require("GameManager/TutorialTextView")

---Manages multiple named tutorial text views, rendering only the active view.
---
---Views hold their own state independently. Only the current view is rendered
---to the screen. Switching views clears the screen and renders the new view's
---current state.
---
---@class TutorialTextManager
---@field Views table<string, TutorialTextView> All registered views by name.
---@field CurrentViewName string|nil The name of the currently active view.
TutorialTextManager = {}
TutorialTextManager.__index = TutorialTextManager

---Creates a new Tutorial Text Manager.
---@return TutorialTextManager
function TutorialTextManager:New()
    local self = setmetatable({}, TutorialTextManager)

    self.Views = {}
    self.CurrentViewName = nil


    return self
end

---Registers a new view. If a view with the given name already exists it is returned as-is.
---@param name string The view name.
---@return TutorialTextView
function TutorialTextManager:AddView(name)
    if not self.Views[name] then
        self.Views[name] = TutorialTextView:New(name)
    end
    return self.Views[name]
end

---Registers an existing view instance (e.g. a TutorialTextFeed).
---If a view with the same name already exists it is returned as-is.
---@param view TutorialTextView The view to register.
---@return TutorialTextView
function TutorialTextManager:RegisterView(view)
    if not self.Views[view.Name] then
        self.Views[view.Name] = view
    end
    return self.Views[view.Name]
end

---Returns a registered view by name, or nil if it does not exist.
---@param name string The view name.
---@return TutorialTextView|nil
function TutorialTextManager:GetView(name)
    return self.Views[name]
end

---Switches the active view. Clears the screen then renders the new view's current state.
---@param name string The view name to activate.
function TutorialTextManager:SetCurrentView(name)
    if self.CurrentViewName == name then
        return
    end

    local oldView = self.Views[self.CurrentViewName]
    if oldView then
        oldView.IsActive = false
    end

    self:_ClearScreen()
    self.CurrentViewName = name

    local newView = self.Views[name]
    if newView then
        newView.IsActive = true
        self:_RenderView(newView)
    end
end

---Sets or updates a text entry in a view.
---If the view is currently active the change is immediately rendered to the screen.
---@param viewName string The view to update.
---@param key string The unique key for this entry.
---@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 TutorialTextManager:UpdateEntry(viewName, key, text, duration, color)
    local view = self.Views[viewName]
    if not view then
        return
    end

    view:SetEntry(key, text, duration, color)

    if self.CurrentViewName == viewName then
        local entry = view.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 a text entry from a view.
---If the view is currently active the entry is immediately removed from the screen.
---@param viewName string The view to update.
---@param key string The key to remove.
function TutorialTextManager:RemoveEntry(viewName, key)
    local view = self.Views[viewName]
    if not view then
        return
    end

    view:RemoveEntry(key)

    if self.CurrentViewName == viewName then
        Remove_Tutorial_Text(key)
    end
end

---Clears all entries from a view.
---If the view is currently active all entries are immediately removed from the screen.
---@param viewName string The view to clear.
function TutorialTextManager:ClearView(viewName)
    local view = self.Views[viewName]
    if not view then
        return
    end

    if self.CurrentViewName == viewName then
        self:_ClearScreen()
    end

    view:Clear()
end

---Removes all views and clears the screen.
function TutorialTextManager:Reset()
    self:_ClearScreen()
    self.Views = {}
    self.CurrentViewName = nil
end

---Renders all entries of a view to the screen.
---@param view TutorialTextView
function TutorialTextManager:_RenderView(view)
    for _, entry in pairs(view.Entries) do
        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 of the current view from the screen.
function TutorialTextManager:_ClearScreen()
    if not self.CurrentViewName then
        return
    end

    local view = self.Views[self.CurrentViewName]
    if not view then
        return
    end

    for key in pairs(view.Entries) do
        Remove_Tutorial_Text(key)
    end
end

function TutorialTextManager:Debug()
    local count = 0
    for _ in pairs(self.Views) do count = count + 1 end
    return string.format("TutorialTextManager (views: %d, current: '%s')",
        count, self.CurrentViewName or "none")
end