import { createStore } from 'zustand/vanilla';
import { useSyncExternalStore } from 'react';

export interface PersonaOption {
  id: string;
  label: string;
  description: string;
  colors: { torso: string; legs: string };
  modelPath?: string;
}

export interface PersonaState {
  personas: PersonaOption[];
  isHydrated: boolean;
}

export interface PersonaActions {
  addPersona: (persona: Omit<PersonaOption, 'id'> & { id?: string }) => void;
  removePersona: (id: string) => void;
  updatePersona: (id: string, updates: Partial<Omit<PersonaOption, 'id'>>) => void;
  resetPersonas: () => void;
  hydrate: () => void;
}

export type PersonaStore = PersonaState & PersonaActions;

export const DEFAULT_PERSONAS: PersonaOption[] = [
  {
    id: 'none',
    label: 'Default',
    description: 'Original robot appearance',
    colors: { torso: '#3b82f6', legs: '#3b82f6' },
  },
  {
    id: 'emarati-kandura',
    label: 'Emarati Kandura',
    description: 'Traditional white robe attire',
    colors: { torso: '#f8fafc', legs: '#f8fafc' },
  },
  {
    id: 'industrial-vest',
    label: 'Industrial Vest',
    description: 'High-visibility safety vest',
    colors: { torso: '#f59e0b', legs: '#3b82f6' },
  },
  {
    id: 'business-suit',
    label: 'Business Suit',
    description: 'Professional navy suit',
    colors: { torso: '#1e293b', legs: '#1e293b' },
  },
];

const STORAGE_KEY = 'lootah-personas';

function loadFromStorage(): PersonaOption[] | null {
  if (typeof window === 'undefined') return null;
  try {
    const raw = localStorage.getItem(STORAGE_KEY);
    if (!raw) return null;
    const parsed = JSON.parse(raw);
    if (!Array.isArray(parsed)) return null;
    return parsed;
  } catch {
    return null;
  }
}

function saveToStorage(personas: PersonaOption[]) {
  if (typeof window === 'undefined') return;
  try {
    localStorage.setItem(STORAGE_KEY, JSON.stringify(personas));
  } catch {
    // Storage unavailable
  }
}

function generateId(): string {
  return `persona-${Date.now()}-${Math.random().toString(36).slice(2, 7)}`;
}

export const personaStore = createStore<PersonaStore>((set, get) => ({
  personas: DEFAULT_PERSONAS,
  isHydrated: false,

  addPersona: (persona) => {
    const newPersona: PersonaOption = {
      id: persona.id ?? generateId(),
      label: persona.label,
      description: persona.description,
      colors: persona.colors,
      ...(persona.modelPath ? { modelPath: persona.modelPath } : {}),
    };
    set((state) => {
      const updated = [...state.personas, newPersona];
      saveToStorage(updated);
      return { personas: updated };
    });
  },

  removePersona: (id) => {
    // Prevent removing the default 'none' persona
    if (id === 'none') return;
    set((state) => {
      const updated = state.personas.filter((p) => p.id !== id);
      saveToStorage(updated);
      return { personas: updated };
    });
  },

  updatePersona: (id, updates) => {
    set((state) => {
      const updated = state.personas.map((p) =>
        p.id === id ? { ...p, ...updates } : p
      );
      saveToStorage(updated);
      return { personas: updated };
    });
  },

  resetPersonas: () => {
    saveToStorage(DEFAULT_PERSONAS);
    set({ personas: [...DEFAULT_PERSONAS] });
  },

  hydrate: () => {
    const stored = loadFromStorage();
    if (stored && stored.length > 0) {
      // Only re-inject truly built-in personas (those still in DEFAULT_PERSONAS) if missing.
      // Dynamic/uploaded personas that were deleted via the dashboard must NOT be re-added.
      const storedIds = new Set(stored.map((s) => s.id));
      const missing = DEFAULT_PERSONAS.filter((d) => !storedIds.has(d.id));
      set({ personas: [...stored, ...missing], isHydrated: true });
    } else {
      set({ personas: [...DEFAULT_PERSONAS], isHydrated: true });
    }

    // Fetch pricing items from server DB and auto-register personas for all attire items
    if (typeof window !== 'undefined') {
      fetch('/api/admin/pricing/')
        .then((r) => r.json())
        .then((data) => {
          const serverItems: { id: string; label: string; modelPath: string | null }[] = data.items ?? [];
          const current = get().personas;
          const currentIds = new Set(current.map((p) => p.id));
          const newPersonas: PersonaOption[] = [];
          // Items that should not appear as selectable personas
          const excludeIds = new Set(['base', 'custom-color']);

          serverItems.forEach(({ id, label, modelPath }) => {
            if (excludeIds.has(id)) return;
            if (currentIds.has(id)) {
              // Update modelPath if it changed
              const existing = current.find((p) => p.id === id);
              if (existing && modelPath && existing.modelPath !== modelPath) {
                set((state) => ({
                  personas: state.personas.map((p) =>
                    p.id === id ? { ...p, modelPath } : p
                  ),
                }));
              }
            } else {
              // Auto-create a persona entry for every pricing item
              newPersonas.push({
                id,
                label,
                description: label,
                colors: { torso: '#3b82f6', legs: '#3b82f6' },
                ...(modelPath ? { modelPath } : {}),
              });
            }
          });

          if (newPersonas.length > 0) {
            set((state) => {
              const updated = [...state.personas, ...newPersonas];
              saveToStorage(updated);
              return { personas: updated };
            });
          } else {
            // Save current state to localStorage so it persists
            saveToStorage(get().personas);
          }
        })
        .catch(() => {}); // silent — use local data as fallback
    }
  },
}));

export const usePersonaStore = <T>(selector: (state: PersonaStore) => T): T => {
  return useSyncExternalStore(
    personaStore.subscribe,
    () => selector(personaStore.getState()),
    () => selector(personaStore.getState())
  );
};