import type { Evaluation, DimensionScore, TemplateDimension, Template } from "@prisma/client";

export interface EvaluationWithScores extends Evaluation {
  template?: Template | null;
  dimensionScores: (DimensionScore & { dimension: TemplateDimension })[];
}

/** Compute average score across dimensions (1-5 scale) */
export function computeAverageScore(scores: { score: number | null }[]): number {
  const valid = scores.filter((s) => s.score != null && s.score >= 1 && s.score <= 5);
  if (valid.length === 0) return 0;
  return valid.reduce((a, s) => a + (s.score ?? 0), 0) / valid.length;
}

/** Generate findings paragraph from scores (deterministic template) */
export function generateFindings(
  scores: { score: number | null; dimension: { name?: string; title?: string } }[]
): string {
  const withScore = scores.filter((s) => s.score != null);
  if (withScore.length === 0) return "Aucun score enregistré pour l'instant.";

  const avg = computeAverageScore(withScore);
  const dimName = (d: { name?: string; title?: string }) => d.title ?? d.name ?? "";
  const weak = withScore.filter((s) => (s.score ?? 0) <= 2).map((s) => dimName(s.dimension));
  const strong = withScore.filter((s) => (s.score ?? 0) >= 4).map((s) => dimName(s.dimension));

  let text = `Score de maturité global : ${avg.toFixed(1)}/5. `;
  if (strong.length > 0) {
    text += `Points forts : ${strong.join(", ")}. `;
  }
  if (weak.length > 0) {
    text += `Axes d'amélioration : ${weak.join(", ")}.`;
  } else if (strong.length === 0) {
    text += "Les scores indiquent une maturité modérée sur les dimensions.";
  }
  return text;
}

/** Generate recommendations (deterministic template) */
export function generateRecommendations(
  scores: { score: number | null; dimension: { name?: string; title?: string } }[]
): string {
  const dimName = (d: { name?: string; title?: string }) => d.title ?? d.name ?? "";
  const weak = scores.filter((s) => (s.score ?? 5) <= 2).map((s) => dimName(s.dimension));
  if (weak.length === 0) return "Continuer à s'appuyer sur les pratiques actuelles. Envisager le mentorat pour les juniors.";
  return `Prioriser la formation et le développement pour : ${weak.join(", ")}. Envisager des programmes de montée en compétence structurés et une expertise externe si les écarts sont importants.`;
}

/** Convert evaluation to CSV rows (one per dimension + metadata row) */
export function evaluationToCsvRows(evalData: EvaluationWithScores): string[][] {
  const rows: string[][] = [];
  rows.push([
    "candidateName",
    "candidateRole",
    "evaluatorName",
    "evaluationDate",
    "template",
    "status",
    "dimension",
    "score",
    "justification",
    "examplesObserved",
    "confidence",
  ]);
  for (const ds of evalData.dimensionScores) {
    rows.push([
      evalData.candidateName,
      evalData.candidateRole,
      evalData.evaluatorName,
      evalData.evaluationDate.toISOString().split("T")[0],
      evalData.template?.name ?? "",
      evalData.status,
      (ds.dimension as { name?: string; title?: string }).title ?? (ds.dimension as { name?: string }).name ?? "",
      String(ds.score ?? ""),
      ds.justification ?? "",
      ds.examplesObserved ?? "",
      ds.confidence ?? "",
    ]);
  }
  return rows;
}