local QuestManager = {}
QuestManager.__index = QuestManager

-- Initialize a new quest state for a player
function QuestManager.new(player)
    local self = setmetatable({}, QuestManager)
    self.player = player
    self.currentQuest = nil
    self.objectivesTarget = 0
    self.objectivesCleared = 0
    self.isComplete = false
    return self
end

-- Assign a quest to the player
function QuestManager:AssignQuest(questName, requiredKills)
    self.currentQuest = questName
    self.objectivesTarget = requiredKills
    self.objectivesCleared = 0
    self.isComplete = false
    
    print(string.format("Quest '%s' assigned to %s. Target: %d", questName, self.player.Name, requiredKills))
end

-- Register progress securely when an objective is met
function QuestManager:IncrementProgress(amount)
    if not self.currentQuest or self.isComplete then return end
    
    self.objectivesCleared = self.objectivesCleared + amount
    print(string.format("%s progress: %d/%d", self.player.Name, self.objectivesCleared, self.objectivesTarget))
    
    if self.objectivesCleared >= self.objectivesTarget then
        self:CompleteQuest()
    end
end

-- Finalize the quest and award currency/experience
function QuestManager:CompleteQuest()
    self.isComplete = true
    print(string.format("%s successfully finished the quest!", self.player.Name))
    
    -- Reward logic (Server-authoritative)
    local leaderstats = self.player:FindFirstChild("leaderstats")
    if leaderstats then
        local gold = leaderstats:FindFirstChild("Gold")
        if gold then
            gold.Value = gold.Value + 500 -- Safely update value on the server
        end
    end
    
    -- Clear current quest slot
    self.currentQuest = nil
end

return QuestManager