// ScoredRun — output of the deterministic Success Scorer (Phase 3).
// Spec mandates 4 categories with explicit reasons; we add scorer
// versioning so a future scorer change is detectable in historical data.
import {
  ValidationResult, requireString, requireIsoTimestamp, requireProvenance, requireStringArray, requireNumber,
} from "./types";

export const SCORED_RUN_SCHEMA_VERSION = 1;
export const SCORE_CATEGORIES = ["accepted", "partially_accepted", "rejected", "needs_human_review"] as const;
export type ScoreCategory = (typeof SCORE_CATEGORIES)[number];

export interface ScoredRun {
  schema_version: number;
  evidence_run_id: string;     // FK to EvidenceRecord.run_id
  evidence_task_id: string;    // FK to EvidenceRecord.task_id
  category: ScoreCategory;
  reasons: string[];           // human-readable, e.g. ["cargo_green=true", "anchor_grounding<0.7"]
  scored_at: string;           // ISO 8601
  scorer_version: string;      // e.g. "v1.0.0" — bumped on scorer code change
  // Sub-scores that the scorer collapsed into the category. Persisted
  // so a downstream UI can show "why" without re-running the scorer.
  sub_scores?: {
    cargo_green?: boolean;
    anchor_grounding?: number;
    schema_valid?: boolean;
    pathway_replay_succeeded?: boolean;
    observer_verdict?: "accept" | "reject" | "cycle";
    [key: string]: unknown;
  };
  provenance: {
    source_file: string;
    line_offset?: number;
    sig_hash: string;
    recorded_at: string;
  };
}

export function validateScoredRun(input: unknown): ValidationResult<ScoredRun> {
  const errors: string[] = [];
  if (typeof input !== "object" || input === null) {
    return { valid: false, errors: ["expected object"] };
  }
  const r = input as Record<string, unknown>;
  let ok = true;
  if (r.schema_version !== SCORED_RUN_SCHEMA_VERSION) {
    errors.push(`schema_version: expected ${SCORED_RUN_SCHEMA_VERSION}, got ${JSON.stringify(r.schema_version)}`);
    ok = false;
  }
  ok = requireString(r.evidence_run_id, "evidence_run_id", errors) && ok;
  ok = requireString(r.evidence_task_id, "evidence_task_id", errors) && ok;
  ok = requireIsoTimestamp(r.scored_at, "scored_at", errors) && ok;
  ok = requireString(r.scorer_version, "scorer_version", errors) && ok;
  ok = requireStringArray(r.reasons, "reasons", errors) && ok;
  if (Array.isArray(r.reasons) && r.reasons.length === 0) {
    errors.push("reasons: must be non-empty (every score must have at least one reason)");
    ok = false;
  }
  if (!SCORE_CATEGORIES.includes(r.category as ScoreCategory)) {
    errors.push(`category: must be one of ${SCORE_CATEGORIES.join("|")}, got ${JSON.stringify(r.category)}`);
    ok = false;
  }
  ok = requireProvenance(r.provenance, "provenance", errors) && ok;

  if (r.sub_scores !== undefined) {
    if (typeof r.sub_scores !== "object" || r.sub_scores === null) {
      errors.push("sub_scores: expected object when present");
      ok = false;
    } else {
      const ss = r.sub_scores as Record<string, unknown>;
      if (ss.anchor_grounding !== undefined) {
        if (!requireNumber(ss.anchor_grounding, "sub_scores.anchor_grounding", errors)) ok = false;
        else if ((ss.anchor_grounding as number) < 0 || (ss.anchor_grounding as number) > 1) {
          errors.push("sub_scores.anchor_grounding: must be in [0, 1]");
          ok = false;
        }
      }
      if (ss.observer_verdict !== undefined && !["accept", "reject", "cycle"].includes(ss.observer_verdict as string)) {
        errors.push("sub_scores.observer_verdict: must be accept|reject|cycle");
        ok = false;
      }
    }
  }

  if (!ok) return { valid: false, errors };
  return { valid: true, value: r as unknown as ScoredRun };
}