// Copyright (c) Pixel Crushers. All rights reserved.

using UnityEngine;
using System;

namespace PixelCrushers.QuestMachine
{

    public enum CounterValueConditionMode { AtLeast, AtMost }

    /// <summary>
    /// Quest condition that becomes true when a counter reaches a specified value.
    /// </summary>
    public class CounterQuestCondition : QuestCondition
    {

        [Tooltip("Index of a counter defined in the quest. Inspect the quest's main info to view/edit counters.")]
        [SerializeField]
        private int m_counterIndex;

        [Tooltip("How the counter value applies to the condition.")]
        [SerializeField]
        private CounterValueConditionMode m_counterValueMode = CounterValueConditionMode.AtLeast;

        [Tooltip("The required value for the Counter Value Mode.")]
        [SerializeField]
        private QuestNumber m_requiredCounterValue;

        [NonSerialized]
        private QuestCounter m_counter = null;

        /// <summary>
        /// Index of a counter defined in the quest. Inspect the quest's main info to view/edit counters.
        /// </summary>
        public int counterIndex
        {
            get { return m_counterIndex; }
            set { m_counterIndex = value; }
        }

        /// <summary>
        /// How the counter value applies to the condition.
        /// </summary>
        public CounterValueConditionMode counterValueMode
        {
            get { return m_counterValueMode; }
            set { m_counterValueMode = value; }
        }

        /// <summary>
        /// The required value for the Counter Value Mode.
        /// </summary>
        public QuestNumber requiredCounterValue
        {
            get { return m_requiredCounterValue; }
            set { m_requiredCounterValue = value; }
        }

        public QuestCounter counter
        {
            get
            {
                if (m_counter == null) m_counter = quest.GetCounter(counterIndex);
                return m_counter;
            }
        }

        public override string GetEditorName()
        {
            var counter = (quest != null) ? quest.GetCounter(counterIndex) : null;
            if (counter == null || requiredCounterValue == null) return "Counter";
            return "Counter: " + counter.name + (counterValueMode == CounterValueConditionMode.AtLeast ? " >= " : " <= ") + requiredCounterValue.GetEditorName(quest);
        }

        public override void StartChecking(System.Action trueAction)
        {
            base.StartChecking(trueAction);
            if (quest == null)
            {
                if (Debug.isDebugBuild) Debug.LogWarning("Quest Machine: CounterQuestCondition was passed a null quest. Can't start checking.");
                return;
            }
            if (counter == null)
            {
                if (Debug.isDebugBuild) Debug.LogWarning("Quest Machine: CounterQuestCondition can't find a counter at index " + counterIndex + 
                        "' in quest '" + quest.GetEditorName() + "'.  Can't start checking.");
                return;
            }
            if (IsCounterConditionTrue(counter))
            {
                SetTrue();
            }
            else
            {
                counter.changed -= OnCounterChanged;
                counter.changed += OnCounterChanged;
            }
        }

        public override void StopChecking()
        {

            base.StopChecking();
            if (counter != null) counter.changed -= OnCounterChanged;
        }

        protected virtual void OnCounterChanged(QuestCounter counter)
        {
            if (IsCounterConditionTrue(counter)) SetTrue();
        }

        protected virtual bool IsCounterConditionTrue(QuestCounter counter)
        { 
            if (counter == null) return false;
            if (requiredCounterValue == null)
            {
                if (Debug.isDebugBuild) Debug.LogWarning("Quest Machine: QuestCounterCondition.OnCounterChanged(" + StringField.GetStringValue(counter.name) + " = " + counter.currentValue + "): requiredCounterValue field is null. Please contact the developer.", quest);
                return false;
            }
            if (QuestMachine.debug) Debug.Log("Quest Machine: QuestCounterCondition.OnCounterChanged(" + StringField.GetStringValue(counter.name) + " = " + counter.currentValue + ")", quest);
            switch (counterValueMode)
            {
                case CounterValueConditionMode.AtLeast:
                    if (counter.currentValue >= requiredCounterValue.GetValue(quest)) return true;
                    break;
                case CounterValueConditionMode.AtMost:
                    if (counter.currentValue <= requiredCounterValue.GetValue(quest)) return true;
                    break;
            }
            return false;
        }

    }
}