import { create } from 'zustand';
import { useEditorStore } from './editorStore';
import { useAuthStore } from './authStore';

export interface Collaborator {
  userId: string;
  username: string;
  permission: 'view' | 'edit' | 'admin';
  activeFileId: string | null;
  cursor: { line: number; ch: number } | null;
  selectedBlockId: string | null;
  selectedElementId: string | null;
  joinedAt: number;
}

export interface RemotePointer {
  x: number;
  y: number;
  username: string;
}

export interface RemoteBlockDrag {
  blockId: string;
  x: number;
  y: number;
}

interface CollaboratorOwner {
  id: string;
  username: string;
}

interface CollaborationStore {
  connected: boolean;
  collaborators: Collaborator[];
  owner: CollaboratorOwner | null;
  lastSaved: number | null;
  savedBy: string | null;
  remotePointers: Record<string, RemotePointer>;
  remoteBlockDrags: Record<string, RemoteBlockDrag>;
  pendingBlockConnects: Array<{ childId: string; parentId: string; inputName?: string }>;
  pendingBlockChanges: Array<{ blockId: string; name: string; value: any }>;
  pendingBlockCreates: Array<{ blockId: string; xml: string }>;
  setConnected: (connected: boolean) => void;
  setCollaborators: (collaborators: Collaborator[]) => void;
  setOwner: (owner: CollaboratorOwner) => void;
  addCollaborator: (collaborator: Collaborator) => void;
  removeCollaborator: (userId: string) => void;
  updateActiveFile: (userId: string, fileId: string | null) => void;
  updateCursor: (userId: string, fileId: string, cursor: { line: number; ch: number } | null) => void;
  updateBlockSelection: (userId: string, blockId: string | null) => void;
  updateElementHover: (userId: string, elementId: string | null) => void;
  updateFile: (fileId: string, content: string) => void;
  setLastSaved: (timestamp: number) => void;
  setSavedBy: (username: string) => void;
  setRemotePointer: (userId: string, pointer: RemotePointer) => void;
  clearRemotePointer: (userId: string) => void;
  setRemoteBlockDrag: (userId: string, drag: RemoteBlockDrag) => void;
  updateRemoteBlockDrag: (userId: string, updates: { x: number; y: number }) => void;
  clearRemoteBlockDrag: (userId: string) => void;
  pushPendingBlockConnect: (data: { childId: string; parentId: string; inputName?: string }) => void;
  shiftPendingBlockConnect: () => { childId: string; parentId: string; inputName?: string } | undefined;
  pushPendingBlockChange: (data: { blockId: string; name: string; value: any }) => void;
  shiftPendingBlockChange: () => { blockId: string; name: string; value: any } | undefined;
  pushPendingBlockCreate: (data: { blockId: string; xml: string }) => void;
  shiftPendingBlockCreate: () => { blockId: string; xml: string } | undefined;
  getCollaboratorsOnFile: (fileId: string) => Collaborator[];
  getCollaboratorsOnBlock: (blockId: string) => Collaborator[];
  getCollaboratorsOnElement: (elementId: string) => Collaborator[];
  isViewOnly: () => boolean;
}

export const useCollaborationStore = create<CollaborationStore>((set, get) => ({
  connected: false,
  collaborators: [],
  owner: null,
  lastSaved: null,
  savedBy: null,
  remotePointers: {},
  remoteBlockDrags: {},
  pendingBlockConnects: [],
  pendingBlockChanges: [],
  pendingBlockCreates: [],

  setConnected: (connected) => set({ connected }),

  setCollaborators: (collaborators) => {
    // Deduplicate by userId, keeping the most recent entry per user
    const deduped = Array.from(
      new Map(collaborators.map((c) => [c.userId, c])).values()
    );
    set({ collaborators: deduped });
  },

  setOwner: (owner) => set({ owner }),

  addCollaborator: (collaborator) =>
    set((state) => {
      const exists = state.collaborators.find((c) => c.userId === collaborator.userId);
      if (exists) return state;
      return { collaborators: [...state.collaborators, collaborator] };
    }),

  removeCollaborator: (userId) =>
    set((state) => {
      const { [userId]: _p, ...restPointers } = state.remotePointers;
      const { [userId]: _d, ...restDrags } = state.remoteBlockDrags;
      return {
        collaborators: state.collaborators.filter((c) => c.userId !== userId),
        remotePointers: restPointers,
        remoteBlockDrags: restDrags,
      };
    }),

  updateActiveFile: (userId, fileId) =>
    set((state) => ({
      collaborators: state.collaborators.map((c) =>
        c.userId === userId ? { ...c, activeFileId: fileId } : c
      ),
    })),

  updateCursor: (userId, fileId, cursor) =>
    set((state) => ({
      collaborators: state.collaborators.map((c) =>
        c.userId === userId ? { ...c, cursor, activeFileId: fileId } : c
      ),
    })),

  updateBlockSelection: (userId, blockId) =>
    set((state) => ({
      collaborators: state.collaborators.map((c) =>
        c.userId === userId ? { ...c, selectedBlockId: blockId } : c
      ),
    })),

  updateElementHover: (userId, elementId) =>
    set((state) => ({
      collaborators: state.collaborators.map((c) =>
        c.userId === userId ? { ...c, selectedElementId: elementId } : c
      ),
    })),

  updateFile: (fileId, content) => {
    const state = useEditorStore.getState();
    if (state.activeFileId === fileId) {
      state.setActiveFileContent(content);
    }
    state.updateFile(fileId, { content });
  },

  setLastSaved: (timestamp) => set({ lastSaved: timestamp }),

  setSavedBy: (username) => set({ savedBy: username }),

  getCollaboratorsOnFile: (fileId) => {
    return get().collaborators.filter((c) => c.activeFileId === fileId);
  },

  getCollaboratorsOnBlock: (blockId) => {
    return get().collaborators.filter((c) => c.selectedBlockId === blockId);
  },

  getCollaboratorsOnElement: (elementId) => {
    return get().collaborators.filter((c) => c.selectedElementId === elementId);
  },

  isViewOnly: () => {
    const user = useAuthStore.getState().user;
    const collab = get().collaborators.find((c) => c.userId === user?.id);
    return collab?.permission === 'view';
  },

  setRemotePointer: (userId, pointer) =>
    set((state) => ({
      remotePointers: { ...state.remotePointers, [userId]: pointer },
    })),

  clearRemotePointer: (userId) =>
    set((state) => {
      const { [userId]: _, ...rest } = state.remotePointers;
      return { remotePointers: rest };
    }),

  setRemoteBlockDrag: (userId, drag) =>
    set((state) => ({
      remoteBlockDrags: { ...state.remoteBlockDrags, [userId]: drag },
    })),

  updateRemoteBlockDrag: (userId, updates) =>
    set((state) => {
      const existing = state.remoteBlockDrags[userId];
      if (!existing) return state;
      return {
        remoteBlockDrags: {
          ...state.remoteBlockDrags,
          [userId]: { ...existing, ...updates },
        },
      };
    }),

  clearRemoteBlockDrag: (userId) =>
    set((state) => {
      const { [userId]: _, ...rest } = state.remoteBlockDrags;
      return { remoteBlockDrags: rest };
    }),

  pushPendingBlockConnect: (data) =>
    set((state) => ({
      pendingBlockConnects: [...state.pendingBlockConnects, data],
    })),
  shiftPendingBlockConnect: () => {
    const state = get();
    const [first, ...rest] = state.pendingBlockConnects;
    if (first) {
      set({ pendingBlockConnects: rest });
    }
    return first;
  },

  pushPendingBlockChange: (data) =>
    set((state) => ({
      pendingBlockChanges: [...state.pendingBlockChanges, data],
    })),
  shiftPendingBlockChange: () => {
    const state = get();
    const [first, ...rest] = state.pendingBlockChanges;
    if (first) {
      set({ pendingBlockChanges: rest });
    }
    return first;
  },

  pushPendingBlockCreate: (data) =>
    set((state) => ({
      pendingBlockCreates: [...state.pendingBlockCreates, data],
    })),
  shiftPendingBlockCreate: () => {
    const state = get();
    const [first, ...rest] = state.pendingBlockCreates;
    if (first) {
      set({ pendingBlockCreates: rest });
    }
    return first;
  },
}));