using Service.AI;

namespace WebApi.Controllers;

[ApiController]
[Route("api/[controller]/[action]")]
public class TransactionCategoryController(
    ITransactionCategoryRepository categoryRepository,
    ITransactionRecordRepository transactionRecordRepository,
    ILogger<TransactionCategoryController> logger,
    IBudgetRepository budgetRepository,
    IOpenAiService openAiService
) : ControllerBase
{
    /// <summary>
    /// 获取分类列表（支持按类型筛选）
    /// </summary>
    [HttpGet]
    public async Task<BaseResponse<List<TransactionCategory>>> GetListAsync([FromQuery] TransactionType? type = null)
    {
        try
        {
            List<TransactionCategory> categories;
            if (type.HasValue)
            {
                categories = await categoryRepository.GetCategoriesByTypeAsync(type.Value);
            }
            else
            {
                categories = (await categoryRepository.GetAllAsync()).ToList();
            }

            return categories.Ok();
        }
        catch (Exception ex)
        {
            logger.LogError(ex, "获取分类列表失败");
            return $"获取分类列表失败: {ex.Message}".Fail<List<TransactionCategory>>();
        }
    }

    /// <summary>
    /// 根据ID获取分类详情
    /// </summary>
    [HttpGet("{id}")]
    public async Task<BaseResponse<TransactionCategory>> GetByIdAsync(long id)
    {
        try
        {
            var category = await categoryRepository.GetByIdAsync(id);
            if (category == null)
            {
                return "分类不存在".Fail<TransactionCategory>();
            }

            return category.Ok();
        }
        catch (Exception ex)
        {
            logger.LogError(ex, "获取分类详情失败, Id: {Id}", id);
            return $"获取分类详情失败: {ex.Message}".Fail<TransactionCategory>();
        }
    }

    /// <summary>
    /// 创建分类
    /// </summary>
    [HttpPost]
    public async Task<BaseResponse<long>> CreateAsync([FromBody] CreateCategoryDto dto)
    {
        try
        {
            // 检查同名分类
            var existing = await categoryRepository.GetByNameAndTypeAsync(dto.Name, dto.Type);
            if (existing != null)
            {
                return "已存在相同名称的分类".Fail<long>();
            }

            var category = new TransactionCategory
            {
                Name = dto.Name,
                Type = dto.Type
            };

            var result = await categoryRepository.AddAsync(category);
            if (result)
            {
                return category.Id.Ok();
            }

            return "创建分类失败".Fail<long>();
        }
        catch (Exception ex)
        {
            logger.LogError(ex, "创建分类失败, Dto: {@Dto}", dto);
            return $"创建分类失败: {ex.Message}".Fail<long>();
        }
    }

    /// <summary>
    /// 更新分类
    /// </summary>
    [HttpPost]
    public async Task<BaseResponse> UpdateAsync([FromBody] UpdateCategoryDto dto)
    {
        try
        {
            var category = await categoryRepository.GetByIdAsync(dto.Id);
            if (category == null)
            {
                return "分类不存在".Fail();
            }

            // 如果修改了名称，检查同名
            if (category.Name != dto.Name)
            {
                var existing = await categoryRepository.GetByNameAndTypeAsync(dto.Name, category.Type);
                if (existing != null && existing.Id != dto.Id)
                {
                    return "已存在相同名称的分类".Fail();
                }

                // 同步更新交易记录中的分类名称
                await transactionRecordRepository.UpdateCategoryNameAsync(category.Name, dto.Name, category.Type);
                await budgetRepository.UpdateBudgetCategoryNameAsync(category.Name, dto.Name, category.Type);
            }

            category.Name = dto.Name;
            category.UpdateTime = DateTime.Now;

            var success = await categoryRepository.UpdateAsync(category);
            if (success)
            {
                return "更新分类成功".Ok();
            }

            return "更新分类失败".Fail();
        }
        catch (Exception ex)
        {
            logger.LogError(ex, "更新分类失败, Dto: {@Dto}", dto);
            return $"更新分类失败: {ex.Message}".Fail();
        }
    }

    /// <summary>
    /// 删除分类
    /// </summary>
    [HttpPost]
    public async Task<BaseResponse> DeleteAsync([FromQuery] long id)
    {
        try
        {
            // 检查是否被使用
            var inUse = await categoryRepository.IsCategoryInUseAsync(id);
            if (inUse)
            {
                return "该分类已被使用，无法删除".Fail();
            }

            var success = await categoryRepository.DeleteAsync(id);
            if (success)
            {
                return BaseResponse.Done();
            }

            return "删除分类失败，分类不存在".Fail();
        }
        catch (Exception ex)
        {
            logger.LogError(ex, "删除分类失败, Id: {Id}", id);
            return $"删除分类失败: {ex.Message}".Fail();
        }
    }

    /// <summary>
    /// 批量创建分类（用于初始化）
    /// </summary>
    [HttpPost]
    public async Task<BaseResponse<int>> BatchCreateAsync([FromBody] List<CreateCategoryDto> dtoList)
    {
        try
        {
            var categories = dtoList.Select(dto => new TransactionCategory
            {
                Name = dto.Name,
                Type = dto.Type
            }).ToList();

            var result = await categoryRepository.AddRangeAsync(categories);
            if (result)
            {
                return categories.Count.Ok();
            }

            return "批量创建分类失败".Fail<int>();
        }
        catch (Exception ex)
        {
            logger.LogError(ex, "批量创建分类失败, Count: {Count}", dtoList.Count);
            return $"批量创建分类失败: {ex.Message}".Fail<int>();
        }
    }

    /// <summary>
    /// 为指定分类生成新的SVG图标
    /// </summary>
    [HttpPost]
    public async Task<BaseResponse<string>> GenerateIconAsync([FromBody] GenerateIconDto dto)
    {
        try
        {
            var category = await categoryRepository.GetByIdAsync(dto.CategoryId);
            if (category == null)
            {
                return "分类不存在".Fail<string>();
            }

            // 使用AI生成简洁的SVG图标
            var systemPrompt = @"你是一个SVG图标生成专家。请生成简洁、现代的单色SVG图标。
要求：
1. 只返回<svg>标签及其内容，不要其他说明文字
2. viewBox=""0 0 24 24""
3. 尺寸为24x24
4. 使用单色，fill=""currentColor""
5. 简洁的设计，适合作为应用图标";

            var userPrompt = $"为分类\"{category.Name}\"（{(category.Type == TransactionType.Expense ? "支出" : category.Type == TransactionType.Income ? "收入" : "不计收支")}）生成一个SVG图标";

            var svgContent = await openAiService.ChatAsync(systemPrompt, userPrompt, timeoutSeconds: 30);
            if (string.IsNullOrWhiteSpace(svgContent))
            {
                return "AI生成图标失败".Fail<string>();
            }

            // 提取SVG标签内容
            var svgMatch = System.Text.RegularExpressions.Regex.Match(svgContent, @"<svg[^>]*>.*?</svg>", 
                System.Text.RegularExpressions.RegexOptions.Singleline);
            
            if (!svgMatch.Success)
            {
                return "生成的内容不包含有效的SVG标签".Fail<string>();
            }

            var svg = svgMatch.Value;

            // 解析现有图标数组
            var icons = string.IsNullOrWhiteSpace(category.Icon) 
                ? new List<string>() 
                : JsonSerializer.Deserialize<List<string>>(category.Icon) ?? new List<string>();

            // 添加新图标
            icons.Add(svg);

            // 更新数据库
            category.Icon = JsonSerializer.Serialize(icons);
            category.UpdateTime = DateTime.Now;
            
            var success = await categoryRepository.UpdateAsync(category);
            if (!success)
            {
                return "更新分类图标失败".Fail<string>();
            }

            return svg.Ok<string>();
        }
        catch (Exception ex)
        {
            logger.LogError(ex, "生成图标失败, CategoryId: {CategoryId}", dto.CategoryId);
            return $"生成图标失败: {ex.Message}".Fail<string>();
        }
    }

    /// <summary>
    /// 更新分类的选中图标索引
    /// </summary>
    [HttpPost]
    public async Task<BaseResponse> UpdateSelectedIconAsync([FromBody] UpdateSelectedIconDto dto)
    {
        try
        {
            var category = await categoryRepository.GetByIdAsync(dto.CategoryId);
            if (category == null)
            {
                return "分类不存在".Fail();
            }

            // 验证索引有效性
            if (string.IsNullOrWhiteSpace(category.Icon))
            {
                return "该分类没有可用图标".Fail();
            }

            var icons = JsonSerializer.Deserialize<List<string>>(category.Icon);
            if (icons == null || dto.SelectedIndex < 0 || dto.SelectedIndex >= icons.Count)
            {
                return "无效的图标索引".Fail();
            }

            // 这里可以添加一个SelectedIconIndex字段到实体中，或者将选中的图标移到数组第一位
            // 暂时采用移动到第一位的方式
            var selectedIcon = icons[dto.SelectedIndex];
            icons.RemoveAt(dto.SelectedIndex);
            icons.Insert(0, selectedIcon);

            category.Icon = JsonSerializer.Serialize(icons);
            category.UpdateTime = DateTime.Now;

            var success = await categoryRepository.UpdateAsync(category);
            if (success)
            {
                return "更新图标成功".Ok();
            }

            return "更新图标失败".Fail();
        }
        catch (Exception ex)
        {
            logger.LogError(ex, "更新选中图标失败, Dto: {@Dto}", dto);
            return $"更新选中图标失败: {ex.Message}".Fail();
        }
    }
}

/// <summary>
/// 创建分类DTO
/// </summary>
public record CreateCategoryDto(
    string Name,
    TransactionType Type
);

/// <summary>
/// 更新分类DTO
/// </summary>
public record UpdateCategoryDto(
    long Id,
    string Name
);

/// <summary>
/// 生成图标DTO
/// </summary>
public record GenerateIconDto(
    long CategoryId
);

/// <summary>
/// 更新选中图标DTO
/// </summary>
public record UpdateSelectedIconDto(
    long CategoryId,
    int SelectedIndex
);