function widget:GetInfo()
    return {
        name    = "Holo Place",
        desc    = "Start next building while nearby nano turrets are free",
        author  = "manshanko",
        date    = "2025-04-14",
        home    = "https://github.com/manshanko/bar-widgets",
        layer   = 2,
        handler = true,
    }
end

if Spring.GetSpectatingState() then return end

local echo = Spring.Echo
local i18n = Spring.I18N
local GetSelectedUnits = Spring.GetSelectedUnits
local GetUnitBuildeeRadius = Spring.GetUnitBuildeeRadius
local GetUnitCommandCount = Spring.GetUnitCommandCount
local GetUnitDefID = Spring.GetUnitDefID
local GetUnitIsBeingBuilt = Spring.GetUnitIsBeingBuilt
local GetUnitIsBuilding = Spring.GetUnitIsBuilding
local GetUnitCommands = Spring.GetUnitCommands
local GetUnitCurrentCommand = Spring.GetUnitCurrentCommand
local GetUnitPosition = Spring.GetUnitPosition
local GetUnitSeparation = Spring.GetUnitSeparation
local GetUnitsInCylinder = Spring.GetUnitsInCylinder
local GiveOrderToUnit = Spring.GiveOrderToUnit
local UnitDefs = UnitDefs
local CMD_REPAIR = CMD.REPAIR
local CMD_REMOVE = CMD.REMOVE
local CMD_FIGHT = CMD.FIGHT

local CMD_HOLO_PLACE = 28339
local CMD_HOLO_PLACE_DESCRIPTION = {
    id = CMD_HOLO_PLACE,
    type = CMDTYPE.ICON_MODE,
    name = "Holo Place",
    cursor = nil,
    action = "holo_place",
    params = { 0, "holo_place_off", "holo_place_on" }
}

i18n.set("en.ui.orderMenu." .. CMD_HOLO_PLACE_DESCRIPTION.params[2], "Holo Place")
i18n.set("en.ui.orderMenu." .. CMD_HOLO_PLACE_DESCRIPTION.params[3], "Holo Place")
i18n.set("en.ui.orderMenu." .. CMD_HOLO_PLACE_DESCRIPTION.action .. "_tooltip", "Start next building while nearby nano turrets are free")

local BUILDER_DEFS = {}
local NANO_DEFS = {}
local BT_DEFS = {}
local MAX_DISTANCE = 0
local HOLO_PLACERS = {}

for unit_def_id, unit_def in pairs(UnitDefs) do
    BT_DEFS[unit_def_id] = unit_def.buildTime
    if unit_def.isBuilder and not unit_def.isFactory then
        if #unit_def.buildOptions > 0 then
            BUILDER_DEFS[unit_def_id] = unit_def.buildSpeed
        end
        if not unit_def.canMove then
            NANO_DEFS[unit_def_id] = unit_def.buildDistance
            if unit_def.buildDistance > MAX_DISTANCE then
                MAX_DISTANCE = unit_def.buildDistance
            end
        end
    end
end

local function ntNearUnit(target_unit_id, callback)
    local buildee_radius = GetUnitBuildeeRadius(target_unit_id) - 1
    local x, y, z = GetUnitPosition(target_unit_id)
    local units_near = GetUnitsInCylinder(x, z, MAX_DISTANCE + buildee_radius, -2)
    for i=1, #units_near do
        local id = units_near[i]
        if not GetUnitIsBeingBuilt(id) then
            local dist = NANO_DEFS[GetUnitDefID(id)]
            if dist ~= nil and target_unit_id ~= id then
                if dist > GetUnitSeparation(target_unit_id, id, true, true) then
                    if callback(id) then
                        return
                    end
                end
            end
        end
    end
end

local function checkUnits(update)
    local builders = {}
    local has_holo_place = false

    local ids = GetSelectedUnits()
    for i=1, #ids do
        local unit_id = ids[i]
        local def_id = GetUnitDefID(unit_id)

        if BUILDER_DEFS[def_id] then
            if HOLO_PLACERS[ids[i]] then
                has_holo_place = true
            end

            builders[#builders + 1] = unit_id
        end
    end

    if #builders > 0 then
        if update then
            if has_holo_place then
                for i=1, #builders do
                    HOLO_PLACERS[builders[i]] = nil
                end
                has_holo_place = false
            else
                for i=1, #builders do
                    HOLO_PLACERS[builders[i]] = HOLO_PLACERS[builders[i]] or {}
                end
                has_holo_place = true
            end
        end

        if has_holo_place then
            CMD_HOLO_PLACE_DESCRIPTION.params[1] = 1
        else
            CMD_HOLO_PLACE_DESCRIPTION.params[1] = 0
        end

        return true
    end
end

local function handleHoloPlace()
    checkUnits(true)
end

function widget:MetaUnitRemoved(unit_id)
    HOLO_PLACERS[unit_id] = nil
end

function widget:CommandsChanged()
    if checkUnits(false) then
        local cmds = widgetHandler.customCommands
        cmds[#cmds + 1] = CMD_HOLO_PLACE_DESCRIPTION
    end
end

function widget:CommandNotify(cmd_id, cmd_params, cmd_options)
    if cmd_id == CMD_HOLO_PLACE then
        checkUnits(true)
        return true
    end
end

function widget:GameFrame()
    for unit_id, builder in pairs(HOLO_PLACERS) do
        local target_id = GetUnitIsBuilding(unit_id)
        if builder.nt_id and target_id == builder.building_id then
            local building_id = GetUnitIsBuilding(builder.nt_id)
            local num_cmds = GetUnitCommands(builder.nt_id, 0)
            if building_id == builder.building_id and num_cmds == 1 then
                builder.nt_id = false
                GiveOrderToUnit(unit_id, CMD_REMOVE, builder.cmd_tag, 0)
            elseif builder.tick > 30 then
                builder.nt_id = false
                builder.building_id = false
            else
                builder.tick = builder.tick + 1
            end
        elseif target_id and target_id ~= builder.building_id then
            -- find nearby nano to pin holo

            ntNearUnit(target_id, function(nt_id)
                local cmds = GetUnitCommands(nt_id, 2)

                if (cmds[2] and cmds[2].id == CMD_FIGHT)
                    or (cmds[1] and cmds[1].id == CMD_FIGHT)
                then
                    local _, _, tag = GetUnitCurrentCommand(unit_id)
                    builder.nt_id = nt_id
                    builder.tick = 0
                    builder.building_id = target_id
                    builder.cmd_tag = tag
                    GiveOrderToUnit(nt_id, CMD_REPAIR, target_id, 0)
                    return true
                end
            end)
        end
    end
end

function widget:Initialize()
    widgetHandler.actionHandler:AddAction(self, "holo_place", handleHoloPlace, nil, "p")
end

function widget:Shutdown()
    widgetHandler.actionHandler:RemoveAction(self, "holo_place", "p")
end