const nbt = require('prismarine-nbt')
const mcNamespace = 'minecraft:'

function inject (bot) {
  bot.core = {
    size: { start: { x: 0, y: 0, z: 0 }, end: { x: 15, y: 0, z: 15 } },

    start: { x: null, y: null, z: null },
    end: { x: null, y: null, z: null },

    block: { x: null, y: null, z: null },

    refill () {
      const refillCommand = `/fill ${this.start.x} ${this.start.y} ${this.start.z} ${this.end.x} ${this.end.y} ${this.end.z} repeating_command_block{CustomName:'""'}`
      const location = { x: Math.floor(bot.position.x), y: Math.floor(bot.position.y) - 1, z: Math.floor(bot.position.z) }
      const commandBlockId = bot.registry?.itemsByName.command_block.id

      bot._client.write('set_creative_slot', {
        slot: 36,
        item: {
          present: true,
          itemId: commandBlockId,
          itemCount: 1,
          nbtData: nbt.comp({
            BlockEntityTag: nbt.comp({
              auto: nbt.byte(1),
              Command: nbt.string(refillCommand)
            })
          })
        }
      })

      bot._client.write('block_dig', {
        status: 0,
        location,
        face: 1
      })

      bot._client.write('block_place', {
         location,
         direction: 1,
         hand: 0,
         cursorX: 0.5,
         cursorY: 0.5,
         cursorZ: 0.5,
         insideBlock: false
      })
    },

    run (command) {
      if (!bot.loggedIn) return
      if (!bot.features.commandNamespaces && command.startsWith(mcNamespace)) command = command.substring(mcNamespace.length)

      if (bot.features.amnesicCommandBlocks) bot._client.write('update_command_block', { location: this.block, command: '', mode: 0, flags: 0b000 })
      bot._client.write('update_command_block', { location: this.block, command: String(command).substring(0, 32767), mode: bot.features.amnesicCommandBlocks ? 1 : 2, flags: 0b100 })

      this.block.x++
      if (this.block.x > this.end.x) {
        this.block.x = this.start.x
        this.block.z++
      }

      if (this.block.z > this.end.z) {
        this.block.z = this.start.z
        this.block.y++
      }

      if (this.block.y > this.end.y) {
        this.block.x = this.start.x
        this.block.y = this.start.y
        this.block.z = this.start.z
      }
    },

    reset () {
      const x = (bot.position.x >> 4) << 4
      const y = 0
      const z = (bot.position.z >> 4) << 4

      this.start = { x: this.size.start.x + x, y: this.size.start.y + y, z: this.size.start.z + z }
      this.end = { x: this.size.end.x + x, y: this.size.end.y + y, z: this.size.end.z + z }
      this.block = { ...this.start }
      this.refill()
    }
  }
  bot.on('move', oldPos => {
    bot.core.run(`minecraft:setblock ${Math.floor(oldPos.x)} ${Math.floor(oldPos.y - 1)} ${Math.floor(oldPos.z)} minecraft:air replace mincecraft:command:block`) // Clean up after refills
    bot.core.reset()
  })
  setInterval(() => bot.core.refill(), 60 * 1000)
}

module.exports = inject