import Events from '../events.js'
import { Angle } from '../utils.js'

class StylusCommand extends Object {

    constructor() {
        super()
    }

    do(stylus) {
        stylus.commandStack.push(this)
    }

    undo(stylus) {
        stylus.undoCommandStack.push(this)
    }

    redo(stylus) {
        this.do(stylus)
    }
}

class StrokeCommand extends StylusCommand {

    constructor(stroke) {
        super()
        this.stroke = stroke
    }

    do(stylus) {
        if (this.stroke.length > 0) {
            super.do(stylus)
            stylus.stroke = []
            stylus.strokes.push(this.stroke)
            stylus.redraw()
            stylus.changed()
        }
    }

    undo(stylus) {
        if (this.stroke.length > 0) {
            super.undo(stylus)
            stylus.strokes.pop()
            stylus.redraw()
            stylus.changed()
        }
    }
}

class ClearCommand extends StylusCommand {

    do(stylus) {
        // Clears the command stack
        stylus.commandStack = []
        super.do(stylus)
        this.strokes = stylus.strokes
        stylus.stroke = []
        stylus.strokes = []
        stylus.redraw()
        stylus.changed()
    }

    undo(stylus) {
        //super.undo(stylus) // Clear all is not redoable
        stylus.stroke = []
        stylus.strokes = this.strokes
        stylus.redraw()
        stylus.changed()
    }
}


export default class Stylus extends PIXI.Graphics {

    constructor({ width = window.innerWidth,
        height = window.innerHeight,
        interactive = true,
        color = 0x000000,
        tiltX = 0,
        tiltY = 0,
        backgroundAlpha = 1,
        backgroundFill = 0xFFFFFF,
        colorAlpha = 1,
        captureEvents = true,
        acceptMouseEvents = true } = {}) {
        super()
        this.wantedWidth = width
        this.wantedHeight = height
        this.backgroundAlpha = backgroundAlpha
        this.backgroundFill = backgroundFill
        this.colorAlpha = colorAlpha
        this.color = color
        this.interactive = interactive
        this.debug = false
        this.tiltX = tiltX  // degrees -90 ... 90
        this.tiltY = tiltY  // degrees -90 ... 90
        this.captureEvents = captureEvents
        this.commandStack = []
        this.undoCommandStack = []
        this.strokes = []
        this.stroke = []
        if (captureEvents)
            this.registerEventHandler(acceptMouseEvents)
        this.drawBackground()
    }

    drawBackground() {
        this.clear()
        this.beginFill(this.backgroundFill, this.backgroundAlpha)
        this.drawRect(0, 0, this.wantedWidth, this.wantedHeight)
        this.endFill()
    }

    touchToPoint(t) {
        return { x: t.clientX, y: t.clientY }
    }

    isStylusPointer(event) {
        let identifier = event.data.identifier
        if (typeof (event.data.originalEvent.changedTouches) !== 'undefined') {
            for (let touch of event.data.originalEvent.changedTouches) {
                if (touch.identifier === identifier && touch.touchType === 'stylus') {
                    this.tiltX = Angle.radian2degree(touch.azimuthAngle)
                    this.tiltY = 90.0 - Angle.radian2degree(touch.altitudeAngle)
                    return true
                }
            }
        }
        // UO: Not tested since the Sprot delivered "mouse" events to Chrome
        if (event.data.originalEvent.pointerType === 'pen') {
            this.tiltX = event.data.originalEvent.tiltX
            this.tiltY = event.data.originalEvent.tiltY
            return true
        }
        return false
    }

    isStylusTouch(event) {
        let identifier = event.data.identifier
        if (typeof (event.data.originalEvent.changedTouches) !== 'undefined') {
            for (let touch of event.data.originalEvent.changedTouches) {
                if (touch.identifier === identifier && touch.pointerType === 'touch') {
                    return true
                }
            }
        }
        return false
    }

    getPointerID(event) {
        let identifier = event.data.identifier
        for (let touch of event.data.originalEvent.changedTouches) {
            if (touch.identifier === identifier) {
                return touch.pointerId
            }
        }
    }

    registerEventHandler() {
        window.addEventListener('keydown', (e) => {
            switch (e.keyCode) {
                case 38:  // up arrow
                    this.tiltX += 5
                    break
                case 40:  // down arrow
                    this.tiltX -= 5
                    break
                case 37:  // left arrow
                    this.tiltY -= 5
                    break
                case 39:  // right arrow
                    this.tiltY += 5
                    break
            }
            if (this.debug) console.log("keydown", e.keyCode, this.tiltX, this.tiltY)
        })

        this.on('pointerdown', (e) => {
            if (this.debug) console.log("pointerdown", e)
            if (this.eventInside(e))
                this.startStroke(this.toStroke(e))
        })
        this.on('pointermove', (e) => {
            if (Events.isPointerDown(e.data.originalEvent) || this.isStylusPointer(e) || this.isStylusTouch(e)) {
                if (this.debug) console.log("pointermove", e, this.eventInside(e))
                if (this.eventInside(e))
                    this.moveStroke(this.toStroke(e))
            }
        })
        this.on('pointerup', (e) => {
            if (this.debug) console.log("pointerup", e)
            if (this.eventInside(e))
                this.endStroke(this.toStroke(e))
        })
        this.on('pointerleave', (e) => {
            this.endStroke(this.toStroke(e))
        })
        this.on('pointercancel', (e) => {
            this.endStroke(this.toStroke(e))
        })
    }

    undoable() {
        return this.commandStack.length > 0
    }

    redoable() {
        return this.undoCommandStack.length > 0
    }

    undo() {
        if (this.undoable()) {
            let cmd = this.commandStack.pop()
            cmd.undo(this)
        }
    }

    redo() {
        if (this.redoable()) {
            let cmd = this.undoCommandStack.pop()
            cmd.redo(this)
        }
    }

    eventInside(event) {

        let local = this.toLocal(event.data.global)
        for (let child of this.children) {
            let r = child.getBounds()
            if (r.contains(local.x, local.y)) {
                console.log("Child touched")
                return false
            }
        }
        if (local.x < 0 || local.x > this.wantedWidth)
            return false
        if (local.y < 0 || local.y > this.wantedHeight)
            return false
        event.stopPropagation()
        if (this.debug) console.log("stopPropagation", event)
        if (event.data.originalEvent.claimedByScatter) {
            return false
        }
        return true
    }

    toLocalPoint(event) {
        return this.toLocal(event.data.global)
    }

    toStroke(event) {
        let local = this.toLocalPoint(event)
        let x = Math.max(0, Math.min(local.x, this.wantedWidth))
        let y = Math.max(0, Math.min(local.y, this.wantedHeight))
        let desc = {
            x, y,
            pressure: event.pressure || null,
            tiltX: this.tiltX, tiltY: this.tiltY,
            color: this.color
        }
        return desc
    }

    startStroke(info) {
        this.stroke = [info]
        this.redraw()
    }

    moveStroke(info) {
        this.stroke.push(info)
        this.redraw()
    }

    endStroke(info) {
        if (this.stroke.length > 1) {
            let cmd = new StrokeCommand(this.stroke)
            cmd.do(this)
        }
    }

    tiltToLineWidth(value) {
        return Math.round(Math.abs(value / 10) + 1)
    }

    drawStroke(stroke) {
        if (stroke.length) {
            let start = stroke[0]
            this.beginFill(0, 0)
            this.moveTo(start.x, start.y)
            for (let i = 1; i < stroke.length; i++) {
                let info = stroke[i]
                this.lineStyle(this.tiltToLineWidth(info.tiltY),
                    info.color, this.colorAlpha)
                this.lineTo(info.x, info.y)
            }
            this.endFill()
        }
    }

    drawTouch(point) {
        this.beginFill(0, 0)
        this.drawCircle(point.x, point.y, 22)
        this.endFill()
    }

    drawStrokes() {
        this.drawBackground()
        this.lineStyle(1.0, 0xFF0000, 1)
        for (let stroke of this.iterStrokes()) {
            this.drawStroke(stroke)
        }
    }

    redraw() {
        this.drawStrokes()
    }

    // Can be overwritten if different levels of strokes are necessary
    *iterStrokes() {
        for (let stroke of this.strokes) {
            yield stroke
        }
        yield this.stroke
    }

    changed() {
        // Can be overwritten
    }

    clearAll() {
        let cmd = new ClearCommand()
        cmd.do(this)
    }

    normalizeInfo(info) {
        let { x, y, pressure, tiltX, tiltY, color } = info
        x /= this.wantedWidth
        y /= this.wantedHeight
        return { x, y, pressure, tiltX, tiltY, color }
    }

    denormalizeInfo(info) {
        let { x, y, pressure, tiltX, tiltY, color } = info
        x = x * this.wantedWidth
        y = y * this.wantedHeight
        return { x, y, pressure, tiltX, tiltY, color }
    }

    // Convert strokes into an object that can be stored in an Indexed DB.
    // Returns normalized strokes
    toObject() {
        let result = []
        for (let stroke of this.strokes) {
            let normalized = []
            for (let info of stroke) {
                normalized.push(this.normalizeInfo(info))
            }
            result.push(normalized)
        }
        return result
    }

    // Read normalized strokes from an object from an Indexed DB.
    fromObject(normalizedStrokes) {
        this.strokes = []
        for (let stroke of normalizedStrokes) {
            let denormalized = []
            for (let info of stroke) {
                denormalized.push(this.denormalizeInfo(info))
            }
            this.strokes.push(denormalized)
        }
    }

    // Convert strokes into a JSON object that can be stored in an Indexed DB
    toJSON() {
        return JSON.stringify(this.toObject())
    }

    // Convert strokes from a JSON
    fromJSON(json) {
        this.fromObject(JSON.parse(json))
    }

    // Returns a set of used colors
    usedColors() {
        let used = new Set()
        for (let info of this.stroke) {
            used.add(info.color)
        }
        for (let stroke of this.strokes) {
            for (let info of stroke) {
                used.add(info.color)
            }
        }
        return used.values()
    }
}