-- TODO show some text on screen for a short while?
-- TODO "admin" command version with configurable pos, radius and timeout

local announce_command_name = "look"
local announce_radius = 256 -- players within this radius will see a waypoint
local announce_icon = "exclamation_mark.png"
local announce_timeout = 20 -- time until waypoint disappears
local waypoint_precision = 1 -- set to 1 to show whole number or 10 for 1 decimal
local waypoint_color = 0xFFFFFF
local point_range = 180 -- maximun range player can point at (raycast range)
local point_to_objects = true
local point_to_liquids = true


-- return first thing player is pointing at
local function raycast_crosshair(player, range)
    local p_pos = player:get_pos()
    local p_eye_height = player:get_properties().eye_height
    local p_eye_pos = { x = p_pos.x, y = p_pos.y + p_eye_height, z = p_pos.z }
    local to = vector.add(p_eye_pos, vector.multiply(player:get_look_dir(), range))
    local ray = minetest.raycast(p_eye_pos, to, point_to_objects, point_to_liquids)
    local pointed_thing = ray:next()
    while pointed_thing do
        if pointed_thing.type == "object" and pointed_thing.ref == player then
            -- exclude the player themselves from the raycast
            pointed_thing = ray:next()
        else
            return pointed_thing
        end
    end
end


local function get_pointed_position(player, range)
    local pointed_thing = raycast_crosshair(player, range)
    local pointed_pos = nil
    if pointed_thing then
        if pointed_thing.type == "node" then
            pointed_pos = vector.multiply(vector.add(pointed_thing.above, pointed_thing.under), 0.5)
        elseif pointed_thing.type == "object" then
            pointed_pos = pointed_thing.ref:get_pos()
        end
    end
    return pointed_pos, pointed_thing
end


local function show_hud_waypoint(player, point_pos, name, icon_name)
    local hud_id1 = player:hud_add({
            hud_elem_type = "waypoint",
            name = name,
            text = "m", -- distance suffix
            precision = waypoint_precision,
            number = waypoint_color,
            world_pos = point_pos,
            offset = {x=0,y=0},
            alignment = {x=0, y=1},
    })

    local hud_id2 = player:hud_add({
            hud_elem_type = "image_waypoint",
            scale = {x=-3,y=-3},
            text = icon_name,
            alignment = {x=0,y=-1},
            world_pos = point_pos,
            offset = {x=0,y=0},
            --name = name,
            --precision = waypoint_precision,
            --number = waypoint_color,
    })
    local hud_ids = {hud_id1, hud_id2}
    return hud_ids
end


local function hide_hud_waypoint(player_name, hud_ids)
    local player = minetest.get_player_by_name(player_name)
    if player then
        for _,hud_id in pairs(hud_ids) do
            player:hud_remove(hud_id)
        end
    end
end


local prepared_announcements = {}
local function prepare_announcement(announcer_name, announce_radius, message, announce_icon, announce_timeout)
    --prepared_announcements[select(1,...)] = table.pack(...) -- does not work in older lua?
    prepared_announcements[announcer_name] = {announcer_name, announce_radius, message, announce_icon, announce_timeout}
end


local function add_announcement(announcer, announcer_name, radius, message, icon_name, timeout)
    local player_pos = announcer:get_pos()
    -- TODO use pointed thing to provide some description?
    local pointed_pos, pointed_thing = get_pointed_position(announcer, point_range)
    if not pointed_pos then
        -- player is pointing into the void, use him as target
        pointed_pos = player_pos
    end
    
    for i, object in pairs(minetest.get_objects_inside_radius(player_pos, radius)) do
        if object:is_player() then
            local player = object
            local player_name = player:get_player_name()
            local hud_ids = show_hud_waypoint(player, pointed_pos, message, icon_name)
            minetest.after(announce_timeout, hide_hud_waypoint, player_name, hud_ids)
        end
    end
    
    local rounded_pos = vector.round(pointed_pos)
    minetest.chat_send_all(minetest.colorize("#FF90A8",
                                             "[ANNOUNCE] (" ..
                                             announcer_name ..
                                             ") Look: " .. message .. " " ..
                                             minetest.pos_to_string(rounded_pos)))

end


local function check_click_for_prepared_players(dtime)
    for player_name, prepared_args in pairs(prepared_announcements) do
        local player = minetest.get_player_by_name(player_name)
        if player then
            local player_controls = player:get_player_control()
            if player_controls['dig'] then
                -- place prepared announcement at pointed position
                add_announcement(player, unpack(prepared_args))
                prepared_announcements[player_name] = nil
            elseif player_controls['place'] then
                -- cancel prepared announcement
                minetest.chat_send_player(player_name, "Announcement canceled.")
                prepared_announcements[player_name] = nil
            end
        else
            -- player is not online anymore, remove prepared announcement
            prepared_announcements[player_name] = nil
        end
    end
end


minetest.register_globalstep(check_click_for_prepared_players)

    
minetest.register_chatcommand(announce_command_name, {
    privs = {
        shout = true,
    },
    func = function(name, param)
        local player = minetest.get_player_by_name(name)
        if player then          -- player is online
            local player_name = player:get_player_name()
            -- TODO limit message length?
            prepare_announcement(player_name, announce_radius, param, announce_icon, announce_timeout)
            return true, "Prepared announcement: \"" .. param .. "\". Point and <hit> where to put it. (<place> to cancel)."
        else
            return false
        end
    end,
})