using System;
using System.Collections.Generic;
using System.IO;
using UnityEngine;

namespace Ironspore
{
    [Serializable]
    public sealed class CargoStack
    {
        public string uid = Guid.NewGuid().ToString("N");
        public string itemId;
        public int count;
        public CargoStack(string id, int amount)
        {
            itemId = id;
            count = amount;
        }
        public string Name => GameLocalization.ItemName(itemId);
    }

    [Serializable]
    public sealed class RunRecord
    {
        public string id;
        public bool active;
        public int seed;
        public int stage;
        public int branch;
        public int biome;
        public int chassis = 1;
        public int[] equipment = { 0, 0, 0, 0 };
        public float armor;
        public float energy = 100;
        public bool podUsed;
        public bool objectiveDone;
        public bool routeCompleted;
        public int upgrades;
        public float elapsed;
        public float escortArmor = 250;
        public List<CargoStack> cargo = new List<CargoStack>();
        public List<string> searched = new List<string>();
    }

    [Serializable]
    public sealed class GameSave
    {
        public int version = 1;
        public int alloy;
        public int cells;
        public int sorties;
        public int extractions;
        public int completed;
        public List<string> blueprints = new List<string>();
        public List<string> unlocked = new List<string>();
        public List<string> receipts = new List<string>();
        public RunRecord run = new RunRecord();
    }

    public sealed class ProfileStore
    {
        readonly string path;
        public GameSave Data
        {
            get; private set;
        }
        public string Error
        {
            get; private set;
        }

        public ProfileStore(string savePath)
        {
            path = savePath;
            Data = Load(path) ?? Load(path + ".bak") ?? new GameSave();
        }

        static GameSave Load(string file)
        {
            try
            {
                if (!File.Exists(file))
                    return null;
                var save = JsonUtility.FromJson<GameSave>(File.ReadAllText(file));
                if (save == null || save.version != 1 || save.run == null || save.receipts == null || save.blueprints == null || save.unlocked == null)
                    return null;
                if (save.run.cargo == null || save.run.equipment == null || save.run.equipment.Length != 4)
                    return null;
                return save;
            }
            catch (Exception) { return null; }
        }

        public bool Commit(Func<GameSave, bool> change)
        {
            var candidate = JsonUtility.FromJson<GameSave>(JsonUtility.ToJson(Data));
            if (!change(candidate))
                return false;
            try
            {
                Directory.CreateDirectory(Path.GetDirectoryName(path));
                string temp = path + ".tmp";
                using (var stream = new FileStream(temp, FileMode.Create, FileAccess.Write, FileShare.None))
                {
                    byte[] bytes = System.Text.Encoding.UTF8.GetBytes(JsonUtility.ToJson(candidate, true));
                    stream.Write(bytes, 0, bytes.Length);
                    stream.Flush(true);
                }
                if (File.Exists(path))
                    File.Replace(temp, path, path + ".bak");
                else
                    File.Move(temp, path);
                Data = candidate;
                Error = null;
                return true;
            }
            catch (Exception ex) { Error = ex.Message; return false; }
        }

        public bool Begin(int chassis, int[] equipment, float armor, int seed)
        {
            return Commit(s =>
            {
                s.run = new RunRecord { id = Guid.NewGuid().ToString("N"), active = true, seed = seed, chassis = chassis, equipment = (int[])equipment.Clone(), armor = armor };
                s.sorties++;
                return true;
            });
        }

        public bool AddCargo(string id, int count, string sourceKey = "")
        {
            if (count <= 0)
                return false;
            return Commit(s =>
            {
                if (!s.run.active)
                    return false;
                if (sourceKey.Length > 0 && s.run.searched.Contains(sourceKey))
                    return false;
                foreach (var stack in s.run.cargo)
                {
                    if (id.StartsWith("blueprint_") || stack.itemId != id || stack.count + count > 10)
                        continue;
                    stack.count += count;
                    if (sourceKey.Length > 0)
                        s.run.searched.Add(sourceKey);
                    return true;
                }
                if (s.run.cargo.Count >= 4 || (id.StartsWith("blueprint_") ? count != 1 : count > 10))
                    return false;
                s.run.cargo.Add(new CargoStack(id, count));
                if (sourceKey.Length > 0)
                    s.run.searched.Add(sourceKey);
                return true;
            });
        }

        static void Bank(GameSave s, CargoStack stack)
        {
            if (stack.itemId == "alloy")
                s.alloy += stack.count;
            else if (stack.itemId == "cells")
                s.cells += stack.count;
            else if (!s.blueprints.Contains(stack.itemId))
                s.blueprints.Add(stack.itemId);
            else
                s.alloy += 2;
        }

        public bool SendCargo(IReadOnlyCollection<string> selection)
        {
            if (selection == null || selection.Count == 0 || selection.Count > 2)
                return false;
            var ids = new HashSet<string>(selection);
            if (ids.Count != selection.Count)
                return false;
            return Commit(s =>
            {
                string receipt = s.run.id + ":cargo";
                if (!s.run.active || s.run.armor <= 0 || s.run.podUsed || s.receipts.Contains(receipt))
                    return false;
                var picked = s.run.cargo.FindAll(x => ids.Contains(x.uid));
                if (picked.Count != ids.Count)
                    return false;
                foreach (var stack in picked)
                {
                    Bank(s, stack);
                    s.run.cargo.Remove(stack);
                }
                s.run.podUsed = true;
                s.receipts.Add(receipt);
                return true;
            });
        }

        public bool Finish(bool destroyed)
        {
            return Commit(s =>
            {
                string receipt = s.run.id + ":return";
                if (!s.run.active || s.receipts.Contains(receipt))
                    return false;
                if (!destroyed)
                {
                    foreach (var stack in s.run.cargo)
                        Bank(s, stack);
                    s.extractions++;
                }
                s.run.cargo.Clear();
                s.run.active = false;
                s.receipts.Add(receipt);
                return true;
            });
        }

        public bool CompleteRoute()
        {
            return Commit(s =>
            {
                if (!s.run.active || s.run.armor <= 0 || s.run.routeCompleted)
                    return false;
                s.run.routeCompleted = true;
                s.run.objectiveDone = true;
                s.completed++;
                return true;
            });
        }
    }
}