---
-- @version 0.1.2
-- @location /libs/
-- @author smarrtie

local player = require("player")
local world = require("world")



---@class EntityUtils
---@field reach number The reach distance for entity interactions
---@field closest any The closest entity found
---@field steps number Number of raycast steps for hitbox checking (higher = more accurate but slower)
---@field filter table Keyed map of entities to filter out

---@type EntityUtils
local entityUtils = {}
entityUtils.reach = 3.5
entityUtils.closest = nil
entityUtils.steps = 5
entityUtils.filter = { [player.entity] = false }

---Checks if an entity is in the filter list
---@param entity any The entity to check
---@return boolean returns TRUE if entity is in the filter
function entityUtils.filterEntity(entity)
    if entity and entityUtils.filter[entity] then
        return true
    end
    return false
end

---Adds an entity to the filter list
---@param entity any The entity to add to filter
function entityUtils.addToFilter(entity)
    if entity then
        entityUtils.filter[entity] = true
    end
end

---Removes an entity from the filter list
---@param entity any The entity to remove from filter
function entityUtils.removeFromFilter(entity)
    if entity then
        entityUtils.filter[entity] = false
    end
end

---Gets all entities matching a name (case-insensitive partial match)
---@param name string The name to search for
---@return entity[] Array of matching entities
function entityUtils.getEntitiesByName(name)
    local entities = world.getEntities()
    local scanResult = {}
    local lowerName = string.lower(name)
    for _, entity in pairs(entities) do
        local displayName = string.lower(entity.display_name)
        if displayName:find(lowerName) then
            scanResult[#scanResult + 1] = entity
        end
    end
    return scanResult
end

---Gets the closest valid entity to the player (excluding filtered entities)
---@return any|nil The closest entity, or nil if none found
function entityUtils.getClosestEntity()
    local closest = nil
    local entities = world.getEntities()
    for _, entity in pairs(entities) do
        if not entityUtils.filterEntity(entity) then

            local hasValidBox = entity.box
                and entity.box.maxX and entity.box.minX
                and entity.box.maxY and entity.box.minY
                and entity.box.maxZ and entity.box.minZ
                and entity.box.maxX > entity.box.minX
                and entity.box.maxY > entity.box.minY
                and entity.box.maxZ > entity.box.minZ

            if entity.distance_to_player ~= 0
                and entity.health and entity.health > 0
                and hasValidBox then
                if closest == nil or entity.distance_to_player < closest.distance_to_player then
                    closest = entity
                end
            end
        end
    end
    return closest
end

---Gets the closest living entity to the player (excluding filtered entities)
---@return any|nil The closest living entity, or nil if none found
function entityUtils.getClosestLivingEntity()
    local closest = nil
    local entities = world.getLivingEntities()
    for _, entity in pairs(entities) do
        if not entityUtils.filterEntity(entity) then
            local hasValidBox = entity.box
                and entity.box.maxX and entity.box.minX
                and entity.box.maxY and entity.box.minY
                and entity.box.maxZ and entity.box.minZ
                and entity.box.maxX > entity.box.minX
                and entity.box.maxY > entity.box.minY
                and entity.box.maxZ > entity.box.minZ

            if entity.distance_to_player ~= 0
                and entity.health and entity.health > 0
                and hasValidBox then
                if closest == nil or entity.distance_to_player < closest.distance_to_player then
                    closest = entity
                end
            end
        end
    end
    return closest
end

---Raycasts from entity box to find closest visible point
---@private
---@param box any The box to raycast against
---@return any|nil
local function getBoxRays(box)
    local eyePos = player.getEyePosition()
    local steps = entityUtils.steps
    if not eyePos then return nil end

    local stepX = (box.maxX - box.minX) / (steps - 1)
    local stepY = (box.maxY - box.minY) / (steps - 1)
    local stepZ = (box.maxZ - box.minZ) / (steps - 1)

    local closestPoint = nil
    local minDistance = math.huge

    for ix = 1, steps - 2 do
        for iy = 1, steps - 2 do
            for iz = 1, steps - 2 do
                local px = box.minX + (ix * stepX)
                local py = box.minY + (iy * stepY)
                local pz = box.minZ + (iz * stepZ)

                local ray = world.raycast({
                    startX = eyePos.x,
                    startY = eyePos.y,
                    startZ = eyePos.z,
                    endX = px,
                    endY = py,
                    endZ = pz,
                    include_entity = true,
                })

                local isVisible = true
                if ray ~= nil and ray.type == "entity" then
                    isVisible = true
                end

                if isVisible then
                    local dx = eyePos.x - px
                    local dy = eyePos.y - py
                    local dz = eyePos.z - pz
                    local distSq = (dx * dx) + (dy * dy) + (dz * dz)

                    if distSq < minDistance then
                        minDistance = distSq
                        closestPoint = { x = px, y = py, z = pz }
                    end
                end
            end
        end
    end
    return closestPoint
end

---Gets the closest visible point on an entity's hitbox using raycasting
---@param entity any The entity to check
---@return table|nil Position {x, y, z} of the closest visible hitbox point, or nil if not found
function entityUtils.getClosestHitbox(entity)
    if not entity or not entity.box then
        return nil
    end

    local box = entity.box
    local hasValidBox =
        box.maxX and box.minX
        and box.maxY and box.minY
        and box.maxZ and box.minZ
        and box.maxX > box.minX
        and box.maxY > box.minY
        and box.maxZ > box.minZ
    if not hasValidBox then return nil end

    return getBoxRays(box)
end

return entityUtils