import { getMap } from "../map.js";
import { Map, Vec2, GhostType, GameState, SpawnIndex, Player, Rotation, GhostState, Tile, Ghost } from "../types.js";
import { random } from "./logic.js";
import { MOVE_SPEED, roundPos, isStablePos, getTile, getTileFrontWithRot, incrementPos, wrapPos } from "./movement.js";

const vec2eq = (a: Vec2, b: Vec2): boolean => {
    return a.x == b.x && a.y == b.y
}

const canPath = (tile: Tile): boolean => tile != Tile.WALL
const canCollide = (tile: Tile, isPathing: boolean): boolean => tile != Tile.WALL && (isPathing ? true : tile != Tile.GHOST_EXIT)

const path = (start: Vec2, end: Vec2, map: Map) => {
    let mask: Vec2[] = new Array(map.width * map.height)
    let queue: Vec2[] = []
    queue.push(start)

    while (true) {

        let next: Vec2 = queue.shift()
        if (!next) {
            console.log('failed')
            return undefined
        }
        if (vec2eq(next, end)) break

        let north = canPath(getTile(map, next, 0, -1))
        let south = canPath(getTile(map, next, 0, 1))
        let east = canPath(getTile(map, next, 1, 0))
        let west = canPath(getTile(map, next, -1, 0))
    
        if (north && !mask[(next.y - 1) * map.width + (next.x)]) {
            queue.push({x: next.x, y: next.y - 1})
            mask[(next.y - 1) * map.width + (next.x)] = next
        }
        
        if (south && !mask[(next.y + 1) * map.width + (next.x)]) {
            queue.push({x: next.x, y: next.y + 1})
            mask[(next.y + 1) * map.width + (next.x)] = next
        }
        
        if (east && !mask[(next.y) * map.width + (next.x + 1)]) {
            queue.push({x: next.x + 1, y: next.y})
            mask[(next.y) * map.width + (next.x + 1)] = next
        }
        
        if (west && !mask[(next.y) * map.width + (next.x - 1)]) {
            queue.push({x: next.x - 1, y: next.y})
            mask[(next.y) * map.width + (next.x - 1)] = next
        }
    }

    let solution = []

    let next = end
    while (true) {
        solution.push(structuredClone(next))
        if (vec2eq(next, start)) {
            break
        } else {
            next = mask[next.y * map.width + next.x]
        }
    }

    solution = solution.reverse()
    solution.shift()

    return solution

}

const diff = (a: Vec2, b:Vec2): Vec2 => {
    return {x: a.x - b.x, y: a.y - b.y}
}

const dist = (a: Vec2, b: Vec2): number => {
    return Math.sqrt(Math.pow(a.x - b.x, 2) + Math.pow(a.y - b.y, 2)) 
}

const trans = (pos: Vec2, rot: Rotation, dist: number): Vec2 => {
    switch (rot) {
        case Rotation.NORTH:
        case Rotation.NOTHING:
            return {x: pos.x - dist, y: pos.y - dist}
        case Rotation.EAST:
            return {x: pos.x + dist, y: pos.y}
        case Rotation.SOUTH:
            return {x: pos.x, y: pos.y + dist}
        case Rotation.WEST:
            return {x: pos.x - dist, y: pos.y}
    }
}

const getNearestPlayer = (state: GameState, pos: Vec2): Player => {
    let min = undefined;
    let nearest = undefined;
    for (let id in state.players) {
        let player = state.players[id];

        if (!player || player.dead) {
            continue
        }

        let d = dist(player.pos, pos)
        if (!min || min > d) {
            min = d
            nearest = player
        }
    }

    return nearest
}

const pickTargetScatter = (state: GameState, type: GhostType): Vec2 => {
    let map = getMap(state.mapId)
    switch (type) {
        case GhostType.BLINKY:
            return {x: 0, y: -1}
        case GhostType.PINKY:
            return {x: map.width - 1, y: -1}
        case GhostType.INKY:
            return {x: map.width - 1, y: map.height}
        case GhostType.CLYDE:
            return {x: 0, y: map.height}
    }   
}

const pickTargetChase = (state: GameState, type: GhostType): Vec2 => {
    let ghost = state.ghosts[type]
    let player = getNearestPlayer(state, ghost.pos)
    switch (type) {
        case GhostType.BLINKY:
            return {x: player.pos.x, y: player.pos.y}
        case GhostType.PINKY:
            return trans(player.pos, player.moveRotation, 2)
        case GhostType.INKY:
            let target = trans(player.pos, player.moveRotation, 1)
            let vec = diff(target, state.ghosts[GhostType.BLINKY].pos)
            return {x: target.x + vec.x, y: target.y + vec.y}
        case GhostType.CLYDE:
            if (dist(ghost.pos, player.pos) > 8)
                return {x: player.pos.x, y: player.pos.y}
            else
                return pickTargetScatter(state, type)
    } 
}



const pickTarget = (state: GameState, map: Map, type: GhostType): Vec2 => {
    let ghost: Ghost = state.ghosts[type]

    let target = ghost.targetQueue.shift()
    if (target) {
        return target
    }

    switch (ghost.state) {
        case GhostState.SCATTER:
            return pickTargetScatter(state, type)
        case GhostState.CHASE:
            return pickTargetChase(state, type)
        case GhostState.EATEN:
            return structuredClone(map.spawns[SpawnIndex.GHOST_SPAWN])
        case GhostState.SCARED:
            return {
                x: random(state) % map.width,
                y: random(state) % map.height
            }
    }
}

const checkIfEaten = (ghost: Ghost, state: GameState): boolean => {

    if (ghost.state != GhostState.SCARED) {
        return false
    }

    for (let id in state.players) {
        let player = state.players[id]

        if (!player || player.dead) {
            continue
        }

        if (player.thiccLeft > 0 && dist(player.pos, ghost.pos) <= 1) {
            return true
        }
    }

    return false
}

const updateKilled = (ghost: Ghost, state: GameState) => {
   
    if (ghost.state == GhostState.EATEN) {
        return
    }

    for (let id in state.players) {
        let player = state.players[id]

        if (!player || player.dead) {
            continue
        }

        if (dist(player.pos, ghost.pos) > 1) {
            continue
        }

        if (ghost.state != GhostState.SCARED || player.thiccLeft < 1) {
            player.dead = true
            player.framesDead = 0
        } 
    }

}

const getGhostState = (ghost: Ghost, state: GameState): GhostState => {

    if (ghost.state == GhostState.EATEN || checkIfEaten(ghost, state)) {
        ghost.hasRespawned = false
        return GhostState.EATEN
    }

    if (Object.values(state.players).filter((p: Player) => p.thiccLeft > 0).length > 0) {
        if (!ghost.hasRespawned) {
            return GhostState.SCARED
        }
    } else {
        ghost.hasRespawned = false
    }

    return (Object.keys(state.items).length % 100 < 10 ? GhostState.SCATTER : GhostState.CHASE)
}

const getGhostPath = (ghost: Ghost, map: Map): Vec2[] => {

    if (ghost.targetQueue.length > 0) { // already pathing
        return undefined
    }

    if (ghost.state == GhostState.EATEN) { // dead go back to spawn
        if (vec2eq(ghost.pos, map.spawns[SpawnIndex.GHOST_SPAWN])) { // returned to spawn, exit the box
            ghost.state = GhostState.CHASE
            ghost.hasRespawned = true
            return path(ghost.pos, map.spawns[SpawnIndex.GHOST_EXIT], map)
        } else { // go to the box still dead
            return path(ghost.pos, map.spawns[SpawnIndex.GHOST_SPAWN], map)
        }
    }

    let tile = getTile(map, ghost.pos, 0, 0)
    if (tile != Tile.GHOST_WALL && tile != Tile.GHOST_SPAWN) { // not in the box
        return undefined
    }

    let threshold = 0
    switch (ghost.type) {
        case GhostType.BLINKY:
            threshold = 60 * 5
            break
        case GhostType.PINKY:
            threshold = 60 * 10
            break
        case GhostType.INKY:
            threshold = 60 * 15
            break
        case GhostType.CLYDE:
            threshold = 60 * 20
            break
    }

    if (ghost.framesInBox < threshold) {
        return undefined
    }

    return path(ghost.pos, map.spawns[SpawnIndex.GHOST_EXIT], map)
    
}

const updateGhost = (state: GameState, map: Map, type: GhostType) => {
    let ghost: Ghost = state.ghosts[type]

    if (!ghost) {
        ghost = {
            pos: structuredClone(map.spawns[SpawnIndex.GHOST_SPAWN]),
            target: structuredClone(map.spawns[SpawnIndex.GHOST_SPAWN]),
            targetQueue: [],
            type,
            state: GhostState.SCATTER,
            currentDirection: Rotation.EAST,
            hasRespawned: false,
            framesInBox: 0,
        }
        state.ghosts[type] = ghost
    }
    
    let tile = getTile(map, ghost.pos, 0, 0)
    if (tile == Tile.GHOST_WALL || tile == Tile.GHOST_SPAWN) {
        ghost.framesInBox++
    }

    ghost.state = getGhostState(ghost, state)

    if (isStablePos(ghost.pos)) {

        ghost.pos = roundPos(ghost.pos)
    
        let newPath = getGhostPath(ghost, map)
        if (newPath) {
            ghost.targetQueue = newPath
        }

        let frontTile = getTileFrontWithRot(map, ghost.pos, ghost.currentDirection)
        let northTile = getTile(map, ghost.pos, 0, -1)
        let eastTile = getTile(map, ghost.pos, 1, 0) 
        let southTile = getTile(map, ghost.pos, 0, 1)
        let westTile = getTile(map, ghost.pos, -1, 0)

        let isPathing = ghost.targetQueue.length > 0

        let front = canCollide(frontTile, isPathing) 
        let north = canCollide(northTile, isPathing) 
        let east = canCollide(eastTile, isPathing) 
        let south = canCollide(southTile, isPathing) 
        let west = canCollide(westTile, isPathing)

        let isIntersection = 
            (north && east) ||
            (east && south) ||
            (south && west) ||
            (west && north)

        if (isIntersection || !front || (isPathing && vec2eq(ghost.pos, ghost.target))) {
            let target = pickTarget(state, map, type)
            ghost.target = target

            if ((!isIntersection && !front) || isPathing) {
                ghost.currentDirection = undefined
            }
            
            let newRot = ghost.currentDirection
            let min = undefined

            if (north && ghost.currentDirection !== Rotation.SOUTH) {
                let d = dist({x: ghost.pos.x, y: ghost.pos.y - 1}, target)
                if (min === undefined || min > d) {
                    min = d
                    newRot = Rotation.NORTH
                }
            }

            if (east && ghost.currentDirection !== Rotation.WEST) {
                let d = dist({x: ghost.pos.x + 1, y: ghost.pos.y}, target)
                if (min === undefined || min > d) {
                    min = d
                    newRot = Rotation.EAST
                }
            }

            if (south && ghost.currentDirection !== Rotation.NORTH) {
                let d = dist({x: ghost.pos.x, y: ghost.pos.y + 1}, target)
                if (min === undefined || min > d) {
                    min = d
                    newRot = Rotation.SOUTH
                }
            }

            if (west && ghost.currentDirection !== Rotation.EAST) {
                let d = dist({x: ghost.pos.x - 1, y: ghost.pos.y}, target)
                if (min === undefined || min > d) {
                    min = d
                    newRot = Rotation.WEST
                }
            }
            
            ghost.currentDirection = newRot
        }
    }

    incrementPos(ghost.pos, ghost.currentDirection, MOVE_SPEED)
    wrapPos(ghost.pos, map)
    updateKilled(ghost, state)
}

export const updateGhosts = (state: GameState) => {
    let map = getMap(state.mapId)
    if (!map) return

    updateGhost(state, map, GhostType.BLINKY)
    updateGhost(state, map, GhostType.PINKY)
    updateGhost(state, map, GhostType.INKY)
    updateGhost(state, map, GhostType.CLYDE)
}