import { keepPreviousData, useInfiniteQuery, useMutation, useQuery, useQueryClient } from "@tanstack/react-query";

import { api } from "./client";
import type { components } from "./schema";

export class HttpError extends Error {
  constructor(public readonly status: number) {
    super(`HTTP ${status}`);
    this.name = "HttpError";
  }
}

type UserView = components["schemas"]["UserView"];
type LoginRequest = components["schemas"]["LoginRequest"];

export function useMe() {
  return useQuery({
    queryKey: ["me"],
    queryFn: async (): Promise<UserView | null> => {
      const { data, response } = await api.GET("/api/admin/me");

      if (response.status === 401) return null;

      if (!data) throw new Error("failed to load session");

      return data;
    },
    retry: false,
  });
}

export function useObjectsPage(limit: number, offset: number) {
  return useQuery({
    queryKey: ["objects", { limit, offset }],
    queryFn: async () => {
      const { data, error } = await api.GET("/api/admin/objects", {
        params: { query: { limit, offset } },
      });

      if (error || !data) throw new Error("failed to load objects");

      return data;
    },
  });
}

export function useObject(id: string) {
  return useQuery({
    queryKey: ["object", id],
    queryFn: async () => {
      const { data, response } = await api.GET("/api/admin/objects/{id}", {
        params: { path: { id } },
      });

      if (response.status === 404) return null;

      if (!data) throw new Error("failed to load object");

      return data;
    },
    // A 404 resolves to null rather than erroring, so don't retry it.
    retry: false,
  });
}

export function useFieldDefinitions() {
  return useQuery({
    queryKey: ["field-definitions"],
    queryFn: async () => {
      const { data, error } = await api.GET("/api/admin/field-definitions");

      if (error || !data) throw new Error("failed to load field definitions");

      return data;
    },
    staleTime: 5 * 60 * 1000,
  });
}

export function useLogin() {
  const qc = useQueryClient();

  return useMutation({
    mutationFn: async (body: LoginRequest) => {
      const { response } = await api.POST("/api/admin/login", { body });

      if (response.status !== 204) {
        throw new Error(response.status === 401 ? "invalid" : "network");
      }
    },
    onSuccess: () => qc.invalidateQueries({ queryKey: ["me"] }),
  });
}

export function useLogout() {
  const qc = useQueryClient();

  return useMutation({
    mutationFn: async () => {
      await api.POST("/api/admin/logout");
    },
    onSuccess: () => qc.setQueryData(["me"], null),
  });
}

type ObjectCreateRequest = components["schemas"]["ObjectCreateRequest"];
type ObjectUpdateRequest = components["schemas"]["ObjectUpdateRequest"];

export function useTerms(vocabularyId: string | null | undefined) {
  return useQuery({
    queryKey: ["terms", vocabularyId],
    enabled: !!vocabularyId,
    queryFn: async () => {
      const { data, error } = await api.GET("/api/admin/vocabularies/{id}/terms", {
        params: { path: { id: vocabularyId! } },
      });

      if (error || !data) throw new Error("failed to load terms");

      return data;
    },
    staleTime: 5 * 60 * 1000,
  });
}

export function useAuthorities(kind: string | null | undefined) {
  return useQuery({
    queryKey: ["authorities", kind],
    enabled: !!kind,
    queryFn: async () => {
      const { data, error } = await api.GET("/api/admin/authorities", {
        params: { query: { kind: kind! } },
      });

      if (error || !data) throw new Error("failed to load authorities");

      return data;
    },
    staleTime: 5 * 60 * 1000,
  });
}

export function useCreateObject() {
  const qc = useQueryClient();

  return useMutation({
    mutationFn: async (body: ObjectCreateRequest) => {
      const { data, error } = await api.POST("/api/admin/objects", { body });

      if (error || !data) throw new Error("create failed");

      return data;
    },
    onSuccess: () => qc.invalidateQueries({ queryKey: ["objects"] }),
  });
}

export function useUpdateObject() {
  const qc = useQueryClient();

  return useMutation({
    mutationFn: async ({ id, body }: { id: string; body: ObjectUpdateRequest }) => {
      const { response } = await api.PUT("/api/admin/objects/{id}", {
        params: { path: { id } },
        body,
      });

      if (response.status !== 204) throw new Error("update failed");
    },
    onSuccess: (_d, { id }) => {
      void qc.invalidateQueries({ queryKey: ["objects"] });
      void qc.invalidateQueries({ queryKey: ["object", id] });
    },
  });
}

export function useSetFields() {
  const qc = useQueryClient();

  return useMutation({
    mutationFn: async ({ id, fields }: { id: string; fields: Record<string, unknown> }) => {
      const { response } = await api.PUT("/api/admin/objects/{id}/fields", {
        params: { path: { id } },
        body: fields as Record<string, never>,
      });

      if (response.status !== 204) throw new Error("set fields failed");
    },
    onSuccess: (_d, { id }) => {
      void qc.invalidateQueries({ queryKey: ["object", id] });
    },
  });
}

export function useDeleteObject() {
  const qc = useQueryClient();

  return useMutation({
    mutationFn: async (id: string) => {
      const { response } = await api.DELETE("/api/admin/objects/{id}", {
        params: { path: { id } },
      });

      if (response.status !== 204) throw new Error("delete failed");
    },
    onSuccess: () => qc.invalidateQueries({ queryKey: ["objects"] }),
  });
}

type NewVocabularyRequest = components["schemas"]["NewVocabularyRequest"];
type LabelInput = components["schemas"]["LabelInput"];

export function useVocabularies() {
  return useQuery({
    queryKey: ["vocabularies"],
    queryFn: async () => {
      const { data, error } = await api.GET("/api/admin/vocabularies");

      if (error || !data) throw new Error("failed to load vocabularies");

      return data;
    },
    staleTime: 5 * 60 * 1000,
  });
}

export function useCreateVocabulary() {
  const qc = useQueryClient();

  return useMutation({
    mutationFn: async (body: NewVocabularyRequest) => {
      const { data, error } = await api.POST("/api/admin/vocabularies", { body });

      if (error || !data) throw new Error("create vocabulary failed");

      return data;
    },
    onSuccess: () => qc.invalidateQueries({ queryKey: ["vocabularies"] }),
  });
}

export function useAddTerm() {
  const qc = useQueryClient();

  return useMutation({
    mutationFn: async ({
      vocabularyId,
      external_uri,
      labels,
    }: {
      vocabularyId: string;
      external_uri: string | null;
      labels: LabelInput[];
    }) => {
      const { response } = await api.POST("/api/admin/vocabularies/{id}/terms", {
        params: { path: { id: vocabularyId } },
        body: { external_uri, labels },
      });

      if (response.status !== 201) throw new Error("add term failed");
    },
    onSuccess: (_result, { vocabularyId }) =>
      qc.invalidateQueries({ queryKey: ["terms", vocabularyId] }),
  });
}

export function useCreateAuthority() {
  const qc = useQueryClient();

  return useMutation({
    mutationFn: async ({
      kind,
      external_uri,
      labels,
    }: {
      kind: string;
      external_uri: string | null;
      labels: LabelInput[];
    }) => {
      const { response } = await api.POST("/api/admin/authorities", {
        body: { kind, external_uri, labels },
      });

      if (response.status !== 201) throw new Error("create authority failed");
    },
    onSuccess: (_result, { kind }) =>
      qc.invalidateQueries({ queryKey: ["authorities", kind] }),
  });
}

const SEARCH_PAGE = 20;

export function useSearch(q: string, visibility: string | null) {
  const term = q.trim();

  return useInfiniteQuery({
    queryKey: ["search", term, visibility],
    enabled: term.length > 0,
    initialPageParam: 0,
    queryFn: async ({ pageParam }) => {
      const { data, error, response } = await api.GET("/api/admin/search", {
        params: {
          query: {
            q: term,
            ...(visibility ? { visibility } : {}),
            offset: pageParam,
            limit: SEARCH_PAGE,
          },
        },
      });

      if (error || !data) throw new HttpError(response.status);

      return data;
    },
    placeholderData: keepPreviousData,
    getNextPageParam: (lastPage, allPages) => {
      const loaded = allPages.reduce((n, page) => n + page.hits.length, 0);

      return loaded < lastPage.estimated_total ? loaded : undefined;
    },
  });
}

type NewFieldDefinitionRequest = components["schemas"]["NewFieldDefinitionRequest"];

export function useCreateFieldDefinition() {
  const qc = useQueryClient();

  return useMutation({
    mutationFn: async (body: NewFieldDefinitionRequest) => {
      const { data, response } = await api.POST("/api/admin/field-definitions", { body });

      if (response.status !== 201 || !data) throw new Error("failed to create field definition");

      return data;
    },
    onSuccess: () => qc.invalidateQueries({ queryKey: ["field-definitions"] }),
  });
}

type Visibility = "draft" | "internal" | "public";

/** Error carrying the HTTP status so callers can branch 422-gate vs 409-illegal. */
export class VisibilityError extends Error {
  constructor(public status: number) {
    super(`visibility change failed (${status})`);
    this.name = "VisibilityError";
  }
}

export function useSetVisibility() {
  const qc = useQueryClient();

  return useMutation({
    mutationFn: async ({ id, visibility }: { id: string; visibility: Visibility }) => {
      const { response } = await api.POST("/api/admin/objects/{id}/visibility", {
        params: { path: { id } },
        body: { visibility },
      });

      if (response.status !== 204) throw new VisibilityError(response.status);
    },
    onSuccess: (_result, { id }) => {
      void qc.invalidateQueries({ queryKey: ["object", id] });
      void qc.invalidateQueries({ queryKey: ["objects"] });
    },
  });
}