using CodePlay.Core.Interfaces;
using CodePlay.Core.Models;
using CodePlay.Core.Common;

namespace CodePlay.Core.Validators;

/// <summary>
/// 自动修复引擎
/// </summary>
public class AutoFixEngine : IAutoFixEngine
{
    /// <summary>
    /// 尝试修复编译错误
    /// </summary>
    public Task<FixResult> FixAsync(string code, List<CompilationError> errors, int round, CancellationToken cancellationToken = default)
    {
        var result = new FixResult
        {
            CanFix = false,
            RemainingErrors = new List<CompilationError>()
        };
        
        if (errors == null || errors.Count == 0)
        {
            result.CanFix = true;
            result.FixedCode = code;
            return Task.FromResult(result);
        }
        
        var fixedCode = code;
        var remainingErrors = new List<CompilationError>();
        
        switch (round)
        {
            case 1:
                // 第 1 轮：修复导入/using 语句
                result = FixRound1(code, errors);
                break;
                
            case 2:
                // 第 2 轮：修复类型映射
                result = FixRound2(code, errors);
                break;
                
            case 3:
                // 第 3 轮：修复 API 调用
                result = FixRound3(code, errors);
                break;
                
            default:
                result.RemainingErrors = errors;
                break;
        }
        
        return Task.FromResult(result);
    }
    
    /// <summary>
    /// 第 1 轮：修复导入/using 语句
    /// </summary>
    private FixResult FixRound1(string code, List<CompilationError> errors)
    {
        var result = new FixResult
        {
            CanFix = false,
            RemainingErrors = new List<CompilationError>()
        };
        
        var needsSystemUsing = false;
        var needsCollectionsUsing = false;
        var needsLinqUsing = false;
        
        foreach (var error in errors)
        {
            if (error.ErrorId == "CS0246" || error.ErrorId == "CS0103")
            {
                // 类型或命名空间找不到
                if (error.Message.Contains("Console"))
                {
                    needsSystemUsing = true;
                }
                else if (error.Message.Contains("List") || error.Message.Contains("Dictionary"))
                {
                    needsCollectionsUsing = true;
                }
                else if (error.Message.Contains("LINQ") || error.Message.Contains("var"))
                {
                    needsLinqUsing = true;
                }
                else
                {
                    result.RemainingErrors.Add(error);
                }
            }
            else
            {
                result.RemainingErrors.Add(error);
            }
        }
        
        // 添加缺失的 using
        var fixedCode = code;
        var fixDescription = new StringBuilder();
        
        if (needsSystemUsing && !code.Contains("using System;"))
        {
            fixedCode = fixedCode.Insert(0, "using System;\n");
            fixDescription.Append("Added using System; ");
        }
        
        if (needsCollectionsUsing && !code.Contains("using System.Collections.Generic;"))
        {
            fixedCode = fixedCode.Insert(0, "using System.Collections.Generic;\n");
            fixDescription.Append("Added using System.Collections.Generic;");
        }
        
        if (needsLinqUsing && !code.Contains("using System.Linq;"))
        {
            fixedCode = fixedCode.Insert(0, "using System.Linq;\n");
            fixDescription.Append("Added using System.Linq;");
        }
        
        if (fixDescription.Length > 0)
        {
            result.CanFix = true;
            result.FixedCode = fixedCode;
            result.FixDescription = fixDescription.ToString();
        }
        else
        {
            result.CanFix = false;
            result.RemainingErrors = errors;
        }
        
        return result;
    }
    
    /// <summary>
    /// 第 2 轮：修复类型映射
    /// </summary>
    private FixResult FixRound2(string code, List<CompilationError> errors)
    {
        var result = new FixResult
        {
            CanFix = false,
            RemainingErrors = new List<CompilationError>()
        };
        
        var fixedCode = code;
        var hasFixes = false;
        
        foreach (var error in errors)
        {
            // Java 到 C# 的类型映射问题
            if (error.ErrorId == "CS0246")
            {
                if (error.Message.Contains("String"))
                {
                    fixedCode = fixedCode.Replace("String", "string");
                    hasFixes = true;
                }
                else if (error.Message.Contains("ArrayList"))
                {
                    fixedCode = fixedCode.Replace("ArrayList", "List<object>");
                    hasFixes = true;
                }
                else if (error.Message.Contains("HashMap"))
                {
                    fixedCode = fixedCode.Replace("HashMap", "Dictionary<object, object>");
                    hasFixes = true;
                }
                else
                {
                    result.RemainingErrors.Add(error);
                }
            }
            else
            {
                result.RemainingErrors.Add(error);
            }
        }
        
        if (hasFixes)
        {
            result.CanFix = true;
            result.FixedCode = fixedCode;
            result.FixDescription = "Applied type mapping fixes";
        }
        else
        {
            result.RemainingErrors = errors;
        }
        
        return result;
    }
    
    /// <summary>
    /// 第 3 轮：修复 API 调用
    /// </summary>
    private FixResult FixRound3(string code, List<CompilationError> errors)
    {
        var result = new FixResult
        {
            CanFix = false,
            RemainingErrors = errors
        };
        
        // 这轮通常是复杂修复，MVP 版本暂不实现
        // 可以考虑修复一些常见的 API 调用差异
        
        return result;
    }
}