require("GameManager/TutorialTextView")

---A fixed-capacity feed view. Appending a new line when at capacity evicts the
---oldest (top-most) entry first. Rendering is driven by the IsActive flag set
---by TutorialTextManager; no manager reference is needed.
---
---@class TutorialTextFeed : TutorialTextView
---@field MaxLines integer Maximum number of lines to display at once.
---@field _KeyOrder string[] Insertion-ordered list of active entry keys (oldest first).
---@field _NextId integer Counter used to generate unique entry keys.
TutorialTextFeed = setmetatable({}, { __index = TutorialTextView })
TutorialTextFeed.__index = TutorialTextFeed

---Creates a new Tutorial Text Feed.
---@param name string The view name.
---@param maxLines integer Maximum number of lines to display at once.
---@return TutorialTextFeed
function TutorialTextFeed:New(name, maxLines)
    local self = setmetatable(TutorialTextView:New(name), TutorialTextFeed)

    ---@cast self TutorialTextFeed
    self.MaxLines = maxLines
    self._KeyOrder = {}
    self._NextId = 0

    return self
end

---Appends a new line to the bottom of the feed.
---If the feed is at capacity, the oldest line is removed first.
---Only renders to the screen when this view is active.
---@param text string The display text.
---@param duration number|nil Duration in seconds, defaults to -1 (infinite).
---@param color ColorStruct|nil The text color, defaults to white.
function TutorialTextFeed:Append(text, duration, color)
    ---@diagnostic disable-next-line
    if table.getn(self._KeyOrder) >= self.MaxLines then
        local oldestKey = table.remove(self._KeyOrder, 1)
        self.Entries[oldestKey] = nil
        if self.IsActive then
            Remove_Tutorial_Text(oldestKey)
        end
    end

    self._NextId = self._NextId + 1
    local key = self.Name .. "_" .. self._NextId

    self:SetEntry(key, text, duration, color)
    table.insert(self._KeyOrder, key)

    if self.IsActive then
        local entry = self.Entries[key]
        Add_Tutorial_Text(entry.Key, entry.Text, entry.Duration,
            entry.Color.R, entry.Color.G, entry.Color.B, entry.Color.A)
    end
end

---Removes all entries from the feed.
---Only clears the screen when this view is active.
function TutorialTextFeed:Clear()
    if self.IsActive then
        for _, key in ipairs(self._KeyOrder) do
            Remove_Tutorial_Text(key)
        end
    end
    self.Entries = {}
    self._KeyOrder = {}
end

function TutorialTextFeed:Debug()
    return string.format("TutorialTextFeed '%s' (%d/%d lines)",
        ---@diagnostic disable-next-line
        self.Name, table.getn(self._KeyOrder), self.MaxLines)
end