---@diagnostic disable: undefined-global

backgrounds = require("assets.backgrounds.backgrounds-data")
sprite_height = 128
sprite_width = 64

deltaTimeMultiplier = 60

groundTiles = {
    { x = 250,               y = HEIGHT - 300, width = 200,   height = 30 },
    { x = WIDTH - 250 - 200, y = HEIGHT - 300, width = 200,   height = 30 },
    { x = 0,                 y = HEIGHT - 100, width = WIDTH, height = 100 }
}


function SafeInitCharacter(character, default_x, default_y)
    character.x = default_x
    character.x_velocity = 1
    character.y = default_y
    character.y_velocity = 1
    character.current_sprite = character.asset_dir .. "/sprites/idle.png"
    character.default_sprite = character.current_sprite
    character.can_jump = false
    character.knockback_counter = 0
    character.combo_chain = 0
    character.can_apply_knockback = false
end

function Setup()
    local bgIndex = math.random(1, #backgrounds)
    setBgImage(backgrounds[bgIndex])
    SafeInitCharacter(player1Character, 250, 150)
    SafeInitCharacter(player2Character, WIDTH - 250 - (250 / 2), 150)
end

gravity = 1.2 -- POSITIVE gravity

function DrawGroundTiles()
    for _, tile in ipairs(groundTiles) do
        queueRectForRender(tile.x, tile.y, tile.width, tile.height, 100, 100, 100, 255) -- gray boxes
    end
end

function IsOnGround(character)
    for _, tile in ipairs(groundTiles) do
        local characterFeetY = character.y + sprite_height

        local isWithinX = character.x + sprite_width > tile.x and character.x < tile.x + tile.width
        local isTouchingY = characterFeetY >= tile.y and characterFeetY <= tile.y + tile.height
        local isFalling = character.y_velocity >= 0

        if isWithinX and isTouchingY and isFalling then
            character.y = tile.y - sprite_height
            return true
        end
    end
    return false
end

function IsHittingCeiling(character)
    for _, tile in ipairs(groundTiles) do
        local characterHeadY = character.y
        local isWithinX = character.x + sprite_width > tile.x and character.x < tile.x + tile.width
        local isTouchingY = characterHeadY <= tile.y + tile.height and characterHeadY >= tile.y

        if isWithinX and isTouchingY then
            character.y = tile.y + tile.height
            character.y_velocity = 0
            return true
        end
    end
    return false
end

function IsTouchingWall(character, direction)
    for _, tile in ipairs(groundTiles) do
        local charBottom = character.y + sprite_height
        local charTop = character.y
        local tileBottom = tile.y + tile.height
        local tileTop = tile.y

        local verticalOverlap = charBottom > tileTop and charTop < tileBottom

        if direction == "left" then
            local nextX = character.x - character.speed
            local willCollide = nextX < tile.x + tile.width and character.x >= tile.x + tile.width

            if willCollide and verticalOverlap then
                character.x = tile.x + tile.width
                return true
            end
        elseif direction == "right" then
            local nextX = character.x + sprite_width + character.speed
            local willCollide = nextX > tile.x and character.x + sprite_width <= tile.x

            if willCollide and verticalOverlap then
                character.x = tile.x - sprite_width
                return true
            end
        end
    end
    return false
end

function HandleP1Input()
    if Input.isKeyPressedOnce("W") and player1Character.can_jump then
        player1Character.y_velocity = player1Character.jump_strength * -1.0
        player1Character.can_jump = false
    end

    if Input.isKeyDown("D") then
        if not IsTouchingWall(player1Character, "right") then
            player1Character.x_velocity = player1Character.speed
        else
            player1Character.x_velocity = 0
        end
    end
    if Input.isKeyDown("A") then
        if not IsTouchingWall(player1Character, "left") then
            player1Character.x_velocity = -player1Character.speed
        else
            player1Character.x_velocity = 0
        end
    end

    if Input.isKeyPressedOnce("F") then
        PerformPunch(player1Character, player2Character)
    end
end

function HandleP2Input()
    if Input.isKeyPressedOnce("UP") and player2Character.can_jump then
        player2Character.y_velocity = player2Character.jump_strength * -1.0
        player2Character.can_jump = false
    end

    if Input.isKeyDown("RIGHT") then
        if not IsTouchingWall(player2Character, "right") then
            player2Character.x_velocity = player2Character.speed
        else
            player2Character.x_velocity = 0
        end
    end
    if Input.isKeyDown("LEFT") then
        if not IsTouchingWall(player2Character, "left") then
            player2Character.x_velocity = -player2Character.speed
        else
            player2Character.x_velocity = 0
        end
    end

    if Input.isKeyPressedOnce("Right Alt") or Input.isKeyPressedOnce("Right Option") then
        PerformPunch(player2Character, player1Character)
    end
end

function DrawUI()
    local fontFile = "assets/fonts/OpenSans-Bold.ttf"
    local fontSize = 24
    local text = player1Character.name

    local x = 20
    local y = 20

    queueTextForRender(text, fontFile, x, y, fontSize, 0, 0, 0, 255)

    local text = player2Character.name

    local textWidth = getTextWidth(fontFile, fontSize, text)
    local x = WIDTH - textWidth - 20
    local y = 20

    queueTextForRender(text, fontFile, x, y, fontSize, 0, 0, 0, 255)

    local fontFile = "assets/fonts/OpenSans-MediumItalic.ttf"
    local fontSize = 34
    local text = tonumber(player1Character.knockback_counter)

    local x = 40
    local y = 40

    queueTextForRender(text, fontFile, x, y, fontSize, 0, 0, 0, 255)

    local fontFile = "assets/fonts/OpenSans-MediumItalic.ttf"
    local fontSize = 34
    local text = tostring(player2Character.knockback_counter)

    local textWidth = getTextWidth(fontFile, fontSize, text)
    local x = WIDTH - textWidth - 40

    queueTextForRender(text, fontFile, x, y, fontSize, 0, 0, 0, 255)
end

function Respawn(character)
    SafeInitCharacter(character, 250, 150)
end

function ApplyKnockback(attacker, target)
    local knockbackMultiplierX = 0.47
    local knockbackMultiplierY = 0.01
    target.y_velocity = -10 - (target.knockback_counter * knockbackMultiplierY)

    local direction = 1
    if target.x < attacker.x then
        direction = -1
    end

    target.x_velocity = target.knockback_counter * knockbackMultiplierX * direction
    -- target.x = target.x + direction * (target.knockback_counter * 0.7)
end

function ApplyMinimalKnockback(attacker, target)
    local knockbackMultiplierX = 0.47
    local knockbackMultiplierY = 0.01
    local knockbackCountMinimal = 5
    target.y_velocity = -10 - (knockbackCountMinimal * knockbackMultiplierY)

    local direction = 1
    if target.x < attacker.x then
        direction = -1
    end

    target.x_velocity = knockbackCountMinimal * knockbackMultiplierX * direction
    -- target.x = target.x + direction * (target.knockback_counter * 0.7)
end

function KillPlayer(character)
    character.lives = character.lives - 1
    character.knockback_counter = 0
    character.combo_chain = 0
    if character.lives > 0 then
        Respawn(character)
    end
end

function RegisterHit(attacker, target, damage)
    target.knockback_counter = target.knockback_counter + damage
    attacker.combo_chain = attacker.combo_chain + 1

    if attacker.combo_chain >= 4 then
        ApplyKnockback(attacker, target)
        attacker.combo_chain = 0
    else
        ApplyMinimalKnockback(attacker, target)
    end

    if target.knockback_counter >= 1000 then
        KillPlayer(target)
    end
end

function PerformPunch(attacker, target)
    local punch_range = 27
    local punch_height = 80

    -- Determine direction of target relative to attacker
    local punch_direction = (target.x > attacker.x) and "right" or "left"

    -- Set punch sprite
    attacker.current_sprite = attacker.asset_dir .. "/sprites/punch_" .. punch_direction .. ".png"

    -- Reset sprite after a short delay (e.g., 0.15s)
    Timer.clearAllTimers()
    Timer.after(0.15, function()
        attacker.current_sprite = attacker.default_sprite
    end)

    -- Define hitbox based on punch direction
    local hitbox = {
        x = attacker.x + (punch_direction == "right" and sprite_width or -punch_range),
        y = attacker.y + (sprite_height / 2) - (punch_height / 2),
        width = punch_range,
        height = punch_height
    }

    local targetHitbox = {
        x = target.x,
        y = target.y,
        width = sprite_width,
        height = sprite_height
    }

    local function isColliding(a, b)
        return a.x < b.x + b.width and
            a.x + a.width > b.x and
            a.y < b.y + b.height and
            a.y + a.height > b.y
    end

    if isColliding(hitbox, targetHitbox) then
        RegisterHit(attacker, target, attacker.hit_strength)
    end
end

function ApplyPhysics(character)
    local deltaTimeMultiplier = 60 -- Target 60FPS
    character.y_velocity = character.y_velocity + gravity * deltaTime * deltaTimeMultiplier
    character.y = character.y + character.y_velocity * deltaTime * deltaTimeMultiplier
    character.x = character.x + character.x_velocity * deltaTime * deltaTimeMultiplier
    character.x_velocity = character.x_velocity * 0.99

    if character.y_velocity > 0 then
        -- Falling
        if IsOnGround(character) then
            character.y_velocity = 0
            character.can_jump = true
        end
    elseif character.y_velocity < 0 then
        -- Going upward
        IsHittingCeiling(character)
    end

    if not IsOnGround(character) then
        character.can_jump = false
    end

    if character.y > HEIGHT + 50 then
        KillPlayer(character)
    end
end

function Update()
    -- Apply physics
    ApplyPhysics(player1Character)
    ApplyPhysics(player2Character)

    -- Render characters
    queueTextureForRender(player1Character.current_sprite, math.floor(player1Character.x), math.floor(player1Character.y))
    queueTextureForRender(player2Character.current_sprite, math.floor(player2Character.x), math.floor(player2Character.y))

    -- Environment
    DrawGroundTiles()

    -- Input
    HandleP1Input()
    HandleP2Input()

    -- UI
    DrawUI()

    -- Timer
    Timer.update(deltaTime)
end