// ---------------------------------------------------------------------------
// Query History — automatisches Tracking aller ausgefuehrten Queries
// ---------------------------------------------------------------------------

export interface HistoryEntry {
  id: string;
  sql: string;
  executedAt: string;
  executionTimeMs?: number;
  rowCount?: number;
  isFavorite: boolean;
  name?: string;
}

const STORAGE_KEY = 'logfire-query-history';
const MAX_ENTRIES = 200;

export class HistoryManager {
  private entries = new Map<string, HistoryEntry>();
  private listeners = new Set<() => void>();

  constructor() {
    this.load();
  }

  // ---------------------------------------------------------------------------
  // Persistence
  // ---------------------------------------------------------------------------

  private load(): void {
    const raw = localStorage.getItem(STORAGE_KEY);
    if (!raw) return;
    try {
      const arr: HistoryEntry[] = JSON.parse(raw);
      for (const e of arr) this.entries.set(e.id, e);
    } catch { /* ignore */ }
  }

  private save(): void {
    localStorage.setItem(
      STORAGE_KEY,
      JSON.stringify(Array.from(this.entries.values())),
    );
    for (const fn of this.listeners) fn();
  }

  onChange(fn: () => void): () => void {
    this.listeners.add(fn);
    return () => this.listeners.delete(fn);
  }

  // ---------------------------------------------------------------------------
  // CRUD
  // ---------------------------------------------------------------------------

  addEntry(sql: string, executionTimeMs?: number, rowCount?: number): HistoryEntry {
    // Deduplizieren: gleiche SQL aktualisiert vorhandenen Eintrag
    for (const entry of this.entries.values()) {
      if (entry.sql === sql) {
        entry.executedAt = new Date().toISOString();
        entry.executionTimeMs = executionTimeMs;
        entry.rowCount = rowCount;
        this.save();
        return entry;
      }
    }

    const entry: HistoryEntry = {
      id: `h-${Date.now()}-${Math.random().toString(36).slice(2, 8)}`,
      sql,
      executedAt: new Date().toISOString(),
      executionTimeMs,
      rowCount,
      isFavorite: false,
    };
    this.entries.set(entry.id, entry);

    // Limit: aelteste nicht-favorisierte loeschen
    if (this.entries.size > MAX_ENTRIES) {
      const sorted = this.getAll();
      for (const e of sorted.slice(MAX_ENTRIES)) {
        if (!e.isFavorite) this.entries.delete(e.id);
      }
    }

    this.save();
    return entry;
  }

  getAll(searchTerm?: string): HistoryEntry[] {
    let results = Array.from(this.entries.values());

    if (searchTerm) {
      const term = searchTerm.toLowerCase();
      results = results.filter(
        e => e.sql.toLowerCase().includes(term) || e.name?.toLowerCase().includes(term),
      );
    }

    return results.sort(
      (a, b) => new Date(b.executedAt).getTime() - new Date(a.executedAt).getTime(),
    );
  }

  toggleFavorite(id: string): void {
    const e = this.entries.get(id);
    if (e) { e.isFavorite = !e.isFavorite; this.save(); }
  }

  setName(id: string, name: string): void {
    const e = this.entries.get(id);
    if (e) { e.name = name || undefined; this.save(); }
  }

  delete(id: string): void {
    this.entries.delete(id);
    this.save();
  }

  clear(): void {
    for (const [id, entry] of this.entries) {
      if (!entry.isFavorite) this.entries.delete(id);
    }
    this.save();
  }
}