import { defineStore } from 'pinia'
import { openDB, type IDBPDatabase } from 'idb'

type Track = {
  name: string
  duration?: number
}

type DBTrack = {
  name: string
  blob: Blob
  type?: string
  duration?: number
}

let dbPromise: Promise<IDBPDatabase> | null = null

async function getDB() {
  if (!dbPromise) {
    dbPromise = openDB('repodructor-music', 1, {
      upgrade(db) {
        if (!db.objectStoreNames.contains('tracks')) {
          const store = db.createObjectStore('tracks', { keyPath: 'name' })
          store.createIndex('name', 'name', { unique: true })
        }
      }
    })
  }
  return dbPromise
}

export const useMusicStore = defineStore('music', {
  state: () => ({
    tracks: [] as Track[],
    cachedNames: new Set<string>(),
    loading: false,
    error: null as string | null
  }),
  getters: {
    isCached: (state) => (name: string) => state.cachedNames.has(name)
  },
  actions: {
    async fetchTracks() {
      this.loading = true
      this.error = null
      try {
        const response = await $fetch<{ tracks: Track[] }>('/api/music')
        this.tracks = response.tracks || []
      } catch (e: any) {
        const errorMsg = e?.message || 'Failed to load tracks'
        this.error = errorMsg

        // Check if it's an auth error
        if (e?.statusCode === 401 || e?.statusCode === 403 ||
            errorMsg.includes('401') || errorMsg.includes('403') ||
            errorMsg.includes('Unauthorized')) {
          console.warn('[Music Store] Authentication error detected')
          // The useAuth composable will be notified via watch in components
        }
      } finally {
        this.loading = false
      }
    },

    async loadCachedNames() {
      try {
        const db = await getDB()
        const tx = db.transaction('tracks', 'readonly')
        const store = tx.objectStore('tracks')
        const all = await store.getAllKeys()
        this.cachedNames = new Set((all as string[]) || [])
      } catch (e) {
        // ignore
      }
    },

    async loadCachedTracks(): Promise<Track[]> {
      try {
        const db = await getDB()
        const tx = db.transaction('tracks', 'readonly')
        const store = tx.objectStore('tracks')
        const all = (await store.getAll()) as DBTrack[]
        const names = all.map(t => t.name)
        this.cachedNames = new Set(names)
        const list: Track[] = all.map(t => ({ name: t.name, duration: t.duration }))
        return list
      } catch (e) {
        return []
      }
    },

    async getCachedBlob(name: string): Promise<Blob | null> {
      try {
        const db = await getDB()
        const entry = (await db.get('tracks', name)) as DBTrack | undefined
        if (entry && entry.blob) {
          this.cachedNames.add(name)
          return entry.blob
        }
      } catch (e) {
        // ignore
      }
      return null
    },

    async saveTrackBlob(name: string, blob: Blob, duration?: number) {
      try {
        const db = await getDB()
        const payload: DBTrack = { name, blob, type: blob.type, duration }
        await db.put('tracks', payload)
        this.cachedNames.add(name)
      } catch (e) {
        // ignore
      }
    },

    async deleteCachedTrack(name: string) {
      try {
        const db = await getDB()
        await db.delete('tracks', name)
        this.cachedNames.delete(name)
      } catch (e) {
        // ignore
      }
    },

    // Fetch from API and store in IndexedDB
    async cacheByName(name: string, duration?: number): Promise<boolean> {
      try {
        const encodedName = encodeURIComponent(name)
        const response = await fetch(`/api/music/${encodedName}`)

        if (!response.ok) {
          const errorMsg = `HTTP ${response.status}`

          // Detect authentication errors
          if (response.status === 401 || response.status === 403) {
            console.warn('[Music Store] Cache failed - authentication error:', response.status)
            this.error = `${errorMsg}: Unauthorized - Please log in`
          }

          throw new Error(errorMsg)
        }

        const blob = await response.blob()
        await this.saveTrackBlob(name, blob, duration)
        return true
      } catch (e: any) {
        console.error('[Music Store] Cache failed:', e)
        // Propagate auth errors
        if (e?.message?.includes('401') || e?.message?.includes('403')) {
          this.error = e.message
        }
        return false
      }
    }
  }
})