import type {
  AdminDashboardGrowthStats,
  AdminDashboardOperationsStats,
  AdminDashboardOverviewStats,
  AdminDashboardSharingStats,
  AdminDashboardStorageStats,
  AdminDashboardTrafficStats,
} from '@shared/types'
import { addCalendarDays, statsDayKey, utcDateStart } from '../domain/admin-stats-time'
import { type AdminStatsDateRange, type AdminStatsRepo, badRequest } from './ports'

export type AdminStatsDeps = {
  adminStats: AdminStatsRepo
}

export interface AdminStatsRangeInput {
  from?: Date
  to?: Date
  timeZone?: 'UTC'
}

const MAX_DASHBOARD_RANGE_DAYS = 366
export function normalizeStatsRange(input: AdminStatsRangeInput, now = new Date()): AdminStatsDateRange {
  const timeZone = input.timeZone ?? 'UTC'
  if (timeZone !== 'UTC') throw badRequest('admin analytics uses UTC calendar boundaries', 'UNSUPPORTED_TIME_ZONE')
  const today = statsDayKey(now)
  const to = input.to ?? new Date(utcDateStart(addCalendarDays(today, 1)).getTime() - 1)
  const from = input.from ?? utcDateStart(addCalendarDays(statsDayKey(to), -29))
  if (from > to) throw badRequest('from must be before to', 'INVALID_TIME_RANGE')
  if (from.getUTCMinutes() !== 0 || from.getUTCSeconds() !== 0 || from.getUTCMilliseconds() !== 0) {
    throw badRequest('from must align to a UTC hour', 'INVALID_TIME_RANGE')
  }
  const toExclusive = to.getTime() + 1
  if (toExclusive % 3_600_000 !== 0) {
    throw badRequest('to must end on a UTC hour', 'INVALID_TIME_RANGE')
  }
  if (calendarDayCount(from, to) > MAX_DASHBOARD_RANGE_DAYS) {
    throw badRequest(`time range cannot exceed ${MAX_DASHBOARD_RANGE_DAYS} days`, 'TIME_RANGE_TOO_LARGE')
  }
  const currentHourStart = Math.floor(now.getTime() / 3_600_000) * 3_600_000
  if (from.getTime() >= currentHourStart) {
    throw badRequest('time range must include a closed UTC hour', 'INVALID_TIME_RANGE')
  }
  return { from, to, timeZone }
}

export function getAdminDashboardOverviewStats(
  deps: AdminStatsDeps,
  input: AdminStatsRangeInput,
  now = new Date(),
): Promise<AdminDashboardOverviewStats> {
  return deps.adminStats.getDashboardOverviewStats(now, normalizeStatsRange(input, now))
}

export function getAdminDashboardOperationsStats(
  deps: AdminStatsDeps,
  input: AdminStatsRangeInput,
  now = new Date(),
): Promise<AdminDashboardOperationsStats> {
  return deps.adminStats.getDashboardOperationsStats(now, normalizeStatsRange(input, now))
}

export function getAdminDashboardGrowthStats(
  deps: AdminStatsDeps,
  input: AdminStatsRangeInput,
  now = new Date(),
): Promise<AdminDashboardGrowthStats> {
  return deps.adminStats.getDashboardGrowthStats(now, normalizeStatsRange(input, now))
}

export function getAdminDashboardStorageStats(
  deps: AdminStatsDeps,
  input: AdminStatsRangeInput,
  now = new Date(),
): Promise<AdminDashboardStorageStats> {
  return deps.adminStats.getDashboardStorageStats(now, normalizeStatsRange(input, now))
}

export function getAdminDashboardTrafficStats(
  deps: AdminStatsDeps,
  input: AdminStatsRangeInput,
  now = new Date(),
): Promise<AdminDashboardTrafficStats> {
  return deps.adminStats.getDashboardTrafficStats(now, normalizeStatsRange(input, now))
}

export function getAdminDashboardSharingStats(
  deps: AdminStatsDeps,
  input: AdminStatsRangeInput,
  now = new Date(),
): Promise<AdminDashboardSharingStats> {
  return deps.adminStats.getDashboardSharingStats(now, normalizeStatsRange(input, now))
}

function calendarDayCount(from: Date, to: Date): number {
  const fromDay = Date.parse(`${statsDayKey(from)}T00:00:00.000Z`)
  const toDay = Date.parse(`${statsDayKey(to)}T00:00:00.000Z`)
  return Math.floor((toDay - fromDay) / 86_400_000) + 1
}