const {
	mockReply
} = require('../../services/ai/mock')

const HINTS = [
	'今晚还有空桌吗？',
	'热销菜品有哪些？',
	'今天预订情况怎么样？',
	'帮我查一下订单',
]

let typingTimer = null
let recTimer = null
let recStart = 0
let touchStartY = 0
let stopped = false
let recordToken = 0
let recorderBound = false
const recorder = wx.getRecorderManager()

function bindRecorder() {
	if (recorderBound) return
	recorderBound = true
	recorder.onStop((res) => {
		const pages = getCurrentPages()
		const page = pages[pages.length - 1]
		if (page && typeof page.handleRecordStop === 'function') {
			page.handleRecordStop(res)
		}
	})
	recorder.onError((err) => {
		const pages = getCurrentPages()
		const page = pages[pages.length - 1]
		if (page && typeof page.handleRecordError === 'function') {
			page.handleRecordError(err)
		}
	})
}

function pad2(n) {
	return n < 10 ? `0${n}` : `${n}`
}

function timeStr(date) {
	date = date || new Date()
	return `${pad2(date.getHours())}:${pad2(date.getMinutes())}`
}

function uid() {
	return `${Date.now()}_${Math.random().toString(36).slice(2, 8)}`
}

function clearTimers() {
	if (typingTimer) {
		clearInterval(typingTimer)
		typingTimer = null
	}
	if (recTimer) {
		clearInterval(recTimer)
		recTimer = null
	}
}

Page({
	data: {
		messages: [],
		inputText: '',
		scrollIntoView: '',
		streaming: false,
		recording: false,
		cancelHint: false,
		recTime: '0:00',
		confirmVisible: false,
		confirmText: '',
		recognizing: false,
		showHints: true,
		hints: HINTS,
		storeName: '高新店',
	},

	onLoad() {
		bindRecorder()
		this._recorderOn = false
		this._ignoreRecord = true
		this.seedWelcome()
	},

	onUnload() {
		clearTimers()
	},

	seedWelcome() {
		const welcome = {
			id: uid(),
			role: 'agent',
			text: '你好，我是经营助手。今天想问点什么？比如："今天营业额多少？"（当前为本地演示数据）',
			meta: `经营助手 · ${timeStr()}`,
		}
		this.setData({
			messages: [welcome]
		}, () => this.scrollBottom())
	},

	scrollBottom() {
		this.setData({
			scrollIntoView: ''
		}, () => {
			this.setData({
				scrollIntoView: 'msg-bottom'
			})
		})
	},

	updateMessage(id, patch) {
		const messages = this.data.messages.map((m) =>
			m.id === id ? Object.assign({}, m, patch) : m
		)
		this.setData({
			messages
		})
	},

	onInput(e) {
		this.setData({
			inputText: e.detail.value
		})
	},

	onHintTap(e) {
		const text = e.currentTarget.dataset.text
		this.setData({
			inputText: text,
			showHints: false
		})
		this.send(text)
	},

	onSend() {
		this.send(this.data.inputText)
	},

	onStop() {
		stopped = true
	},

	send(raw) {
		const q = (raw || '').trim()
		if (!q || this.data.streaming || this.data.recording) return

		const userMsg = {
			id: uid(),
			role: 'user',
			text: q,
			meta: timeStr(),
		}

		this.setData({
				messages: this.data.messages.concat([userMsg]),
				inputText: '',
				showHints: false,
				confirmVisible: false,
			},
			() => {
				this.scrollBottom()
				setTimeout(() => this.streamMock(mockReply(q)), 400)
			}
		)
	},

	streamMock(reply) {
		const id = uid()
		const holder = {
			id,
			role: 'agent',
			text: '',
			meta: `经营助手 · ${timeStr()}`,
			typing: true,
		}

		stopped = false
		this.setData({
				messages: this.data.messages.concat([holder]),
				streaming: true,
			},
			() => this.scrollBottom()
		)

		let i = 0
		const full = reply.text
		if (typingTimer) clearInterval(typingTimer)

		typingTimer = setInterval(() => {
			if (stopped) {
				clearInterval(typingTimer)
				typingTimer = null
				const current = this.data.messages.find((m) => m.id === id)
				this.updateMessage(id, {
					typing: false,
					showCaret: false,
					stopped: true,
					text: ((current && current.text) || '').replace(/\s+$/, '') || full.slice(0, Math.max(i, 2)),
				})
				this.setData({
					streaming: false
				})
				this.scrollBottom()
				return
			}

			i += 2
			this.updateMessage(id, {
				typing: false,
				showCaret: i < full.length,
				text: full.slice(0, i),
			})
			this.scrollBottom()

			if (i >= full.length) {
				clearInterval(typingTimer)
				typingTimer = null
				this.updateMessage(id, {
					typing: false,
					showCaret: false,
					text: full,
					card: reply.card,
				})
				this.setData({
					streaming: false
				})
				this.scrollBottom()
			}
		}, 24)
	},

	onVoiceStart(e) {
		if (this.data.streaming || this.data.recognizing) return
		const touch = e.touches[0]
		touchStartY = touch ? touch.clientY : 0
		recStart = Date.now()
		recordToken += 1
		this._recordToken = recordToken
		this._ignoreRecord = false
		this.setData({
			recording: true,
			cancelHint: false,
			recTime: '0:00',
			confirmVisible: false,
			confirmText: '',
		})

		if (recTimer) clearInterval(recTimer)
		recTimer = setInterval(() => {
			const s = Math.floor((Date.now() - recStart) / 1000)
			this.setData({
				recTime: `0:${pad2(s)}`
			})
		}, 200)

		try {
			recorder.start({
				duration: 60000,
				sampleRate: 16000,
				numberOfChannels: 1,
				encodeBitRate: 48000,
				format: 'mp3',
			})
			this._recorderOn = true
		} catch (err) {
			this._recorderOn = false
			this._ignoreRecord = true
			this.setData({
				recording: false
			})
			wx.showToast({
				title: '无法开始录音',
				icon: 'none'
			})
		}
	},

	onVoiceMove(e) {
		if (!this.data.recording) return
		const touch = e.touches[0]
		if (!touch) return
		const dy = touchStartY - touch.clientY
		const cancelHint = dy > 60
		if (cancelHint !== this.data.cancelHint) {
			this.setData({
				cancelHint
			})
		}
	},

	onVoiceCancel() {
		this.finishVoice(true)
	},

	onVoiceEnd() {
		this.finishVoice(this.data.cancelHint)
	},

	finishVoice(cancelled) {
		if (!this.data.recording) return
		if (recTimer) {
			clearInterval(recTimer)
			recTimer = null
		}
		const dur = Math.round((Date.now() - recStart) / 1000)
		const tooShort = !cancelled && dur < 1
		this._ignoreRecord = cancelled || tooShort
		this._pendingToken = this._ignoreRecord ? 0 : this._recordToken
		this.setData({
			recording: false,
			cancelHint: false
		})

		if (this._recorderOn) {
			this._recorderOn = false
			try {
				recorder.stop()
			} catch (err) {
				// ignore
			}
		}

		if (cancelled) return
		if (tooShort) {
			wx.showToast({
				title: '录音太短，请重说',
				icon: 'none'
			})
		}
	},

	handleRecordStop(res) {
		if (this._ignoreRecord || !this._pendingToken || this._pendingToken !== this._recordToken) return
		this._pendingToken = 0
		if (!(res && res.tempFilePath)) {
			wx.showToast({
				title: '没有录到声音',
				icon: 'none'
			})
			return
		}
		// 演示阶段不接语音识别，后续接后端接口
		wx.showToast({
			title: '演示模式暂不支持语音',
			icon: 'none'
		})
	},

	handleRecordError(err) {
		this._recorderOn = false
		this._ignoreRecord = true
		if (recTimer) {
			clearInterval(recTimer)
			recTimer = null
		}
		this.setData({
			recording: false,
			recognizing: false
		})
		const msg = (err && err.errMsg) || ''
		if (/auth|deny|permission/i.test(msg)) {
			wx.showModal({
				title: '需要麦克风权限',
				content: '请在设置中允许使用麦克风，再按住说话。',
				confirmText: '去设置',
				success(res) {
					if (res.confirm) wx.openSetting()
				},
			})
			return
		}
		if (this.data.recording || /start/i.test(msg)) {
			wx.showToast({
				title: '录音失败，请重试',
				icon: 'none'
			})
		}
	},

	onConfirmInput(e) {
		this.setData({
			confirmText: e.detail.value
		})
	},

	onCancelConfirm() {
		this.setData({
			confirmVisible: false,
			confirmText: ''
		})
	},

	onOkConfirm() {
		const t = this.data.confirmText.trim()
		this.setData({
			confirmVisible: false,
			confirmText: ''
		})
		if (t) this.send(t)
	},
})