import { board } from "../board.js"
import { Vector2 } from "../engine/vector2.js"

const SURROUNDING = [
    new Vector2(-1, 0),
    new Vector2(0, 1),
    new Vector2(0, -1),
    new Vector2(1, 0),
]

export function hasLiberties({
    position,
    team
}) {
    if (getPiece(position) != undefined) return false
    let groups = getSurroundingGroups(position, team)
    // if (stones.length > 0) console.log(stones)
    // console.log(stones)
    return true
    // return checkLiberties({
    //     position,
    //     team
    // })
}

function getSurroundingGroups(position, team) {
    return getSurroundingSquares(position)
        .filter(p => getPiece(p) != undefined)
        .filter(p => getPiece(p).team == team)
        .map(p => getGroup({position: p}))
}

function getGroup({position, checkedPositions = []}) {
    if (isInArray(position, checkedPositions)) {
        return
    }

    checkedPositions.push(position)
    let team = getPiece(position).team

    getSurroundingSquares(position)
        .filter(p => getPiece(p) != undefined)
        .filter(p => getPiece(p).team == team)
        .forEach(p => {
            getGroup({
                position: p,
                checkedPositions: checkedPositions
            })
        })

    return checkedPositions
}

function getPiece(position) {
    return board.stones[position.y][position.x]
}

function checkLiberties({
    position,
    team,
    checkedStones = [],
    checkedLiberties = [],
    checkedEnemies = [],
    isAttacking = false,
    isRoot = true,
}) {
    if (isInArray(position, checkedStones)) {
        return
    }

    checkedStones.push(position)

    let surroundingSquares = getSurroundingSquares(position)

    surroundingSquares.every((z) => {
        let s = board.stones[z.y][z.x]
        switch (true) {
            case s == undefined:
                pushIfNotInArray(z, checkedLiberties)
                break

            case s.team == team:
                handleFriendlyStone({
                    position: z,
                    team: team,
                    checkedStones: checkedStones,
                    checkedLiberties: checkedLiberties,
                    checkedEnemies: checkedEnemies,
                    isAttacking: isAttacking,
                })
                break

            case s.team != team:
                if (isAttackingEnemyStone({
                    position: z,
                    team: s.team,
                    checkedEnemies: checkedEnemies,
                    isAttacking: isAttacking,
                })) {
                    isAttacking = true
                    return false
                }
                break
        }

        return true
    })

    if (isRoot) {
        let liberties = checkedLiberties
            .filter(x => !Vector2.equals(x, position))
            .length

        if (liberties > 0 || isAttacking) {
            return true
        }

        return false
    }
}

function isInArray(position, array) {
    return Array.from(array)
        .some(p => Vector2.equals(p, position))
}

function pushIfNotInArray(position, array) {
    if (!isInArray(position, array)) {
        array.push(position)
    }
}

function getSurroundingSquares(position) {
    return Array.from(SURROUNDING)
        .map(v => Vector2.sum(v, position))
        .filter(z => 0 <= z.x && z.x < board.size &&
            0 <= z.y && z.y < board.size
        )
}

function handleFriendlyStone(data) {
    checkLiberties({
        position: data.position,
        team: data.team,
        checkedStones: data.checkedStones,
        checkedLiberties: data.checkedLiberties,
        checkedEnemies: data.checkedEnemies,
        isAttacking: data.isAttacking,
        isRoot: false,
    })
}

function isAttackingEnemyStone({
    position,
    isAttacking,
    checkedEnemies,
}) {
    if (isAttacking) {
        return
    }

    let liberties = getEnemyLiberties({
        position: position,
        team: board.stones[position.y][position.x].team,
        checkedEnemies: checkedEnemies,
    })

    if (liberties == 1) {
        return true
    }

    return false
}

function getEnemyLiberties({
    position,
    team,
    checkedEnemies,
    checkedEnemyLiberties = [],
}) {
    if (isInArray(position, checkedEnemies)) {
        return
    }

    checkedEnemies.push(position)

    getSurroundingSquares(position)
        .forEach(z => {
            let s = board.stones[z.y][z.x]
            switch (true) {
                case s == undefined:
                    pushIfNotInArray(z, checkedEnemyLiberties)
                    break
                case s.team == team:
                    getEnemyLiberties({
                        position: z,
                        team: team,
                        checkedEnemies: checkedEnemies,
                        checkedEnemyLiberties: checkedEnemyLiberties,
                    })
                    break
            }
        })

    return checkedEnemyLiberties.length
}