using System.Text.Json;
using Chessistics.Engine.Loading;
using Chessistics.Engine.Model;
using Xunit;

namespace Chessistics.Tests.Loading;

public class CampaignLoaderTests
{
    private const string ValidCampaignJson = """
    {
      "name": "La Quête du Roi",
      "initialWidth": 4,
      "initialHeight": 4,
      "missions": [
        {
          "id": 1,
          "name": "Premier Convoi",
          "description": "Les pions découvrent une scierie.",
          "terrainPatch": {
            "newWidth": 4,
            "newHeight": 4,
            "cells": [
              { "col": 0, "row": 0, "type": "production", "production": { "name": "Scierie", "cargo": "wood", "amount": 1 } },
              { "col": 3, "row": 0, "type": "demand", "demand": { "name": "Dépôt", "cargo": "wood", "amount": 3 } }
            ]
          },
          "unlockedPieces": ["pawn"],
          "unlockedLevels": [{ "kind": "pawn", "level": 1 }],
          "stock": [{ "kind": "pawn", "count": 6 }]
        },
        {
          "id": 2,
          "name": "Forger les Tours",
          "description": "De nouveaux territoires s'ouvrent.",
          "terrainPatch": {
            "newWidth": 6,
            "newHeight": 4,
            "cells": [
              { "col": 4, "row": 0, "type": "empty" },
              { "col": 4, "row": 1, "type": "wall" },
              { "col": 5, "row": 2, "type": "production", "production": { "name": "Carrière", "cargo": "stone", "amount": 1 } },
              { "col": 5, "row": 3, "type": "demand", "demand": { "name": "Chantier", "cargo": "stone", "amount": 5 } }
            ]
          },
          "unlockedPieces": ["rook"],
          "unlockedLevels": [{ "kind": "rook", "level": 1 }],
          "stock": [
            { "kind": "pawn", "count": 2 },
            { "kind": "rook", "count": 3 }
          ]
        }
      ]
    }
    """;

    [Fact]
    public void LoadValidCampaign_ParsesCorrectly()
    {
        var campaign = CampaignLoader.Load(ValidCampaignJson);

        Assert.Equal("La Quête du Roi", campaign.Name);
        Assert.Equal(4, campaign.InitialWidth);
        Assert.Equal(4, campaign.InitialHeight);
        Assert.Equal(2, campaign.Missions.Count);
    }

    [Fact]
    public void LoadValidCampaign_Mission1_Correct()
    {
        var campaign = CampaignLoader.Load(ValidCampaignJson);
        var m1 = campaign.Missions[0];

        Assert.Equal(1, m1.Id);
        Assert.Equal("Premier Convoi", m1.Name);
        Assert.Equal(4, m1.TerrainPatch.NewWidth);
        Assert.Equal(2, m1.TerrainPatch.Cells.Count);
        Assert.Single(m1.UnlockedPieces);
        Assert.Equal(PieceKind.Pawn, m1.UnlockedPieces[0]);
        Assert.Single(m1.Stock);
        Assert.Equal(6, m1.Stock[0].Count);
    }

    [Fact]
    public void LoadValidCampaign_Mission2_TerrainExpands()
    {
        var campaign = CampaignLoader.Load(ValidCampaignJson);
        var m2 = campaign.Missions[1];

        Assert.Equal(6, m2.TerrainPatch.NewWidth);
        Assert.Equal(4, m2.TerrainPatch.NewHeight);

        var wallCell = m2.TerrainPatch.Cells.First(c => c.Type == CellType.Wall);
        Assert.Equal(4, wallCell.Col);
        Assert.Equal(1, wallCell.Row);
    }

    [Fact]
    public void LoadCampaign_ShrinkingTerrain_Throws()
    {
        var badJson = """
        {
          "name": "Bad",
          "initialWidth": 6,
          "initialHeight": 6,
          "missions": [
            {
              "id": 1, "name": "M1",
              "terrainPatch": { "newWidth": 4, "newHeight": 4, "cells": [] },
              "stock": []
            }
          ]
        }
        """;

        Assert.Throws<JsonException>(() => CampaignLoader.Load(badJson));
    }

    [Fact]
    public void LoadCampaign_EmptyName_Throws()
    {
        var badJson = """
        {
          "name": "",
          "initialWidth": 4,
          "initialHeight": 4,
          "missions": [{ "id": 1, "name": "M", "terrainPatch": { "newWidth": 4, "newHeight": 4, "cells": [] } }]
        }
        """;

        Assert.Throws<JsonException>(() => CampaignLoader.Load(badJson));
    }

    [Fact]
    public void LoadCampaign_NoMissions_Throws()
    {
        var badJson = """
        {
          "name": "Empty",
          "initialWidth": 4,
          "initialHeight": 4,
          "missions": []
        }
        """;

        Assert.Throws<JsonException>(() => CampaignLoader.Load(badJson));
    }

    [Fact]
    public void LoadCampaign_TransformerCell_ParsesCorrectly()
    {
        var json = """
        {
          "name": "Forge Test",
          "initialWidth": 5,
          "initialHeight": 1,
          "missions": [
            {
              "id": 1, "name": "M1",
              "terrainPatch": {
                "newWidth": 5, "newHeight": 1,
                "cells": [
                  { "col": 0, "row": 0, "type": "production", "production": { "name": "Scierie", "cargo": "wood", "amount": 4 } },
                  { "col": 2, "row": 0, "type": "transformer", "transformer": { "name": "Forge", "inputCargo": "wood", "inputRequired": 2, "outputCargo": "tools", "outputAmount": 1 } },
                  { "col": 4, "row": 0, "type": "demand", "demand": { "name": "Depot", "cargo": "tools", "amount": 3 } }
                ]
              },
              "stock": [{ "kind": "rook", "count": 3 }],
              "unlockedPieces": ["rook"],
              "unlockedLevels": [{ "kind": "rook", "level": 1 }]
            }
          ]
        }
        """;

        var campaign = CampaignLoader.Load(json);
        var cells = campaign.Missions[0].TerrainPatch.Cells;

        var transformerCell = cells.First(c => c.Type == CellType.Transformer);
        Assert.NotNull(transformerCell.Transformer);
        Assert.Equal("Forge", transformerCell.Transformer.Name);
        Assert.Equal(CargoType.Wood, transformerCell.Transformer.InputCargo);
        Assert.Equal(2, transformerCell.Transformer.InputRequired);
        Assert.Equal(CargoType.Tools, transformerCell.Transformer.OutputCargo);
        Assert.Equal(1, transformerCell.Transformer.OutputAmount);
    }

    [Fact]
    public void LoadCampaign_NewCargoTypes_ParseCorrectly()
    {
        var json = """
        {
          "name": "Cargo Test",
          "initialWidth": 3,
          "initialHeight": 1,
          "missions": [
            {
              "id": 1, "name": "M1",
              "terrainPatch": {
                "newWidth": 3, "newHeight": 1,
                "cells": [
                  { "col": 0, "row": 0, "type": "demand", "demand": { "name": "D1", "cargo": "arms", "amount": 1 } },
                  { "col": 1, "row": 0, "type": "demand", "demand": { "name": "D2", "cargo": "gold", "amount": 1 } },
                  { "col": 2, "row": 0, "type": "demand", "demand": { "name": "D3", "cargo": "tools", "amount": 1 } }
                ]
              },
              "stock": []
            }
          ]
        }
        """;

        var campaign = CampaignLoader.Load(json);
        var cells = campaign.Missions[0].TerrainPatch.Cells;

        Assert.Equal(CargoType.Arms, cells[0].Demand!.Cargo);
        Assert.Equal(CargoType.Gold, cells[1].Demand!.Cargo);
        Assert.Equal(CargoType.Tools, cells[2].Demand!.Cargo);
    }
}