local ns = firefly

Player:listen('init', function(m)
    m.hud_bars = {}
    m.hud_bars_list = {}
end)



function ns.add_hud_bar(m, name, def)
    if m.hud_bars[name] then
        ns.remove_hud_bar(m, name)
    end
    if not def.color then def.color = "#48d" end
    
    local ypos = #m.hud_bars_list *50
    local pixel_scale = 3
    local hud = {
        left = ns.hud_add(m, {
            type = "image",
            image = "firefly_hud_bar_left"..(def.value == 0 and "_bg" or "")..".png^[multiply:"..def.color,
            pos = {x = 0.5, y = 0},
            offset = {x = -400 -pixel_scale, y = ypos +36},
            scale = {x = pixel_scale, y = pixel_scale}
        }),
        center = ns.hud_add(m, {
            type = "image",
            image = "firefly_hud_bar_center_bg.png^[multiply:"..def.color,
            pos = {x = 0.5, y = 0},
            offset = {x = 0, y = ypos +36},
            scale = {x = 800, y = pixel_scale}
        }),
        overlay = ns.hud_add(m, {
            type = "image",
            image = "firefly_hud_bar_center.png^[multiply:"..def.color,
            pos = {x = 0.5, y = 0},
            offset = {x = -400, y = ypos +36},
            align = {x = 1, y = 0},
            scale = {x = 800 *(def.value /def.max), y = pixel_scale}
        }),
        right = ns.hud_add(m, {
            type = "image",
            image = "firefly_hud_bar_right"..(def.value == def.max and "" or "_bg")..".png^[multiply:"..def.color,
            pos = {x = 0.5, y = 0},
            offset = {x = 400 +pixel_scale, y = ypos +36},
            scale = {x = pixel_scale, y = pixel_scale}
        }),
        title = ns.hud_add(m, {
            type = "text",
            text = def.title or "",
            pos = {x = 0.5, y = 0},
            offset = {x = 0, y = ypos +4},
            align = {x = 0, y = 1},
            color = minetest.colorspec_to_table(def.color)
        })
    }
    m.hud_bars[name] = {
        def = def,
        hud = hud,
        index = #m.hud_bars_list +1
    }
    table.insert(m.hud_bars_list, name)
end

function ns.change_hud_bar(m, name, def)
    local bar = m.hud_bars[name]
    if not bar then return end
    local last_value = bar.def.value
    local last_title = bar.def.title
    local last_color = bar.def.color
    extend(bar.def, def)
    if def.value or def.max then
        if last_color ~= bar.def.color then
            bar.hud.right:update(m, {text = "firefly_hud_bar_right"..(def.value == def.max and "" or "_bg")..".png^[multiply:"..def.color})
            bar.hud.left:update(m, {text = "firefly_hud_bar_left"..(def.value == 0 and "_bg" or "")..".png^[multiply:"..def.color})
            bar.hud.center:update(m, {text = "firefly_hud_bar_center_bg.png^[multiply:"..def.color})
            bar.hud.overlay:update(m, {text = "firefly_hud_bar_center.png^[multiply:"..def.color})
            bar.hud.title:update(m, {color = minetest.colorspec_to_table(def.color)})
        end
        
        if bar.def.value == bar.def.max and last_value ~= bar.def.max then
            minetest.after(def.ease or 0.3, function()
                bar.hud.right:update(m, {text = "firefly_hud_bar_right.png^[multiply:"..bar.def.color})
            end)
        elseif last_value == bar.def.max then
            bar.hud.right:update(m, {text = "firefly_hud_bar_right_bg.png^[multiply:"..bar.def.color})
        end
        
        if bar.def.value == 0 and last_value ~= 0 then
            minetest.after(def.ease or 0.3, function()
                bar.hud.left:update(m, {image = "firefly_hud_bar_left_bg.png^[multiply:"..bar.def.color})
            end)
        elseif last_value == 0 then
            bar.hud.left:update(m, {image = "firefly_hud_bar_left.png^[multiply:"..bar.def.color})
        end
        
        if last_title ~= bar.def.title then
            bar.hud.title:update(m, {text = bar.def.title})
        end
        
        bar.hud.overlay:animate {
            scale = {
                value = {x = 800 *(bar.def.value /bar.def.max), y = 3},
                duration = def.ease or 0.3,
                ease_fn = {0.42, 0, 0.58, 1.06}
            }
        }
    end
end

function ns.remove_hud_bar(m, name)
    if not m.hud_bars[name] then return end
    for _, x in pairs(m.hud_bars[name].hud) do
        x:remove(m)
    end
    m.hud_bars[name] = nil
    table.remove(m.hud_bars_list, table.indexof(m.hud_bars_list, name))
    
    -- Reposition all other HUD bars so there are no gaps.
    for i = 1, #m.hud_bars_list do
        local bar = m.hud_bars[m.hud_bars_list[i]]
        if bar.index ~= i then
            local dist = i *50
            bar.hud.right:update(m, {offset = {x = bar.hud.right.offset.x, y = dist +36}})
            bar.hud.left:update(m, {offset = {x = bar.hud.left.offset.x, y = dist +36}})
            bar.hud.center:update(m, {offset = {x = bar.hud.center.offset.x, y = dist +36}})
            bar.hud.overlay:update(m, {offset = {x = bar.hud.overlay.offset.x, y = dist +36}})
            bar.hud.title:update(m, {offset = {x = bar.hud.title.offset.x, y = dist +4}})
        end
    end
end