import { Player, Organization, Project } from '../types';

const API_URL = 'https://vollidioten.ceraticsoft.de/api';

class DatabaseService {
  private players: Player[] = [];
  private orgs: Organization[] = [];
  private projects: Project[] = [];
  private listeners: Function[] = [];

  constructor() {
    this.fetchAll();
  }

  // Fetch data from backend - always try to load fresh data
  async fetchAll() {
    try {
        console.log("Fetching data from API...");
        const [pRes, oRes, prRes] = await Promise.all([
            fetch(`${API_URL}/players`),
            fetch(`${API_URL}/orgs`),
            fetch(`${API_URL}/projects`)
        ]);

        if (pRes.ok && oRes.ok && prRes.ok) {
            const playersData = await pRes.json();
            const orgsData = await oRes.json();
            const projectsData = await prRes.json();

            console.log(`Loaded ${playersData.length} players, ${orgsData.length} orgs, ${projectsData.length} projects from API`);

            this.players = playersData;
            this.orgs = orgsData;
            this.projects = projectsData;
            this.notify();

            console.log("✅ Connected to Backend Database - using real data");
        } else {
            console.warn(`API returned errors: players=${pRes.status}, orgs=${oRes.status}, projects=${prRes.status}`);
            throw new Error("Backend unavailable");
        }
    } catch (e) {
        console.warn("Backend not available, data not loaded.", e);
        throw e; // Re-throw so components can handle the error
    }
  }

  subscribe(cb: Function) {
      this.listeners.push(cb);
      return () => {
          this.listeners = this.listeners.filter(l => l !== cb);
      };
  }

  notify() {
      this.listeners.forEach(cb => cb());
  }

  // --- READ ---

  getPlayers(): Player[] { return this.players; }
  getOrgs(): Organization[] { return this.orgs; }
  getProjects(): Project[] { return this.projects; }

  getPlayer(uuid: string): Player | undefined {
    return this.players.find(p => p.uuid === uuid);
  }

  // Fetch individual player data directly from API (for profile pages)
  async fetchPlayer(uuid: string): Promise<Player | null> {
    try {
      const response = await fetch(`${API_URL}/players/${uuid}`);
      if (response.ok) {
        const playerData = await response.json();
        // Update local cache
        this.players = this.players.map(p => p.uuid === uuid ? playerData : p);
        if (!this.players.find(p => p.uuid === uuid)) {
          this.players.push(playerData);
        }
        this.notify();
        return playerData;
      }
    } catch (e) {
      console.warn("Failed to fetch individual player data", e);
    }
    return null;
  }

  getOrg(id: string): Organization | undefined {
    return this.orgs.find(o => o.id === id);
  }

  getProject(id: string): Project | undefined {
    return this.projects.find(p => p.id === id);
  }

  // --- WRITE (Optimistic UI + API Call) ---

  async updatePlayer(uuid: string, updates: Partial<Player>) {
    // 1. Optimistic Update
    this.players = this.players.map(p => p.uuid === uuid ? { ...p, ...updates } : p);
    this.notify();

    // 2. API Call
    try {
        await fetch(`${API_URL}/players/${uuid}`, {
            method: 'PUT',
            headers: { 'Content-Type': 'application/json' },
            body: JSON.stringify(updates),
            credentials: 'include' // Sends session cookie
        });
    } catch (e) {
        console.error("Failed to save player update", e);
    }
  }

  async updateProject(id: string, updates: Partial<Project>) {
    this.projects = this.projects.map(p => p.id === id ? { ...p, ...updates } : p);
    this.notify();

    try {
        await fetch(`${API_URL}/projects/${id}`, {
            method: 'PUT',
            headers: { 'Content-Type': 'application/json' },
            body: JSON.stringify(updates),
            credentials: 'include'
        });
    } catch (e) {
        console.error("Failed to save project update", e);
    }
  }

  // --- PROJECT MANAGEMENT ---
  async createProject(projectData: { title: string; description: string; category: Project['category'] }): Promise<boolean> {
    try {
      const response = await fetch(`${API_URL}/projects`, {
        method: 'POST',
        headers: { 'Content-Type': 'application/json' },
        credentials: 'include',
        body: JSON.stringify(projectData),
      });

      if (response.ok) {
        // Reload data to include the new project
        await this.fetchAll();
        return true;
      }
      return false;
    } catch (e) {
      console.error("Failed to create project", e);
      return false;
    }
  }

  // --- LINKING ---
  async linkPlayer(playerUuid: string): Promise<boolean> {
     try {
        const res = await fetch(`${API_URL}/link-user`, {
            method: 'POST',
            headers: { 'Content-Type': 'application/json' },
            body: JSON.stringify({ playerUuid }),
            credentials: 'include'
        });
        if (res.ok) {
            // Reload data to reflect linking (might unlock edit buttons)
            await this.fetchAll();
            return true;
        }
        return false;
     } catch(e) {
        console.error("Link failed", e);
        return false;
     }
  }
}

export const dbService = new DatabaseService();