using Barotrauma.Items.Components;
using Microsoft.Xna.Framework;
using System;
using System.Linq;

namespace Barotrauma
{
    class AIObjectiveRepairItem : AIObjective
    {
        private Item item;
        
        public AIObjectiveRepairItem(Character character, Item item)
            : base(character, "")
        {
            this.item = item;
        }

        public override float GetPriority(AIObjectiveManager objectiveManager)
        {
            bool insufficientSkills = true;
            bool repairablesFound = false;
            foreach (Repairable repairable in item.Repairables)
            {
                if (item.Condition > repairable.ShowRepairUIThreshold) { continue; }
                if (repairable.DegreeOfSuccess(character) >= 0.5f) { insufficientSkills = false; }
                repairablesFound = true;
            }

            if (!repairablesFound) { return 0.0f; }

            float priority = item.Prefab.Health - item.Condition;
            //vertical distance matters more than horizontal (climbing up/down is harder than moving horizontally)
            float dist = 
                Math.Abs(character.WorldPosition.X - item.WorldPosition.X) + 
                Math.Abs(character.WorldPosition.Y - item.WorldPosition.Y) * 2.0f;

            //heavily increase the priority if the item is already selected 
            //so characters don't keep switching between nearby damaged items
            if (character.SelectedConstruction == item)
            {
                priority += 50.0f;
            }
            if (insufficientSkills)
            {
                return MathHelper.Lerp(0.0f, 50.0f, priority / 100.0f / Math.Max(dist / 100.0f, 1.0f));
            }
            else
            {
                return MathHelper.Lerp(50.0f, 100.0f, priority / 100.0f / Math.Max(dist / 100.0f, 1.0f));
            }
        }

        public override bool IsCompleted()
        {
            foreach (Repairable repairable in item.Repairables)
            {
                if (item.Condition < Math.Max(repairable.ShowRepairUIThreshold, item.Prefab.Health * 0.98f)) return false;
            }
            
            character?.Speak(TextManager.Get("DialogItemRepaired").Replace("[itemname]", item.Name), null, 0.0f, "itemrepaired", 10.0f);
            return true;
        }

        public override bool IsDuplicate(AIObjective otherObjective)
        {
            return otherObjective is AIObjectiveRepairItem repairObjective && repairObjective.item == item;
        }

        protected override void Act(float deltaTime)
        {
            foreach (Repairable repairable in item.Repairables)
            {
                //make sure we have all the items required to fix the target item
                foreach (var kvp in repairable.requiredItems)
                {
                    foreach (RelatedItem requiredItem in kvp.Value)
                    {
                        if (!character.Inventory.Items.Any(it => it != null && requiredItem.MatchesItem(it)))
                        {
                            AddSubObjective(new AIObjectiveGetItem(character, requiredItem.Identifiers, true));
                            return;
                        }
                    }
                }
            }

            if (character.CanInteractWith(item))
            {
                foreach (Repairable repairable in item.Repairables)
                {
                    if (character.SelectedConstruction != item) { item.TryInteract(character, true, true); }
                    repairable.CurrentFixer = character;
                    break;
                }
            }
            else
            {
                AddSubObjective(new AIObjectiveGoTo(item, character));
            }
        }
    }
}