/**
 * cli:derive-seed-delta — validate.ts
 *
 * Two-stage validation:
 *  1. Structural (Zod) — schema parse, dotted-numeric version.
 *  2. Business — resolvedRenames coherence (navigation entries need a level,
 *     from ≠ to, no double-claim of the same source key).
 */
import { DeriveSeedDeltaSpecSchema, type DeriveSeedDeltaSpec, type ValidationResult } from './types.js';

export function validateStructure(raw: unknown): ValidationResult {
  const result = DeriveSeedDeltaSpecSchema.safeParse(raw);
  if (result.success) return { valid: true, errors: [], warnings: [] };
  const errors = result.error.issues.map((i) => `[${i.path.join('.')}] ${i.message}`);
  return { valid: false, errors, warnings: [] };
}

export function validateBusinessRules(spec: DeriveSeedDeltaSpec): ValidationResult {
  const errors: string[] = [];
  const warnings: string[] = [];

  const claimed = new Set<string>();
  for (const r of spec.resolvedRenames) {
    const ctx = `resolvedRenames[${r.kind}:${r.from}->${r.to}]`;
    if (r.kind === 'navigation' && !r.level) {
      errors.push(`${ctx}: navigation renames require 'level' (application|module|section|resource).`);
    }
    if (r.from === r.to) {
      errors.push(`${ctx}: 'from' and 'to' are identical — not a rename.`);
    }
    const key = `${r.app}|${r.kind}|${r.level ?? ''}|${r.parentCode ?? ''}|${r.from}`;
    if (claimed.has(key)) {
      errors.push(`${ctx}: source '${r.from}' is claimed by more than one resolution in the same scope.`);
    }
    claimed.add(key);
  }

  return { valid: errors.length === 0, errors, warnings };
}

export function validate(raw: unknown): ValidationResult {
  const structural = validateStructure(raw);
  if (!structural.valid) return structural;
  const spec = DeriveSeedDeltaSpecSchema.parse(raw);
  return validateBusinessRules(spec);
}