--[[-- Control - Help Bubbles
Adds friendly biters that walk around and give helpful messages
]]

local Async = require("modules/exp_util/async")
local Storage = require("modules/exp_util/storage")
local Feature = require("modules/exp_scenario/features")
local community_details = require("modules/exp_scenario/config/community_details").config

local feature = Feature.register("help_bubbles")

--- Ticks between message changes
local message_cycle = 60 * 15

local locations = {
    ["Spawn"] = {
        spawn_position = { x = 0, y = 0 },
        spawn_surface = "nauvis",
        entity_name = "small-biter",
        --- Built each cycle so changes to community_details show without a restart
        messages = function()
            return {
                { "info.website", community_details.website },
                { "info.read-readme" },
                { "info.discord", community_details.discord },
                { "info.softmod" },
                { "info.redmew" },
                { "info.custom-commands" },
                { "info.status", community_details.status },
                { "info.lhd" },
                { "info.github", community_details.github },
                { "info.patreon", community_details.patreon },
            }
        end,
    }

}

--- @type table<string, Async.AsyncReturn<any>>
local persistent_locations = {}
Storage.register(persistent_locations, function(tbl)
    persistent_locations = tbl
end)

--- @class speech_bubble_task_param
--- @field entity LuaEntity
--- @field messages LocalisedString[]?
--- @field location string? Used when there are no messages, a key of locations
--- @field previous_message LuaEntity?
--- @field current_message_index number

--- Used by create_entity within speech_bubble_async
local speech_bubble_param = {
    name = "compi-speech-bubble",
    position = { 0, 0 },
}

--- Cycle between a set category of messages above an entity
local speech_bubble_task =
    Async.register(function(task)
        --- @cast task speech_bubble_task_param
        local entity = task.entity
        if not entity.valid then
            return Async.status.complete()
        end

        local messages = task.messages or locations[task.location].messages()
        local index = task.current_message_index
        if index > #messages then
            index = 1
        end

        local previous_message = task.previous_message
        if previous_message and previous_message.valid then
            previous_message.destroy()
        end

        speech_bubble_param.source = entity
        speech_bubble_param.text = messages[index]
        task.previous_message = entity.surface.create_entity(speech_bubble_param)

        task.current_message_index = index + 1
        return Async.status.delay(message_cycle, task)
    end)

--- Register an entity to start spawning speech bubbles
--- @param entity LuaEntity the entity which will have messages spawn from it
--- @param messages LocalisedString[] the messages which should be shown
--- @param starting_index number? the message index to start at, default 1
--- @return Async.AsyncReturn<any>
local function register_entity(entity, messages, starting_index)
    return speech_bubble_task{
        entity = entity,
        messages = messages,
        current_message_index = starting_index or 1,
    }
end

--- Check all persistent locations from the config are active
local function check_persistent_locations()
    for name, location in pairs(locations) do
        local task = persistent_locations[name]
        if task and not task.completed then
            goto continue
        end

        local surface = game.get_surface(location.spawn_surface)
        if not surface then
            goto continue
        end

        local position = surface.find_non_colliding_position(location.entity_name, location.spawn_position, 1.5, 0.5)
        if not position then
            goto continue
        end

        local entity = surface.create_entity{ name = location.entity_name, position = position, force = game.forces.neutral }
        if not entity then
            goto continue
        end

        persistent_locations[name] = speech_bubble_task{
            entity = entity,
            location = name,
            current_message_index = 1,
        }
        ::continue::
    end
end

return feature:guard{
    on_nth_tick = {
        [message_cycle] = check_persistent_locations,
    },
    register_entity = register_entity,
}