import { create } from 'zustand'
import apiClient from '../api/client'
import type { AxiosResponse } from 'axios'
import type { VacayPlan, VacayUser, VacayEntry, VacayStat, HolidaysMap, HolidayInfo, VacayHolidayCalendar } from '../types'

const ax = apiClient

interface PendingInvite {
  user_id: number
  username: string
}

interface IncomingInvite {
  plan_id: number
  owner_username: string
}

interface VacayPlanResponse {
  plan: VacayPlan
  users: VacayUser[]
  pendingInvites: PendingInvite[]
  incomingInvites: IncomingInvite[]
  isOwner: boolean
  isFused: boolean
}

interface VacayYearsResponse {
  years: number[]
}

interface VacayEntriesResponse {
  entries: VacayEntry[]
  companyHolidays: string[]
}

interface VacayStatsResponse {
  stats: VacayStat[]
}

interface VacayHolidayRaw {
  date: string
  name: string
  localName: string
  global: boolean
  counties: string[] | null
}

interface VacayApi {
  getPlan: () => Promise<VacayPlanResponse>
  updatePlan: (data: Partial<VacayPlan>) => Promise<{ plan: VacayPlan }>
  updateColor: (color: string, targetUserId?: number) => Promise<unknown>
  invite: (userId: number) => Promise<unknown>
  acceptInvite: (planId: number) => Promise<unknown>
  declineInvite: (planId: number) => Promise<unknown>
  cancelInvite: (userId: number) => Promise<unknown>
  dissolve: () => Promise<unknown>
  availableUsers: () => Promise<{ users: VacayUser[] }>
  getYears: () => Promise<VacayYearsResponse>
  addYear: (year: number) => Promise<VacayYearsResponse>
  removeYear: (year: number) => Promise<VacayYearsResponse>
  getEntries: (year: number) => Promise<VacayEntriesResponse>
  toggleEntry: (date: string, targetUserId?: number) => Promise<unknown>
  toggleCompanyHoliday: (date: string) => Promise<unknown>
  getStats: (year: number) => Promise<VacayStatsResponse>
  updateStats: (year: number, days: number, targetUserId?: number) => Promise<unknown>
  getCountries: () => Promise<{ countries: string[] }>
  getHolidays: (year: number, country: string) => Promise<VacayHolidayRaw[]>
  addHolidayCalendar: (data: { region: string; color?: string; label?: string | null }) => Promise<{ calendar: VacayHolidayCalendar }>
  updateHolidayCalendar: (id: number, data: { region?: string; color?: string; label?: string | null }) => Promise<{ calendar: VacayHolidayCalendar }>
  deleteHolidayCalendar: (id: number) => Promise<unknown>
}

const api: VacayApi = {
  getPlan: () => ax.get('/addons/vacay/plan').then((r: AxiosResponse) => r.data),
  updatePlan: (data) => ax.put('/addons/vacay/plan', data).then((r: AxiosResponse) => r.data),
  updateColor: (color, targetUserId) => ax.put('/addons/vacay/color', { color, target_user_id: targetUserId }).then((r: AxiosResponse) => r.data),
  invite: (userId) => ax.post('/addons/vacay/invite', { user_id: userId }).then((r: AxiosResponse) => r.data),
  acceptInvite: (planId) => ax.post('/addons/vacay/invite/accept', { plan_id: planId }).then((r: AxiosResponse) => r.data),
  declineInvite: (planId) => ax.post('/addons/vacay/invite/decline', { plan_id: planId }).then((r: AxiosResponse) => r.data),
  cancelInvite: (userId) => ax.post('/addons/vacay/invite/cancel', { user_id: userId }).then((r: AxiosResponse) => r.data),
  dissolve: () => ax.post('/addons/vacay/dissolve').then((r: AxiosResponse) => r.data),
  availableUsers: () => ax.get('/addons/vacay/available-users').then((r: AxiosResponse) => r.data),
  getYears: () => ax.get('/addons/vacay/years').then((r: AxiosResponse) => r.data),
  addYear: (year) => ax.post('/addons/vacay/years', { year }).then((r: AxiosResponse) => r.data),
  removeYear: (year) => ax.delete(`/addons/vacay/years/${year}`).then((r: AxiosResponse) => r.data),
  getEntries: (year) => ax.get(`/addons/vacay/entries/${year}`).then((r: AxiosResponse) => r.data),
  toggleEntry: (date, targetUserId) => ax.post('/addons/vacay/entries/toggle', { date, target_user_id: targetUserId }).then((r: AxiosResponse) => r.data),
  toggleCompanyHoliday: (date) => ax.post('/addons/vacay/entries/company-holiday', { date }).then((r: AxiosResponse) => r.data),
  getStats: (year) => ax.get(`/addons/vacay/stats/${year}`).then((r: AxiosResponse) => r.data),
  updateStats: (year, days, targetUserId) => ax.put(`/addons/vacay/stats/${year}`, { vacation_days: days, target_user_id: targetUserId }).then((r: AxiosResponse) => r.data),
  getCountries: () => ax.get('/addons/vacay/holidays/countries').then((r: AxiosResponse) => r.data),
  getHolidays: (year, country) => ax.get(`/addons/vacay/holidays/${year}/${country}`).then((r: AxiosResponse) => r.data),
  addHolidayCalendar: (data) => ax.post('/addons/vacay/plan/holiday-calendars', data).then((r: AxiosResponse) => r.data),
  updateHolidayCalendar: (id, data) => ax.put(`/addons/vacay/plan/holiday-calendars/${id}`, data).then((r: AxiosResponse) => r.data),
  deleteHolidayCalendar: (id) => ax.delete(`/addons/vacay/plan/holiday-calendars/${id}`).then((r: AxiosResponse) => r.data),
}

interface VacayState {
  plan: VacayPlan | null
  users: VacayUser[]
  pendingInvites: PendingInvite[]
  incomingInvites: IncomingInvite[]
  isOwner: boolean
  isFused: boolean
  years: number[]
  entries: VacayEntry[]
  companyHolidays: string[]
  stats: VacayStat[]
  selectedYear: number
  selectedUserId: number | null
  holidays: HolidaysMap
  loading: boolean

  setSelectedYear: (year: number) => void
  setSelectedUserId: (id: number | null) => void
  loadPlan: () => Promise<void>
  updatePlan: (updates: Partial<VacayPlan>) => Promise<void>
  updateColor: (color: string, targetUserId?: number) => Promise<void>
  invite: (userId: number) => Promise<void>
  acceptInvite: (planId: number) => Promise<void>
  declineInvite: (planId: number) => Promise<void>
  cancelInvite: (userId: number) => Promise<void>
  dissolve: () => Promise<void>
  loadYears: () => Promise<void>
  addYear: (year: number) => Promise<void>
  removeYear: (year: number) => Promise<void>
  loadEntries: (year?: number) => Promise<void>
  toggleEntry: (date: string, targetUserId?: number) => Promise<void>
  toggleCompanyHoliday: (date: string) => Promise<void>
  loadStats: (year?: number) => Promise<void>
  updateVacationDays: (year: number, days: number, targetUserId?: number) => Promise<void>
  loadHolidays: (year?: number) => Promise<void>
  addHolidayCalendar: (data: { region: string; color?: string; label?: string | null }) => Promise<void>
  updateHolidayCalendar: (id: number, data: { region?: string; color?: string; label?: string | null }) => Promise<void>
  deleteHolidayCalendar: (id: number) => Promise<void>
  loadAll: () => Promise<void>
}

export const useVacayStore = create<VacayState>((set, get) => ({
  plan: null,
  users: [],
  pendingInvites: [],
  incomingInvites: [],
  isOwner: true,
  isFused: false,
  years: [],
  entries: [],
  companyHolidays: [],
  stats: [],
  selectedYear: new Date().getFullYear(),
  selectedUserId: null,
  holidays: {},
  loading: false,

  setSelectedYear: (year: number) => set({ selectedYear: year }),
  setSelectedUserId: (id: number | null) => set({ selectedUserId: id }),

  loadPlan: async () => {
    const data = await api.getPlan()
    set({
      plan: data.plan,
      users: data.users,
      pendingInvites: data.pendingInvites,
      incomingInvites: data.incomingInvites,
      isOwner: data.isOwner,
      isFused: data.isFused,
    })
  },

  updatePlan: async (updates: Partial<VacayPlan>) => {
    const data = await api.updatePlan(updates)
    set({ plan: data.plan })
    await get().loadEntries()
    await get().loadStats()
    await get().loadHolidays()
  },

  updateColor: async (color: string, targetUserId?: number) => {
    await api.updateColor(color, targetUserId)
    await get().loadPlan()
    await get().loadEntries()
  },

  invite: async (userId: number) => {
    await api.invite(userId)
    await get().loadPlan()
  },

  acceptInvite: async (planId: number) => {
    await api.acceptInvite(planId)
    await get().loadAll()
  },

  declineInvite: async (planId: number) => {
    await api.declineInvite(planId)
    await get().loadPlan()
  },

  cancelInvite: async (userId: number) => {
    await api.cancelInvite(userId)
    await get().loadPlan()
  },

  dissolve: async () => {
    await api.dissolve()
    await get().loadAll()
  },

  loadYears: async () => {
    const data = await api.getYears()
    set({ years: data.years })
    if (data.years.length > 0) {
      set({ selectedYear: data.years[data.years.length - 1] })
    }
  },

  addYear: async (year: number) => {
    const data = await api.addYear(year)
    set({ years: data.years })
    await get().loadStats(year)
  },

  removeYear: async (year: number) => {
    const data = await api.removeYear(year)
    set({ years: data.years })
  },

  loadEntries: async (year?: number) => {
    const y = year || get().selectedYear
    const data = await api.getEntries(y)
    set({ entries: data.entries, companyHolidays: data.companyHolidays })
  },

  toggleEntry: async (date: string, targetUserId?: number) => {
    await api.toggleEntry(date, targetUserId)
    await get().loadEntries()
    await get().loadStats()
  },

  toggleCompanyHoliday: async (date: string) => {
    await api.toggleCompanyHoliday(date)
    await get().loadEntries()
  },

  loadStats: async (year?: number) => {
    const y = year || get().selectedYear
    const data = await api.getStats(y)
    set({ stats: data.stats })
  },

  updateVacationDays: async (year: number, days: number, targetUserId?: number) => {
    await api.updateStats(year, days, targetUserId)
    await get().loadStats(year)
  },

  loadHolidays: async (year?: number) => {
    const y = year || get().selectedYear
    const plan = get().plan
    const calendars = plan?.holiday_calendars ?? []
    if (!plan?.holidays_enabled || calendars.length === 0) {
      set({ holidays: {} })
      return
    }
    const map: HolidaysMap = {}
    for (const cal of calendars) {
      const country = cal.region.split('-')[0]
      const region = cal.region.includes('-') ? cal.region : null
      try {
        const data = await api.getHolidays(y, country)
        const hasRegions = data.some((h: VacayHolidayRaw) => h.counties && h.counties.length > 0)
        if (hasRegions && !region) continue
        data.forEach((h: VacayHolidayRaw) => {
          if (h.global || !h.counties || (region && h.counties.includes(region))) {
            if (!map[h.date]) {
              map[h.date] = { name: h.name, localName: h.localName, color: cal.color, label: cal.label }
            }
          }
        })
      } catch { /* API error, skip */ }
    }
    set({ holidays: map })
  },

  addHolidayCalendar: async (data) => {
    await api.addHolidayCalendar(data)
    await get().loadPlan()
    await get().loadHolidays()
  },

  updateHolidayCalendar: async (id, data) => {
    await api.updateHolidayCalendar(id, data)
    await get().loadPlan()
    await get().loadHolidays()
  },

  deleteHolidayCalendar: async (id) => {
    await api.deleteHolidayCalendar(id)
    await get().loadPlan()
    await get().loadHolidays()
  },

  loadAll: async () => {
    set({ loading: true })
    try {
      await get().loadPlan()
      await get().loadYears()
      const year = get().selectedYear
      await get().loadEntries(year)
      await get().loadStats(year)
      await get().loadHolidays(year)
    } finally {
      set({ loading: false })
    }
  },
}))