import { db } from './db.js'

async function getToken() {
  const session = await db.session.get(1)
  return session?.token ?? null
}

export async function apiFetch(path, options = {}) {
  const token = await getToken()
  const headers = {}
  // Don't set Content-Type for FormData — browser sets it with correct boundary
  if (!(options.body instanceof FormData)) {
    headers['Content-Type'] = 'application/json'
  }
  Object.assign(headers, options.headers)
  if (token) headers['Authorization'] = `Bearer ${token}`

  const res = await fetch(path, { ...options, headers })
  if (res.status === 401) {
    await db.session.clear()
    window.location.hash = '#/login'
    throw new Error('unauthorized')
  }
  return res
}

export async function apiJSON(path, options = {}) {
  const res = await apiFetch(path, options)
  if (!res.ok) {
    const err = await res.json().catch(() => ({ error: res.statusText }))
    throw new Error(err.error || res.statusText)
  }
  return res.json()
}

// Unauthenticated fetch for the kiosk (no JWT, no redirect on 401)
async function kioskFetch(path, options = {}) {
  const headers = { 'Content-Type': 'application/json', ...options.headers }
  const res = await fetch(path, { ...options, headers })
  if (!res.ok) {
    const err = await res.json().catch(() => ({ error: res.statusText }))
    const e = new Error(err.error || res.statusText)
    e.status = res.status
    e.body = err
    throw e
  }
  return res.json()
}

export const api = {
  login: (username, password) =>
    apiJSON('/api/login', { method: 'POST', body: JSON.stringify({ username, password }) }),
  logout: () => apiFetch('/api/logout', { method: 'POST' }),
  me: () => apiJSON('/api/me'),
  event: {
    get: () => apiJSON('/api/event'),
    update: (data) => apiJSON('/api/event', { method: 'PUT', body: JSON.stringify(data) }),
  },
  attendees: {
    list: (params = {}) => apiJSON('/api/attendees?' + new URLSearchParams(params)),
    get: (id) => apiJSON(`/api/attendees/${id}`),
    create: (data) => apiJSON('/api/attendees', { method: 'POST', body: JSON.stringify(data) }),
    update: (id, data) => apiJSON(`/api/attendees/${id}`, { method: 'PUT', body: JSON.stringify(data) }),
    delete: (id) => apiFetch(`/api/attendees/${id}`, { method: 'DELETE' }),
    checkIn: (id, opts = {}) =>
      apiJSON(`/api/attendees/${id}/checkin`, { method: 'POST', body: JSON.stringify(opts) }),
    generateTokens: () =>
      apiJSON('/api/attendees/generate-tokens', { method: 'POST' }),
    emailToken: (id) =>
      apiJSON(`/api/attendees/${id}/email-token`, { method: 'POST' }),
    emailAllTokens: () =>
      apiJSON('/api/attendees/email-tokens', { method: 'POST' }),
  },
  volunteers: {
    list: (params = {}) => apiJSON('/api/volunteers?' + new URLSearchParams(params)),
    get: (id) => apiJSON(`/api/volunteers/${id}`),
    create: (data) => apiJSON('/api/volunteers', { method: 'POST', body: JSON.stringify(data) }),
    update: (id, data) => apiJSON(`/api/volunteers/${id}`, { method: 'PUT', body: JSON.stringify(data) }),
    delete: (id) => apiFetch(`/api/volunteers/${id}`, { method: 'DELETE' }),
    checkIn: (id) => apiJSON(`/api/volunteers/${id}/checkin`, { method: 'POST' }),
    assignShift: (id, shiftId) => apiFetch(`/api/volunteers/${id}/shifts`, { method: 'POST', body: JSON.stringify({ shift_id: shiftId }) }),
    unassignShift: (id, shiftId) => apiFetch(`/api/volunteers/${id}/shifts/${shiftId}`, { method: 'DELETE' }),
  },
  departments: {
    list: () => apiJSON('/api/departments'),
    create: (data) => apiJSON('/api/departments', { method: 'POST', body: JSON.stringify(data) }),
    update: (id, data) => apiJSON(`/api/departments/${id}`, { method: 'PUT', body: JSON.stringify(data) }),
    delete: (id) => apiFetch(`/api/departments/${id}`, { method: 'DELETE' }),
  },
  shifts: {
    list: (params = {}) => apiJSON('/api/shifts?' + new URLSearchParams(params)),
    create: (data) => apiJSON('/api/shifts', { method: 'POST', body: JSON.stringify(data) }),
    update: (id, data) => apiJSON(`/api/shifts/${id}`, { method: 'PUT', body: JSON.stringify(data) }),
    delete: (id) => apiFetch(`/api/shifts/${id}`, { method: 'DELETE' }),
    assignVolunteer: (shiftId, volunteerId, force = false) =>
      apiFetch(`/api/shifts/${shiftId}/volunteers`, { method: 'POST', body: JSON.stringify({ volunteer_id: volunteerId, force }) }),
    unassignVolunteer: (shiftId, volunteerId) =>
      apiFetch(`/api/shifts/${shiftId}/volunteers/${volunteerId}`, { method: 'DELETE' }),
    reorder: (positions) =>
      apiFetch('/api/shifts/reorder', { method: 'POST', body: JSON.stringify(positions) }),
  },
  users: {
    list: () => apiJSON('/api/users'),
    create: (data) => apiJSON('/api/users', { method: 'POST', body: JSON.stringify(data) }),
    update: (id, data) => apiJSON(`/api/users/${id}`, { method: 'PUT', body: JSON.stringify(data) }),
    delete: (id) => apiFetch(`/api/users/${id}`, { method: 'DELETE' }),
  },
  settings: {
    get: () => apiJSON('/api/settings'),
    update: (data) => apiJSON('/api/settings', { method: 'PUT', body: JSON.stringify(data) }),
    testEmail: (to) => apiJSON('/api/settings/test-email', { method: 'POST', body: JSON.stringify({ to }) }),
  },
  import: async (formData) => {
    const res = await apiFetch('/api/import', { method: 'POST', body: formData })
    if (!res.ok) {
      const err = await res.json().catch(() => ({ error: res.statusText }))
      throw new Error(err.error || res.statusText)
    }
    return res.json()
  },
  sync: {
    pull: (since) => apiJSON('/api/sync/pull' + (since ? `?since=${encodeURIComponent(since)}` : '')),
  },
  kiosk: {
    get: (token) => kioskFetch(`/api/v/${token}`),
    // claim returns {conflict: true, conflicting_shifts: [...]} on 409, or the updated kiosk state on success.
    claim: async (token, shiftId, force = false) => {
      const res = await fetch(`/api/v/${token}/shifts/${shiftId}${force ? '?force=true' : ''}`, {
        method: 'POST',
        headers: { 'Content-Type': 'application/json' },
      })
      const body = await res.json().catch(() => ({}))
      if (res.status === 409) return { conflict: true, ...body }
      if (!res.ok) throw new Error(body.error || res.statusText)
      return body
    },
    unclaim: (token, shiftId) =>
      kioskFetch(`/api/v/${token}/shifts/${shiftId}`, { method: 'DELETE' }),
  },
}