import { useMutation, useQuery, useQueryClient } from '@tanstack/react-query';
import { graphqlRequest } from '@/gql/graphql';
import { USERS_QUERY, CREATE_USER_MUTATION, UPDATE_USER_MUTATION, UPDATE_USER_STATUS_MUTATION } from '@/gql/users';
import { useTranslation } from 'react-i18next';
import { toast } from 'sonner';
import { useSelectedProjectId } from '@/stores/projectStore';
import { useErrorHandler } from '@/hooks/use-error-handler';
import { useRequestPermissions } from '@/hooks/useRequestPermissions';
import { User, UserConnection, ProjectUser, CreateUserInput, UpdateUserInput, userSchema, projectUserSchema } from './schema';

// Dynamic GraphQL query builder for project-level users
// This query fetches users with their project-specific information (owner status and scopes)
// Conditionally includes roles based on user permissions
function buildProjectUsersQuery(permissions: { canViewRoles: boolean }) {
  const rolesFields = permissions.canViewRoles
    ? `
            roles(where: { projectID: $projectId }) {
              edges {
                node {
                  id
                  name
                  level
                }
              }
            }`
    : '';

  return `
    query ProjectUsers($projectId: ID!) {
      node(id: $projectId) {
        ... on Project {
          id
          name
          projectUsers {
            id
            userID
            projectID
            isOwner
            scopes
            user {
              id
              createdAt
              updatedAt
              email
              status
              firstName
              lastName
              preferLanguage${rolesFields}
            }
          }
        }
      }
    }
  `;
}

// Mutation to add a user to a project
export const ADD_USER_TO_PROJECT_MUTATION = `
  mutation AddUserToProject($input: AddUserToProjectInput!) {
    addUserToProject(input: $input) {
      id
      userID
      projectID
      isOwner
      scopes
    }
  }
`;

// Mutation to remove a user from a project
export const REMOVE_USER_FROM_PROJECT_MUTATION = `
  mutation RemoveUserFromProject($input: RemoveUserFromProjectInput!) {
    removeUserFromProject(input: $input)
  }
`;

// Mutation to update user's project membership
export const UPDATE_PROJECT_USER_MUTATION = `
  mutation UpdateProjectUser($input: UpdateProjectUserInput!) {
    updateProjectUser(input: $input) {
      id
      userID
      projectID
      isOwner
      scopes
    }
  }
`;

// Query to get all users (for adding to project)
export const ALL_USERS_QUERY = `
  query AllUsers($first: Int, $after: Cursor, $where: UserWhereInput) {
    users(first: $first, after: $after, where: $where) {
      edges {
        node {
          id
          email
          firstName
          lastName
          status
        }
      }
      pageInfo {
        hasNextPage
        hasPreviousPage
        startCursor
        endCursor
      }
    }
  }
`;

// Query hooks - for project-level users
export function useUsers(
  variables?: {
    first?: number;
    after?: string;
    orderBy?: { field: 'CREATED_AT'; direction: 'ASC' | 'DESC' };
    where?: Record<string, any>;
  },
  options?: {
    disableAutoFetch?: boolean;
  }
) {
  const { t } = useTranslation();
  const { handleError } = useErrorHandler();
  const permissions = useRequestPermissions();
  const selectedProjectId = useSelectedProjectId();

  return useQuery({
    queryKey: ['project-users', selectedProjectId, variables, permissions],
    queryFn: async () => {
      try {
        if (!selectedProjectId) {
          throw new Error('No project selected');
        }

        const query = buildProjectUsersQuery(permissions);
        const headers = { 'X-Project-ID': selectedProjectId };
        const data = await graphqlRequest<{
          node: {
            id: string;
            name: string;
            projectUsers: ProjectUser[];
          };
        }>(query, { projectId: selectedProjectId }, headers);

        // Transform projectUsers to User format for display
        const projectUsers = data.node.projectUsers || [];
        const transformedUsers = projectUsers.map((pu) => {
          const parsedPU = projectUserSchema.parse(pu);
          return {
            id: parsedPU.user.id,
            createdAt: parsedPU.user.createdAt,
            updatedAt: parsedPU.user.updatedAt,
            email: parsedPU.user.email,
            status: parsedPU.user.status,
            firstName: parsedPU.user.firstName,
            lastName: parsedPU.user.lastName,
            preferLanguage: parsedPU.user.preferLanguage,
            isOwner: parsedPU.isOwner,
            scopes: parsedPU.scopes,
            roles: parsedPU.user.roles,
            projectUserId: parsedPU.id, // Store the project_user ID for removal
          };
        });

        // Sort by createdAt DESC (newest first)
        transformedUsers.sort((a, b) => new Date(b.createdAt).getTime() - new Date(a.createdAt).getTime());

        // Return in UserConnection format for compatibility
        return {
          edges: transformedUsers.map((user) => ({ node: user })),
          pageInfo: {
            hasNextPage: false,
            hasPreviousPage: false,
            startCursor: null,
            endCursor: null,
          },
        };
      } catch (error) {
        handleError(error, t('users.messages.loadUsersError'));
        throw error;
      }
    },
    enabled: !options?.disableAutoFetch && !!selectedProjectId,
  });
}

export function useUser(id: string) {
  const { t } = useTranslation();
  const { handleError } = useErrorHandler();
  const selectedProjectId = useSelectedProjectId();

  return useQuery({
    queryKey: ['user', id, selectedProjectId],
    queryFn: async () => {
      try {
        const headers = selectedProjectId ? { 'X-Project-ID': selectedProjectId } : undefined;
        const data = await graphqlRequest<{ users: UserConnection }>(USERS_QUERY, { where: { id } }, headers);
        const user = data.users.edges[0]?.node;
        if (!user) {
          throw new Error(t('users.messages.userNotFound'));
        }
        return userSchema.parse(user);
      } catch (error) {
        handleError(error, t('users.messages.loadUserError'));
        throw error;
      }
    },
    enabled: !!id,
  });
}

// Mutation hooks
export function useCreateUser() {
  const { t } = useTranslation();
  const queryClient = useQueryClient();
  const selectedProjectId = useSelectedProjectId();

  return useMutation({
    mutationFn: async (input: CreateUserInput) => {
      const headers = selectedProjectId ? { 'X-Project-ID': selectedProjectId } : undefined;
      const data = await graphqlRequest<{ createUser: User }>(CREATE_USER_MUTATION, { input }, headers);
      return userSchema.parse(data.createUser);
    },
    onSuccess: () => {
      queryClient.invalidateQueries({ queryKey: ['users'] });
      toast.success(t('users.messages.createSuccess'));
    },
    onError: (error: any) => {
      toast.error(t('users.messages.createError') + `: ${error.message}`);
    },
  });
}

export function useUpdateUser() {
  const { t } = useTranslation();
  const queryClient = useQueryClient();
  const selectedProjectId = useSelectedProjectId();

  return useMutation({
    mutationFn: async ({ id, input }: { id: string; input: UpdateUserInput }) => {
      const headers = selectedProjectId ? { 'X-Project-ID': selectedProjectId } : undefined;
      const data = await graphqlRequest<{ updateUser: User }>(UPDATE_USER_MUTATION, { id, input }, headers);
      return userSchema.parse(data.updateUser);
    },
    onSuccess: () => {
      queryClient.invalidateQueries({ queryKey: ['users'] });
      toast.success(t('users.messages.updateSuccess'));
    },
    onError: (error: any) => {
      toast.error(t('users.messages.updateError') + `: ${error.message}`);
    },
  });
}

export function useUpdateUserStatus() {
  const { t } = useTranslation();
  const queryClient = useQueryClient();
  const selectedProjectId = useSelectedProjectId();

  return useMutation({
    mutationFn: async ({ id, status }: { id: string; status: 'activated' | 'deactivated' }) => {
      const headers = selectedProjectId ? { 'X-Project-ID': selectedProjectId } : undefined;
      const data = await graphqlRequest<{ updateUserStatus: boolean }>(UPDATE_USER_STATUS_MUTATION, { id, status }, headers);
      return data.updateUserStatus;
    },
    onSuccess: (_data, variables) => {
      queryClient.invalidateQueries({ queryKey: ['users'] });
      queryClient.invalidateQueries({ queryKey: ['user', variables.id] });
      const statusText = variables.status === 'activated' ? t('users.status.activated') : t('users.status.deactivated');
      toast.success(t('users.messages.statusUpdateSuccess', { status: statusText }));
    },
    onError: (error: any) => {
      toast.error(t('users.messages.statusUpdateError') + `: ${error.message}`);
    },
  });
}

export function useDeleteUser() {
  const { t } = useTranslation();
  const queryClient = useQueryClient();

  return useMutation({
    mutationFn: async (_id: string) => {
      // This is now deprecated, use useRemoveUserFromProject instead
      throw new Error('Direct deletion is not supported. Use removeUserFromProject instead.');
    },
    onSuccess: () => {
      queryClient.invalidateQueries({ queryKey: ['users'] });
      toast.success(t('users.messages.deleteSuccess'));
    },
    onError: (error: any) => {
      toast.error(t('users.messages.deleteError') + `: ${error.message}`);
    },
  });
}

// Add user to project
export function useAddUserToProject() {
  const { t } = useTranslation();
  const queryClient = useQueryClient();
  const selectedProjectId = useSelectedProjectId();

  return useMutation({
    mutationFn: async (input: { userId: string; isOwner?: boolean; scopes?: string[]; roleIDs?: string[] }) => {
      if (!selectedProjectId) {
        throw new Error('No project selected');
      }
      const headers = { 'X-Project-ID': selectedProjectId };
      const data = await graphqlRequest<{ addUserToProject: any }>(
        ADD_USER_TO_PROJECT_MUTATION,
        {
          input: {
            projectId: selectedProjectId,
            userId: input.userId,
            isOwner: input.isOwner,
            scopes: input.scopes,
            roleIDs: input.roleIDs,
          },
        },
        headers
      );
      return data.addUserToProject;
    },
    onSuccess: () => {
      queryClient.invalidateQueries({ queryKey: ['project-users', selectedProjectId] });
      toast.success(t('users.messages.addToProjectSuccess'));
    },
    onError: (error: any) => {
      toast.error(t('users.messages.addToProjectError') + `: ${error.message}`);
    },
  });
}

// Remove user from project
export function useRemoveUserFromProject() {
  const { t } = useTranslation();
  const queryClient = useQueryClient();
  const selectedProjectId = useSelectedProjectId();

  return useMutation({
    mutationFn: async (userId: string) => {
      if (!selectedProjectId) {
        throw new Error('No project selected');
      }
      const headers = { 'X-Project-ID': selectedProjectId };
      const data = await graphqlRequest<{ removeUserFromProject: boolean }>(
        REMOVE_USER_FROM_PROJECT_MUTATION,
        {
          input: {
            projectId: selectedProjectId,
            userId: userId,
          },
        },
        headers
      );
      return data.removeUserFromProject;
    },
    onSuccess: () => {
      queryClient.invalidateQueries({ queryKey: ['project-users', selectedProjectId] });
      toast.success(t('users.messages.removeFromProjectSuccess'));
    },
    onError: (error: any) => {
      toast.error(t('users.messages.removeFromProjectError') + `: ${error.message}`);
    },
  });
}

// Update project user (for editing roles/scopes)
export function useUpdateProjectUser() {
  const { t } = useTranslation();
  const queryClient = useQueryClient();
  const selectedProjectId = useSelectedProjectId();

  return useMutation({
    mutationFn: async (input: {
      userId: string;
      isOwner?: boolean;
      scopes?: string[];
      addRoleIDs?: string[];
      removeRoleIDs?: string[];
    }) => {
      if (!selectedProjectId) {
        throw new Error('No project selected');
      }
      const headers = { 'X-Project-ID': selectedProjectId };
      const data = await graphqlRequest<{ updateProjectUser: any }>(
        UPDATE_PROJECT_USER_MUTATION,
        {
          input: {
            projectId: selectedProjectId,
            userId: input.userId,
            isOwner: input.isOwner,
            scopes: input.scopes,
            addRoleIDs: input.addRoleIDs,
            removeRoleIDs: input.removeRoleIDs,
          },
        },
        headers
      );
      return data.updateProjectUser;
    },
    onSuccess: () => {
      queryClient.invalidateQueries({ queryKey: ['project-users', selectedProjectId] });
      toast.success(t('users.messages.updateSuccess'));
    },
    onError: (error: any) => {
      toast.error(t('users.messages.updateError') + `: ${error.message}`);
    },
  });
}

// Get all users (for adding to project)
export function useAllUsers(variables?: { first?: number; after?: string; where?: Record<string, any> }, options?: { enabled?: boolean }) {
  const { t } = useTranslation();
  const { handleError } = useErrorHandler();

  return useQuery({
    queryKey: ['all-users', variables],
    queryFn: async () => {
      try {
        const data = await graphqlRequest<{ users: UserConnection }>(ALL_USERS_QUERY, variables);
        return data.users;
      } catch (error) {
        handleError(error, t('users.messages.loadUsersError'));
        throw error;
      }
    },
    enabled: options?.enabled ?? true,
  });
}

// Export users for compatibility
export const users = {
  useUsers,
  useUser,
  useCreateUser,
  useUpdateUser,
  useDeleteUser,
};