import { atom, map, computed, onMount } from 'nanostores'
import { createFetcherStore, createBlogMutatorStore } from './fetcher'
import type { InteractionConfig } from '../types'

const defaultConfig: InteractionConfig = {
  comments_enabled: false,
  reactions_enabled: false,
  reaction_mode: 'emoji',
  reaction_emojis: '👍,❤️,🎉,🚀',
  upvote_icon: 'arrow',
  reactions_require_auth: false,
}

export const $interactionsData = createFetcherStore<InteractionConfig>(['/api/studio/interaction-config'])

export const $interactions = map<InteractionConfig>({ ...defaultConfig })
export const $initialInteractions = atom<InteractionConfig | null>(null)

export const $hasInteractionChanges = computed(
  [$interactions, $initialInteractions],
  (current, initial) => initial !== null && JSON.stringify(current) !== JSON.stringify(initial)
)

export const $changedInteractionFields = computed(
  [$interactions, $initialInteractions],
  (current, initial) => {
    if (!initial) return []
    const changes: string[] = []
    const labels: Record<string, string> = {
      comments_enabled: 'Comments',
      reactions_enabled: 'Reactions',
      reaction_mode: 'Reaction mode',
      reaction_emojis: 'Emojis',
      upvote_icon: 'Upvote icon',
      reactions_require_auth: 'Auth required',
    }
    for (const key of Object.keys(current) as (keyof InteractionConfig)[]) {
      if (current[key] !== initial[key]) {
        changes.push(labels[key] || key)
      }
    }
    return changes
  }
)

onMount($interactionsData, () => {
  $interactionsData.listen(({ data }) => {
    if (data) {
      const merged = { ...defaultConfig, ...data }
      $interactions.set(merged)
      $initialInteractions.set(merged)
    }
  })
})

export const $saveInteractions = createBlogMutatorStore<InteractionConfig>(
  async ({ data: config }) => {
    const previous = $initialInteractions.get()
    $initialInteractions.set({ ...config })

    const res = await fetch('/api/studio/interaction-config', {
      method: 'PUT',
      headers: { 'Content-Type': 'application/json' },
      body: JSON.stringify(config),
    })

    if (!res.ok) {
      $initialInteractions.set(previous)
      throw new Error('Failed to save interactions')
    }

    return config
  }
)