local g = require("scripts.libs.gradient")

---@class ColoredText
---@field text string
---@field color string

---@param name string
---@param gradient Gradient
---@param count number number of gradients to be present in the span
---@param phase_shift number shift of the gradient
---@returns string
local function render_gradient_name(name, gradient, count, phase_shift)
    local string_width = client.getTextWidth(name) / count;
    local string_width_chars = {};
    for i = 1, #name do
        string_width_chars[i] = client.getTextWidth(name:sub(i, i))
    end

    ---@type ColoredText[]
    local result = {}

    local acc = 0;
    for i = 1, #name do
        local offset = acc + string_width_chars[i];
        local color = gradient:at((offset / string_width) + phase_shift);
        acc = offset

        result[i] = {
            text = name:sub(i, i),
            color = color:toHex(true, false)
        }
    end

    return toJson(result)
end

---@param name string
---@param gradient Gradient
---@param nameplates Nameplate | Nameplate[] where to use the animated name
---@param count number number of gradients to be present in the span
---@param phase_shift_rate number how fast to shift the gradient
---@returns fun():void # function to unregister
local function animate_gradient_name(name, gradient, nameplates, count, phase_shift_rate)
    if type(nameplates) ~= "table" then
        nameplates = {nameplates}
    end

    local phase_shift = 0;
    local function render()
        if client.isPaused() then
            return
        end

        phase_shift = phase_shift + phase_shift_rate

        local result = render_gradient_name(name, gradient, count, phase_shift)
        for _, nameplate in pairs(nameplates) do
            nameplate:setText(result)
        end
    end

    events.render:register(render)
    return function ()
        events.render:remove(render)
    end
end

---@param name string
---@param gradient Gradient
---@param nameplates Nameplate | Nameplate[] where to use the static name
---@param count number number of gradients to be present in the span
---@param phase_shift number shift of the gradient
local function static_gradient_name(name, gradient, nameplates, count, phase_shift)
    if type(nameplates) ~= "table" then
        nameplates = {nameplates}
    end

    local result = render_gradient_name(name, gradient, count, phase_shift);
    for _, nameplate in pairs(nameplates) do
        nameplate:setText(result)
    end
end

local name = "reidlab!"
local gradient_count = 1
local gradient = g.SimpleGradientBuilder.new()
    :add({ "#d87b5a", "#e0ab91" })
    :reflect(false)
    :build()

animate_gradient_name(name, gradient, {
    nameplate.ENTITY,
    nameplate.LIST
}, gradient_count, 0.005)

static_gradient_name(name, gradient, {
    nameplate.CHAT
}, gradient_count, 0)