/** @format */

import {cBody} from './Body'
import {Line, RVOMath, Vector2} from './Maths'

export class ObserverObj<T> {
    public value: T

    constructor(val?: T) {
        if (val) this.value = val
    }
}

export class KeyValuePair<K, V> {
    public Key: K
    public Value: V

    constructor(key: K, value: V) {
        this.Key = key
        this.Value = value
    }
}

export class RVOConfig {
    /**代理对象总数 */
    public static agentCount = 10
    /**代理对象之间的距离 */
    public static neighborDist = 0.75 //25;
    /**代理对象的半径 */
    public static radius = 0.5 //10;
    /**代理对象的最大移动速度 */
    public static maxSpeed = 1
    /**代理对象的初始速度 */
    public static velocity: cc.Vec3 = new cc.Vec3()
    /**最大邻居数 */
    public static maxNeighbors = 10

    /**安全单位时间，值越大，就会越早做出避让行为 */
    public static timeHorizon = 5 //25;

    /**与timeHorizon类似，只针对障碍物 */
    public static timeHorizonObst = 0

    /**步骤帧 */
    public static timeStep = 0.05 //0.25
}

export class Agent {
    private static _inst: Agent = null
    static get inst() {
        if (this._inst == null) {
            this._inst = new Agent()
        }
        return this._inst
    }

    check(a: cBody, b: cBody) {
        let invTimeHorizon = 1.0 / RVOConfig.timeHorizon
        let relativePosition = Vector2.subtract(b.getCenter(), a.getCenter())
        let relativeVelocity = Vector2.subtract(a.newVelocity, b.newVelocity)
        let combinedRadius = a.neighborDist + b.neighborDist
        let combinedRadiusSq = RVOMath.sqr(combinedRadius)
        let distSq = RVOMath.absSq(relativePosition)

        let u = new Vector2()
        let direction = new Vector2()

        if (distSq > combinedRadiusSq) {
            let w = Vector2.subtract(relativeVelocity, Vector2.multiply2(invTimeHorizon, relativePosition))
            let wLengthSq = RVOMath.absSq(w)
            let dotProduct1 = Vector2.multiply(w, relativePosition)

            if (dotProduct1 < 0 && RVOMath.sqr(dotProduct1) > combinedRadiusSq * wLengthSq) {
                let wLength = RVOMath.sqrt(wLengthSq)
                let unitW = Vector2.division(w, wLength)
                direction = new Vector2(unitW.y, -unitW.x)
                u = Vector2.multiply2(combinedRadius * invTimeHorizon - wLength, unitW)
            } else {
                let leg = RVOMath.sqrt(distSq - combinedRadiusSq)
                if (RVOMath.det(relativePosition, w) > 0) {
                    direction = Vector2.division(
                        new Vector2(
                            relativePosition.x * leg - relativePosition.y * combinedRadius,
                            relativePosition.x * combinedRadius + relativePosition.y * leg,
                        ),
                        distSq,
                    )
                } else {
                    direction = Vector2.division(
                        new Vector2(
                            relativePosition.x * leg + relativePosition.y * combinedRadius,
                            -relativePosition.x * combinedRadius + relativePosition.y * leg,
                        ),
                        -distSq,
                    )
                }

                let dotProduct2 = Vector2.multiply(relativeVelocity, direction)
                u = Vector2.subtract(Vector2.multiply2(dotProduct2, direction), relativeVelocity)
            }
        } else {
            let invTimeStep = 1.0 / RVOConfig.timeStep
            let w = Vector2.subtract(relativeVelocity, Vector2.multiply2(invTimeStep, relativePosition))
            let wLength = RVOMath.abs(w)
            let unitW = Vector2.division(w, wLength)

            direction = new Vector2(unitW.y, -unitW.x)
            u = Vector2.multiply2(combinedRadius * invTimeStep - wLength, unitW)
        }

        let lineA = new Line()
        lineA.direction = new Vector2(direction.x, direction.y)
        lineA.point = Vector2.addition(a.newVelocity, Vector2.multiply2(0.5, u))
        a.orcaLines.push(lineA)
    }

    process(bodys: Array<cBody>) {
        for (let i = 0, j = bodys.length; i < j; i++) {
            let body = bodys[i]
            if (body.isAgent && body.orcaLines.length > 0) {
                if (!body.isRemove && body.object) {
                    let numObstLines = 0 //默认0wh
                    let tempVelocity_ = new ObserverObj<Vector2>(new Vector2(body.newVelocity.x, body.newVelocity.y))
                    let lineFail = this.linearProgram2(
                        body.orcaLines,
                        body.maxVelocity,
                        body.prefVelocity,
                        false,
                        tempVelocity_,
                    )
                    if (lineFail < body.orcaLines.length) {
                        this.linearProgram3(body.orcaLines, numObstLines, lineFail, body.maxVelocity, tempVelocity_)
                    }

                    let value = tempVelocity_.value
                    body.prefVelocity.x = body.newVelocity.x
                    body.prefVelocity.y = body.newVelocity.y
                    // body.newVelocity.x = value.x;
                    // body.newVelocity.y = value.y;

                    if (body.object) {
                        let v = body.object.velocity
                        v.x = value.x
                        v.y = value.y
                        v.z = 0
                    }
                }
                body.orcaLines.length = 0
            }
        }
    }

    private linearProgram1(
        lines: Array<Line>,
        lineNo: number,
        radius: number,
        optVelocity: Vector2,
        directionOpt: boolean,
        result: ObserverObj<Vector2>,
    ): boolean {
        let dotProduct = Vector2.multiply(lines[lineNo].point, lines[lineNo].direction)
        let discriminant = RVOMath.sqr(dotProduct) + RVOMath.sqr(radius) - RVOMath.absSq(lines[lineNo].point)

        if (discriminant < 0) {
            return false
        }

        let sqrtDiscriminant = RVOMath.sqrt(discriminant)
        let tLeft = -dotProduct - sqrtDiscriminant
        let tRight = -dotProduct + sqrtDiscriminant

        for (let i = 0; i < lineNo; ++i) {
            let denominator = RVOMath.det(lines[lineNo].direction, lines[i].direction)
            let numerator = RVOMath.det(lines[i].direction, Vector2.subtract(lines[lineNo].point, lines[i].point))

            if (RVOMath.fabs(denominator) <= RVOMath.RVO_EPSILON) {
                if (numerator < 0) {
                    return false
                }
                continue
            }

            let t = numerator / denominator

            if (denominator > 0) {
                tRight = Math.min(tRight, t)
            } else {
                tLeft = Math.max(tLeft, t)
            }

            if (tLeft > tRight) {
                return false
            }
        }

        if (directionOpt) {
            if (Vector2.multiply(optVelocity, lines[lineNo].direction) > 0) {
                result.value = Vector2.addition(lines[lineNo].point, Vector2.multiply2(tRight, lines[lineNo].direction))
            } else {
                result.value = Vector2.addition(lines[lineNo].point, Vector2.multiply2(tLeft, lines[lineNo].direction))
            }
        } else {
            let t = Vector2.multiply(lines[lineNo].direction, Vector2.subtract(optVelocity, lines[lineNo].point))
            if (t < tLeft) {
                result.value = Vector2.addition(lines[lineNo].point, Vector2.multiply2(tLeft, lines[lineNo].direction))
            } else if (t > tRight) {
                result.value = Vector2.addition(lines[lineNo].point, Vector2.multiply2(tRight, lines[lineNo].direction))
            } else {
                result.value = Vector2.addition(lines[lineNo].point, Vector2.multiply2(t, lines[lineNo].direction))
            }
        }

        return true
    }

    private linearProgram2(
        lines: Array<Line>,
        radius: number,
        optVelocity: Vector2,
        directionOpt: boolean,
        result: ObserverObj<Vector2>,
    ): number {
        if (directionOpt) {
            result.value = Vector2.multiply2(radius, optVelocity)
        } else if (RVOMath.absSq(optVelocity) > RVOMath.sqr(radius)) {
            result.value = Vector2.multiply2(radius, RVOMath.normalize(optVelocity))
        } else {
            result.value = optVelocity
        }

        for (let i = 0; i < lines.length; ++i) {
            if (RVOMath.det(lines[i].direction, Vector2.subtract(lines[i].point, result.value)) > 0) {
                let tempResult = new Vector2(result.value.x, result.value.y)
                if (!this.linearProgram1(lines, i, radius, optVelocity, directionOpt, result)) {
                    result.value = tempResult
                    return i
                }
            }
        }

        return lines.length
    }

    private linearProgram3(
        lines: Array<Line>,
        numObstLines: number,
        beginLine: number,
        radius: number,
        result: ObserverObj<Vector2>,
    ) {
        let distance = 0
        for (let i = beginLine; i < lines.length; ++i) {
            if (RVOMath.det(lines[i].direction, Vector2.subtract(lines[i].point, result.value)) > distance) {
                let projLines: Array<Line> = []
                for (let ii = 0; ii < numObstLines; ++ii) {
                    projLines[projLines.length] = lines[ii]
                }

                for (let j = numObstLines; j < i; ++j) {
                    let line = new Line()
                    let determinant = RVOMath.det(lines[i].direction, lines[j].direction)
                    if (RVOMath.fabs(determinant) <= RVOMath.RVO_EPSILON) {
                        if (Vector2.multiply(lines[i].direction, lines[j].direction) > 0.0) {
                            continue
                        } else {
                            line.point = Vector2.multiply2(0.5, Vector2.addition(lines[i].point, lines[j].point))
                        }
                    } else {
                        line.point = Vector2.addition(
                            lines[i].point,
                            Vector2.multiply2(
                                RVOMath.det(lines[j].direction, Vector2.subtract(lines[i].point, lines[j].point)) /
                                    determinant,
                                lines[i].direction,
                            ),
                        )
                    }

                    let d = Vector2.subtract(lines[j].direction, lines[i].direction)
                    if (RVOMath.absSq(d) > 0) {
                        line.direction = RVOMath.normalize(d)
                        projLines[projLines.length] = line
                    }
                }

                let tempResult = new Vector2(result.value.x, result.value.y)
                if (
                    this.linearProgram2(
                        projLines,
                        radius,
                        new Vector2(-lines[i].direction.y, lines[i].direction.x),
                        true,
                        result,
                    ) < projLines.length
                ) {
                    result.value = tempResult
                }
                distance = RVOMath.det(lines[i].direction, Vector2.subtract(lines[i].point, result.value))
            }
        }
    }
}