contrat nad booking modification

apps/edr-freight-api/src/modules/contracts/contract-document-diff.util.ts

@@ -0,0 +1,168 @@
+import type {
+  ContractDocumentArticle,
+  ContractDocumentSnapshot,
+} from './entities/contract.entity';
+
+/**
+ * One recorded change between two document snapshots. Granularity is per
+ * article: a body edit is reported as "the body changed", not as a text diff.
+ */
+export type ContractDocumentChange =
+  | { kind: 'ARTICLE_ADDED'; articleId: string; title: string }
+  | { kind: 'ARTICLE_REMOVED'; articleId: string; title: string }
+  | {
+      kind: 'ARTICLE_RENAMED';
+      articleId: string;
+      title: string;
+      fromTitle: string;
+    }
+  | { kind: 'ARTICLE_BODY_CHANGED'; articleId: string; title: string }
+  | {
+      kind: 'ARTICLE_REORDERED';
+      articleId: string;
+      title: string;
+      fromOrder: number;
+      toOrder: number;
+    }
+  | { kind: 'DOCUMENT_TITLE_CHANGED'; title: string; fromTitle: string | null }
+  | { kind: 'WHEREAS_CHANGED'; added: number; removed: number };
+
+type SnapshotLike = Pick<
+  ContractDocumentSnapshot,
+  'documentTitle' | 'whereasClauses' | 'articles'
+> | null;
+
+/** Match on id when present, else on normalized title (editors may omit ids). */
+function articleKey(article: ContractDocumentArticle): string {
+  return article.id || `title:${article.title.trim().toLowerCase()}`;
+}
+
+function indexArticles(
+  articles: ContractDocumentArticle[] | undefined,
+): Map<string, ContractDocumentArticle> {
+  const map = new Map<string, ContractDocumentArticle>();
+  for (const article of articles ?? []) {
+    map.set(articleKey(article), article);
+  }
+  return map;
+}
+
+/**
+ * Compare two document snapshots and describe what changed, article by article.
+ * Returns an empty array when the snapshots are equivalent, so callers can skip
+ * recording a no-op revision.
+ */
+export function diffSnapshots(
+  before: SnapshotLike,
+  after: SnapshotLike,
+): ContractDocumentChange[] {
+  const changes: ContractDocumentChange[] = [];
+
+  const beforeTitle = before?.documentTitle ?? null;
+  const afterTitle = after?.documentTitle ?? null;
+  if (beforeTitle !== afterTitle && afterTitle !== null) {
+    changes.push({
+      kind: 'DOCUMENT_TITLE_CHANGED',
+      title: afterTitle,
+      fromTitle: beforeTitle,
+    });
+  }
+
+  const beforeWhereas = before?.whereasClauses ?? [];
+  const afterWhereas = after?.whereasClauses ?? [];
+  const beforeWhereasSet = new Set(beforeWhereas);
+  const afterWhereasSet = new Set(afterWhereas);
+  const whereasAdded = afterWhereas.filter((c) => !beforeWhereasSet.has(c)).length;
+  const whereasRemoved = beforeWhereas.filter((c) => !afterWhereasSet.has(c)).length;
+  if (whereasAdded > 0 || whereasRemoved > 0) {
+    changes.push({
+      kind: 'WHEREAS_CHANGED',
+      added: whereasAdded,
+      removed: whereasRemoved,
+    });
+  }
+
+  const beforeArticles = indexArticles(before?.articles);
+  const afterArticles = indexArticles(after?.articles);
+
+  for (const [key, article] of afterArticles) {
+    const previous = beforeArticles.get(key);
+    if (!previous) {
+      changes.push({
+        kind: 'ARTICLE_ADDED',
+        articleId: article.id,
+        title: article.title,
+      });
+      continue;
+    }
+
+    if (previous.title !== article.title) {
+      changes.push({
+        kind: 'ARTICLE_RENAMED',
+        articleId: article.id,
+        title: article.title,
+        fromTitle: previous.title,
+      });
+    }
+    if (previous.body !== article.body) {
+      changes.push({
+        kind: 'ARTICLE_BODY_CHANGED',
+        articleId: article.id,
+        title: article.title,
+      });
+    }
+    if (previous.order !== article.order) {
+      changes.push({
+        kind: 'ARTICLE_REORDERED',
+        articleId: article.id,
+        title: article.title,
+        fromOrder: previous.order,
+        toOrder: article.order,
+      });
+    }
+  }
+
+  for (const [key, article] of beforeArticles) {
+    if (afterArticles.has(key)) continue;
+    changes.push({
+      kind: 'ARTICLE_REMOVED',
+      articleId: article.id,
+      title: article.title,
+    });
+  }
+
+  return changes;
+}
+
+/** Short human summary of a change set, e.g. "2 articles edited, 1 article added". */
+export function summarizeChanges(changes: ContractDocumentChange[]): string {
+  if (changes.length === 0) return 'No changes';
+
+  const articleVerbs: Record<string, string> = {
+    ARTICLE_ADDED: 'added',
+    ARTICLE_REMOVED: 'removed',
+    ARTICLE_RENAMED: 'renamed',
+    ARTICLE_BODY_CHANGED: 'edited',
+    ARTICLE_REORDERED: 'reordered',
+  };
+
+  const counts = new Map<string, number>();
+  const parts: string[] = [];
+
+  for (const change of changes) {
+    const verb = articleVerbs[change.kind];
+    if (verb) {
+      counts.set(verb, (counts.get(verb) ?? 0) + 1);
+    } else if (change.kind === 'DOCUMENT_TITLE_CHANGED') {
+      parts.push('document title changed');
+    } else if (change.kind === 'WHEREAS_CHANGED') {
+      parts.push('recitals changed');
+    }
+  }
+
+  const articleParts = [...counts.entries()].map(
+    ([verb, count]) => `${count} article${count === 1 ? '' : 's'} ${verb}`,
+  );
+
+  return [...articleParts, ...parts].join(', ');
+}