import { ensureOk, IHttpClient } from '../../services/http/IHttpClient';
import { getJson, listItemsUrl } from '../../shared/sharepoint/spRest';
import { LISTS, ListTitle } from '../../config/lists';
import {
  IAssignedResource,
  IProjectResources,
  IResourceItem,
  ISpAssignedRow,
  ISpResourceRow,
  ResourceKind
} from './resourcesTypes';

// Запросы раздела — 1:1 со stroy-bot-project-assigner (useProjectResources).
// Там был PnPjs v4; здесь те же запросы через SharePoint REST:
// - fetchAll (async-итератор PnP) → проход по odata.nextLink до конца;
// - items.add → POST в items с тем же телом;
// - item.delete → POST с X-HTTP-Method: DELETE и IF-MATCH: * (так делает сам PnP).

/** Поле lookup на проект в списках привязок (в $filter — `{поле}Id`). */
const PROJECT_LOOKUP_ID_FIELD = 'projectIdId';

interface IResourceListConfig {
  /** Справочник: «Профессии» / «Компании». */
  poolList: ListTitle;
  /** Привязки к проекту: «Профессии по проекту» / «Компании по проекту». */
  assignedList: ListTitle;
  /** Lookup на справочник: в $select/$expand читается `{поле}/Id`, при записи — `{поле}Id`. */
  lookupField: 'professionId' | 'companyId';
}

export const RESOURCE_LISTS: Record<ResourceKind, IResourceListConfig> = {
  professions: {
    poolList: LISTS.professions,
    assignedList: LISTS.professionsByProject,
    lookupField: 'professionId'
  },
  companies: {
    poolList: LISTS.companies,
    assignedList: LISTS.companiesByProject,
    lookupField: 'companyId'
  }
};

/**
 * Заголовки записи. odata=nometadata — тело без `__metadata` (как отправляет PnP v4);
 * пустой odata-version отключает OData 4.0 от SPHttpClient — тот же приём,
 * что в stroy-bot-projects-binder, проверенный на этом сайте.
 */
export const SP_WRITE_HEADERS: Record<string, string> = {
  Accept: 'application/json;odata=nometadata',
  'Content-Type': 'application/json;odata=nometadata',
  'odata-version': ''
};

export const SP_DELETE_HEADERS: Record<string, string> = {
  'X-HTTP-Method': 'DELETE',
  'IF-MATCH': '*'
};

export function projectTitleUrl(siteUrl: string, projectId: string): string {
  return `${listItemsUrl(siteUrl, LISTS.projects)}(${Number(projectId)})?$select=Title`;
}

export function poolItemsUrl(siteUrl: string, kind: ResourceKind): string {
  return `${listItemsUrl(siteUrl, RESOURCE_LISTS[kind].poolList)}?$select=Id,Title`;
}

export function assignedItemsUrl(siteUrl: string, kind: ResourceKind, projectId: string): string {
  const { assignedList, lookupField } = RESOURCE_LISTS[kind];
  return (
    `${listItemsUrl(siteUrl, assignedList)}` +
    `?$select=Id,Title,${lookupField}/Id` +
    `&$expand=${lookupField}` +
    `&$filter=${PROJECT_LOOKUP_ID_FIELD} eq ${projectId}`
  );
}

export function assignedItemUrl(siteUrl: string, kind: ResourceKind, itemId: number): string {
  return `${listItemsUrl(siteUrl, RESOURCE_LISTS[kind].assignedList)}(${itemId})`;
}

interface ISpPage<T> {
  value: T[];
  'odata.nextLink'?: string;
  '@odata.nextLink'?: string;
}

/** Все страницы коллекции: SharePoint отдаёт по 100 строк и ссылку на следующую страницу. */
export async function fetchAllItems<T>(client: IHttpClient, url: string): Promise<T[]> {
  const items: T[] = [];
  let nextUrl: string | undefined = url;
  while (nextUrl) {
    const page: ISpPage<T> = await getJson<ISpPage<T>>(client, nextUrl);
    items.push(...page.value);
    nextUrl = page['@odata.nextLink'] ?? page['odata.nextLink'];
  }
  return items;
}

function toAssigned(row: ISpAssignedRow, kind: ResourceKind): IAssignedResource {
  const lookup = row[RESOURCE_LISTS[kind].lookupField];
  return { id: row.Id, title: row.Title, referenceId: lookup?.Id ?? 0 };
}

function toResourceItem(row: ISpResourceRow): IResourceItem {
  return { id: row.Id, title: row.Title };
}

/** Название проекта, оба справочника и обе привязки — параллельно, как в assigner. */
export async function fetchProjectResources(
  client: IHttpClient,
  siteUrl: string,
  projectId: string
): Promise<IProjectResources> {
  const [project, professions, companies, assignedProfessions, assignedCompanies] = await Promise.all([
    getJson<{ Title: string }>(client, projectTitleUrl(siteUrl, projectId)),
    fetchAllItems<ISpResourceRow>(client, poolItemsUrl(siteUrl, 'professions')),
    fetchAllItems<ISpResourceRow>(client, poolItemsUrl(siteUrl, 'companies')),
    fetchAllItems<ISpAssignedRow>(client, assignedItemsUrl(siteUrl, 'professions', projectId)),
    fetchAllItems<ISpAssignedRow>(client, assignedItemsUrl(siteUrl, 'companies', projectId))
  ]);

  return {
    projectName: project.Title,
    pools: { professions: professions.map(toResourceItem), companies: companies.map(toResourceItem) },
    assigned: {
      professions: assignedProfessions.map((row) => toAssigned(row, 'professions')),
      companies: assignedCompanies.map((row) => toAssigned(row, 'companies'))
    }
  };
}

/** Создаёт привязку и возвращает id новой записи. */
export async function addAssignedResource(
  client: IHttpClient,
  siteUrl: string,
  kind: ResourceKind,
  projectId: string,
  item: IResourceItem
): Promise<number> {
  const body = {
    Title: item.title,
    [PROJECT_LOOKUP_ID_FIELD]: Number(projectId),
    [`${RESOURCE_LISTS[kind].lookupField}Id`]: item.id
  };
  const response = await ensureOk(
    await client.fetch(listItemsUrl(siteUrl, RESOURCE_LISTS[kind].assignedList), {
      method: 'POST',
      headers: SP_WRITE_HEADERS,
      body: JSON.stringify(body)
    })
  );
  const created = (await response.json()) as { Id: number };
  return created.Id;
}

export async function deleteAssignedResource(
  client: IHttpClient,
  siteUrl: string,
  kind: ResourceKind,
  itemId: number
): Promise<void> {
  await ensureOk(
    await client.fetch(assignedItemUrl(siteUrl, kind, itemId), { method: 'POST', headers: SP_DELETE_HEADERS })
  );
}