ComfyFactorio/maps/planet_prison/mod/ai.lua

local public = {}
local _common = require('.common')

public.command = {
    --[[
      @param args nil
   --]]
    noop = 0,
    --[[
      @param args nil
   --]]
    seek_and_destroy_player = 1,
    --[[
      @param args = {
          agents, // All movable agents
          positions, // Table of positions to attack
      }
   --]]
    attack_objects = 2
}

local function _get_direction(src, dest)
    local src_x = _common.get_axis(src, 'x')
    local src_y = _common.get_axis(src, 'y')
    local dest_x = _common.get_axis(dest, 'x')
    local dest_y = _common.get_axis(dest, 'y')

    local step = {
        x = nil,
        y = nil
    }

    local precision = _common.rand_range(1, 10)
    if dest_x - precision > src_x then
        step.x = 1
    elseif dest_x < src_x - precision then
        step.x = -1
    else
        step.x = 0
    end

    if dest_y - precision > src_y then
        step.y = 1
    elseif dest_y < src_y - precision then
        step.y = -1
    else
        step.y = 0
    end

    return _common.direction_lookup[step.x][step.y]
end

local function _move_to(ent, trgt, min_distance)
    local state = {
        walking = false
    }

    local distance = _common.get_distance(trgt.position, ent.position)
    if min_distance < distance then
        local dir = _get_direction(ent.position, trgt.position)
        if dir then
            state = {
                walking = true,
                direction = dir
            }
        end
    end

    ent.walking_state = state
    return state.walking
end

local function _shoot_at(ent, trgt)
    ent.shooting_state = {
        state = defines.shooting.shooting_enemies,
        position = trgt.position
    }
end

local function _shoot_stop(ent)
    ent.shooting_state = {
        state = defines.shooting.not_shooting,
        position = {0, 0}
    }
end

local function _do_job_seek_and_destroy_player(surf)
    for _, player in pairs(game.players) do
        if player.character == nil then
            goto continue
        end

        local search_info = {
            name = 'character',
            position = player.character.position,
            radius = 20,
            force = 'enemy'
        }

        local ents = surf.find_entities_filtered(search_info)
        if not ents or #ents == 0 then
            goto continue
        end

        for _, e in pairs(ents) do
            if not _move_to(e, player.character, _common.rand_range(5, 10)) then
                _shoot_at(e, player.character)
            else
                _shoot_stop(e)
            end
        end

        ::continue::
    end
end

local function _do_job_attack_objects(surf, args)
    local agents = args.agents
    if #agents == 0 then
        return
    end

    local objects = args.objects
    local target, closest, agent, query
    for i = #agents, 1, -1 do
        agent = agents[i]
        if not agent.valid then
            table.remove(agents, i)
            goto continue
        end

        if game.tick % i ~= 0 then
            goto continue
        end

        query = {
            position = agent.position,
            radius = 15,
            type = {
                'projectile',
                'beam'
            },
            force = {
                'enemy',
                'player',
                'neutral'
            },
            invert = true
        }
        closest = surf.find_entities_filtered(query)
        if #closest ~= 0 then
            target = _common.get_closest_neighbour(agent.position, closest)
        else
            if #objects == 0 then
                _shoot_stop(agent)
                goto continue
            end

            target = _common.get_closest_neighbour(agent.position, objects)
        end

        if target == nil or not target.valid then
            goto continue
        end

        if not _move_to(agent, target, _common.rand_range(5, 15)) then
            _shoot_at(agent, target)
        else
            _shoot_stop(agent)
        end

        ::continue::
    end
end

--[[
do_job - Perform non-stateful operation on all enemy "character" entities.
@param surf - LuaSurface, on which everything is happening.
@param command - Command to perform on all non-player controllable characters.
--]]
public.do_job = function(surf, command, args)
    if args == nil then
        args = {}
    end

    if command == public.command.seek_and_destroy_player then
        _do_job_seek_and_destroy_player(surf)
    elseif command == public.command.attack_objects then
        _do_job_attack_objects(surf, args)
    end
end

return public