group ${learningGroupId}. Report generation failed. Please contact the administrator.`,
      );
    }

    try {
      const s3ListStart = Date.now();
      const result = await this.s3.send(
        new ListObjectsV2Command({
          Bucket: bucketName,
          Prefix: prefix,
        }),
      );
      this.logger.log(
        `[PRE-BAT-PDF][step 3] S3 ListObjectsV2 done in ${Date.now() - s3ListStart}ms — matches=${result.Contents?.length ?? 0}`,
      );

      if (result.Contents && result.Contents.length > 0) {
        const sortedContents = result.Contents.sort(
          (a, b) => (b.LastModified?.getTime() || 0) - (a.LastModified?.getTime() || 0),
        );
        const mostRecentPdf = sortedContents[0];
        if (mostRecentPdf.Key) {
          if (!forceRegenerate) {
            this.logger.log(
              `[PRE-BAT-PDF][step 4] CACHE HIT — reusing S3 key=${mostRecentPdf.Key} (total ${Date.now() - t0}ms). NO render needed.`,
            );
            return mostRecentPdf.Key;
          }
          this.logger.log(
            `[PRE-BAT-PDF][step 4] S3 key=${mostRecentPdf.Key} found but forceRegenerate=true; rebuilding.`,
          );
        }
      } else {
        this.logger.log(
          `[PRE-BAT-PDF][step 4] CACHE MISS — no PDF in S3 for participant ${participantId} lg ${learningGroupId}. Falling into SLOW synchronous render path.`,
        );
      }
    } catch (error: unknown) {
      const errorMessage = error instanceof Error ? error.message : String(error);
      this.logger.error(`[PRE-BAT-PDF][step 4] S3 ListObjectsV2 FAILED after ${Date.now() - t0}ms: ${errorMessage}`);
      throw new NotFoundException(
        `Pre-BAT PDF not found for participant ${participantId} in learning group ${learningGroupId}. Error: ${errorMessage}`,
      );
    }

    const course = await this.resolveCourseForPreBatPdf(learningGroupId);
    this.logger.log(`[PRE-BAT-PDF][step 5] Resolved course id=${course.id}; starting synchronous render.`);
    return this.generateAndUploadPreBatPdf(learningGroupId, participantId, course);
  }

  private async resolveCourseForPreBatPdf(learningGroupId: number): Promise<{
    id: number;
    assessment_id: number | null;
    title: string | null;
  }> {
    const learningGroup = await this.prisma.client.learningGroup.findUnique({
      where: { id: learningGroupId },
      select: {
        id: true,
        course: {
          select: {
            id: true,
            assessment_id: true,
            title: true,
          },
        },
      },
    });

    if (!learningGroup || !learningGroup.course) {
      throw new NotFoundException(
        `Learning group ${learningGroupId} or its course could not be found while generating Pre-BAT PDF.`,
      );
    }

    const course = learningGroup.course;

    if (!course.assessment_id) {
      throw new NotFoundException(`Course ${course.id} does not have an assessment assigned`);
    }

    return {
      id: course.id,
      assessment_id: course.assessment_id,
      title: course.title,
    };
  }

  /**
   * Generate PDF and upload to S3
   */
  async generateAndUploadPreBatPdf(
    learningGroupId: number,
    participantId: number,
    course: { id: number; assessment_id: number | null; title: string | null },
    authorization?: string,
    freshAnalysisData?: string,
  ): Promise<string> {
    const t0 = Date.now();
    const cid = `pretbat[lg=${learningGroupId} p=${participantId}]`;
    this.logger.log(`[PRE-BAT-PDF][${cid}] START`);
    this.logger.log(
      `[PRE-BAT-PDF][${cid}] generateAndUploadPreBatPdf START course=${course.id}`,
    );

    let reportDataRaw: Awaited<ReturnType<PreBatAnalysisService["getPreBatAnalysisData"]>>;
    const dataStart = Date.now();
    try {
      reportDataRaw = await this.getPreBatAnalysisData(
        learningGroupId,
        participantId,
        course,
        true,
        freshAnalysisData,
      );
      this.logger.log(
        `[PRE-BAT-PDF][${cid}] getPreBatAnalysisData DONE duration=${Date.now() - dataStart}ms`,
      );
    } catch (error) {
      const message = error instanceof Error ? error.message : String(error);
      const stack = error instanceof Error ? error.stack : undefined;
      this.logger.error(
        `[PRE-BAT-PDF][${cid}] FAILED\n  stage=getPreBatAnalysisData\n  duration=${Date.now() - dataStart}ms\n  error=${message}\n  stack=${stack ?? "n/a"}`,
      );
      throw error;
    }

    const skillsParsed = JSON.parse(reportDataRaw.skills);
    const preTrainingResultsParsed = JSON.parse(reportDataRaw.preTrainingResults);

    const reportData = {
      courseTitle: reportDataRaw.courseTitle,
      participantName: reportDataRaw.participantName,
      skills: skillsParsed,
      ipq: reportDataRaw.ipq,
      preTrainingResults: preTrainingResultsParsed,
      preReport: reportDataRaw.preReport,
      chartImage: reportDataRaw.chartImage,
    };

    const renderStart = Date.now();
    this.logger.log(
      `[PRE-BAT-PDF][${cid}] reportService.generateReportPdf START (SSR + Paged.js — expected slowest stage)`,
    );
    let pdfBuffer: Buffer;
    try {
      pdfBuffer = await this.reportService.generateReportPdf(
        "pre-bat-analysis",
        "paged",
        reportData,
        authorization,
      );
      this.logger.log(
        `[PRE-BAT-PDF][${cid}] PDF BUFFER CREATED duration=${Date.now() - renderStart}ms size=${pdfBuffer.length} bytes`,
      );
    } catch (error) {
      const message = error instanceof Error ? error.message : String(error);
      const stack = error instanceof Error ? error.stack : undefined;
      this.logger.error(
        `[PRE-BAT-PDF][${cid}] FAILED\n  stage=generateReportPdf(SSR+PagedJS)\n  duration=${Date.now() - renderStart}ms\n  error=${message}\n  stack=${stack ?? "n/a"}`,
      );
      throw error;
    }

    const s3Path = `private/report-log/${learningGroupId}/document/${participantId}-pre-bat.pdf`;
    const bucketName = this.config.get("AWS_S3_MEDIA_BUCKET");

    if (!bucketName) {
      throw new Error("AWS_S3_MEDIA_BUCKET environment variable is required");
    }

    if (!this.s3) {
      this.logger.warn(`⚠ S3 disabled - Skipping upload for: ${s3Path}`);
      return s3Path;
    }

    const uploadStart = Date.now();
    this.logger.log(`[PRE-BAT-PDF][${cid}] S3 UPLOAD START key=${s3Path}`);
    try {
      await this.s3.send(
        new PutObjectCommand({
          Bucket: bucketName,
          Key: s3Path,
          Body: pdfBuffer,
          ContentType: "application/pdf",
          ContentDisposition: "attachment",
        }),
      );
      this.logger.log(
        `[PRE-BAT-PDF][${cid}] S3 UPLOAD DONE duration=${Date.now() - uploadStart}ms key=${s3Path}`,
      );
    } catch (error) {
      const message = error instanceof Error ? error.message : String(error);
      const stack = error instanceof Error ? error.stack : undefined;
      this.logger.error(
        `[PRE-BAT-PDF][${cid}] FAILED\n  stage=S3.PutObject\n  duration=${Date.now() - uploadStart}ms\n  error=${message}\n  stack=${stack ?? "n/a"}`,
      );
      throw error;
    }

    this.logger.log(`[PRE-BAT-PDF][${cid}] COMPLETED totalDuration=${Date.now() - t0}ms`);
    return s3Path;
  }
}