import type { FollowResponseDto } from '@/api/generated/models'
import {
  createServiceError,
  errorResult,
  handleServiceError,
  type ServiceCallOptions,
  type ServiceResult,
  shouldBubbleErrorToParent,
  successResult,
} from '@/services/errorHandler'
import { unwrapApiData } from '@/services/apiResponse'
import { getOrganizerFollows } from '@/api/generated/organizer-follows/organizer-follows'
import { parseRemittanceList } from '@/helpers/listResponse'
import { texts } from '@/texts'

export interface FollowUserSummary {
  /** Omitted by public follower-list responses. */
  mobile?: string
  firstName: string | null
  lastName: string | null
  avatarUrl?: string | null
  gender?: 'male' | 'female' | 'other' | null
}

export type FollowedOrganizer = Omit<FollowResponseDto, 'user'> & {
  user?: FollowUserSummary
}

const organizerFollowsApi = getOrganizerFollows()

/**
 * `GET /organizers/:id/is-following` — a lightweight boolean check, no
 * `notifyNewEvents` in the response. Per docs/workflows/fa/organizer-follow.md,
 * a freshly-created (or reactivated) follow always starts with
 * notifyNewEvents=true on the backend, so callers show the bell "on" by
 * default; the real value only matters after the user has actually
 * toggled it in this same mounted session (handled client-side, not
 * re-fetched here — see docs/workflows/fa/organizer-follow.md).
 */
export const IS_FOLLOWING_ORGANIZER = async (
  organizerId: string,
  options?: ServiceCallOptions
): Promise<ServiceResult<{ isFollowing: boolean }>> => {
  try {
    const res = await organizerFollowsApi.organizerFollowsControllerIsFollowing(organizerId)
    const raw = res.data

    if ('success' in raw && !raw.success) {
      throw createServiceError(raw.message || texts.profile.fetchFollowStatusFailed)
    }

    // This endpoint isn't wrapped in the usual { success, data } envelope
    // (see organizer-follows.controller.ts), but tolerate either shape.
    const isFollowing = 'isFollowing' in raw ? Boolean(raw.isFollowing) : Boolean(unwrapApiData(raw)?.isFollowing)

    return successResult({ isFollowing })
  } catch (error) {
    const normalizedError = handleServiceError(error, options)

    if (shouldBubbleErrorToParent(options)) {
      throw normalizedError
    }

    return errorResult(normalizedError)
  }
}

export const FOLLOW_ORGANIZER = async (organizerId: string, options?: ServiceCallOptions): Promise<ServiceResult<FollowedOrganizer>> => {
  try {
    const res = await organizerFollowsApi.organizerFollowsControllerFollow(organizerId)
    const payload = res.data

    if (!payload.success) {
      throw createServiceError(payload.message || texts.profile.followFailed)
    }

    const follow = unwrapApiData(payload)

    if (!follow) {
      throw createServiceError(texts.common.invalidServerResponse)
    }

    return successResult(follow)
  } catch (error) {
    const normalizedError = handleServiceError(error, options)

    if (shouldBubbleErrorToParent(options)) {
      throw normalizedError
    }

    return errorResult(normalizedError)
  }
}

export const UNFOLLOW_ORGANIZER = async (
  organizerId: string,
  options?: ServiceCallOptions
): Promise<ServiceResult<{ success: boolean }>> => {
  try {
    const res = await organizerFollowsApi.organizerFollowsControllerUnfollow(organizerId)
    const payload = res.data

    if (!payload.success) {
      throw createServiceError(payload.message || texts.profile.unfollowFailed)
    }

    return successResult({ success: true })
  } catch (error) {
    const normalizedError = handleServiceError(error, options)

    if (shouldBubbleErrorToParent(options)) {
      throw normalizedError
    }

    return errorResult(normalizedError)
  }
}

export const UPDATE_FOLLOW_SETTINGS = async (
  organizerId: string,
  notifyNewEvents: boolean,
  options?: ServiceCallOptions
): Promise<ServiceResult<FollowedOrganizer>> => {
  try {
    const res = await organizerFollowsApi.organizerFollowsControllerUpdateFollowSettings(organizerId, {
      notifyNewEvents,
    })
    const payload = res.data

    if (!payload.success) {
      throw createServiceError(payload.message || texts.profile.updateNotifyFailed)
    }

    const follow = unwrapApiData(payload)

    if (!follow) {
      throw createServiceError(texts.common.invalidServerResponse)
    }

    return successResult(follow)
  } catch (error) {
    const normalizedError = handleServiceError(error, options)

    if (shouldBubbleErrorToParent(options)) {
      throw normalizedError
    }

    return errorResult(normalizedError)
  }
}

/**
 * `GET /organizers/me/following` — paginated. Used both for the
 * `/profile/following` list (page-by-page via `page`) and for the
 * MenuRow badge count (pageSize=1, only `pagination.totalItemsCount` is
 * read — see GET_FOLLOWING_COUNT below).
 */
export const GET_FOLLOWING = async (
  page: number,
  pageSize: number,
  options?: ServiceCallOptions
): Promise<ServiceResult<{ items: FollowedOrganizer[]; totalItemsCount: number }>> => {
  try {
    const res = await organizerFollowsApi.organizerFollowMeControllerGetFollowing({ page, pageSize, sort: '-createdAt' })
    const payload = res.data

    if (!payload.success) {
      throw createServiceError(payload.message || texts.profile.fetchFollowingFailed)
    }

    const { items, pagination } = parseRemittanceList<FollowedOrganizer>(unwrapApiData(payload) ?? {}, 'items', page, pageSize)

    return successResult({ items, totalItemsCount: pagination.totalItemsCount })
  } catch (error) {
    const normalizedError = handleServiceError(error, options)

    if (shouldBubbleErrorToParent(options)) {
      throw normalizedError
    }

    return errorResult(normalizedError)
  }
}

/** Cheap count-only call for the profile MenuRow badge — pageSize=1, discards items. */
export const GET_FOLLOWING_COUNT = async (options?: ServiceCallOptions): Promise<ServiceResult<number>> => {
  const result = await GET_FOLLOWING(1, 1, options)

  if (!result.ok) {
    return result
  }

  return successResult(result.data.totalItemsCount)
}

/**
 * `GET /organizers/me/followers` — users following the current user as an
 * organizer/host. Only meaningful for verified hosts (see
 * `HostCapabilityService.isVerifiedHost` — non-hosts simply have no
 * followers, so this returns an empty list rather than erroring).
 */
export const GET_FOLLOWERS = async (
  page: number,
  pageSize: number,
  options?: ServiceCallOptions
): Promise<ServiceResult<{ items: FollowedOrganizer[]; totalItemsCount: number }>> => {
  try {
    const res = await organizerFollowsApi.organizerFollowMeControllerGetFollowers({ page, pageSize, sort: '-createdAt' })
    const payload = res.data

    if (!payload.success) {
      throw createServiceError(payload.message || texts.profile.fetchFollowersFailed)
    }

    const { items, pagination } = parseRemittanceList<FollowedOrganizer>(unwrapApiData(payload) ?? {}, 'items', page, pageSize)

    return successResult({ items, totalItemsCount: pagination.totalItemsCount })
  } catch (error) {
    const normalizedError = handleServiceError(error, options)

    if (shouldBubbleErrorToParent(options)) {
      throw normalizedError
    }

    return errorResult(normalizedError)
  }
}