using Microsoft.Extensions.Logging;
using OrpaonVision.Core.Results;
using OrpaonVision.Model.Security;
using OrpaonVision.ConfigApp.Infrastructure.Services;

namespace OrpaonVision.ConfigApp.Infrastructure.Services;

/// <summary>
/// 权限管理服务实现。
/// </summary>
public sealed class PermissionService : IPermissionService
{
    private readonly ILogger<PermissionService> _logger;
    private readonly List<PermissionModel> _permissions;

    /// <summary>
    /// 构造函数。
    /// </summary>
    public PermissionService(ILogger<PermissionService> logger)
    {
        _logger = logger;
        _permissions = new List<PermissionModel>();
        
        InitializeSampleData();
    }

    /// <inheritdoc />
    public Result<PermissionModel> CreatePermission(PermissionModel permission)
    {
        try
        {
            if (permission == null)
            {
                return Result<PermissionModel>.Fail("PERMISSION_NULL", "权限不能为空。");
            }

            if (string.IsNullOrWhiteSpace(permission.Code))
            {
                return Result<PermissionModel>.Fail("PERMISSION_CODE_REQUIRED", "权限编码不能为空。");
            }

            // 检查权限编码是否已存在
            if (_permissions.Any(p => p.Code.Equals(permission.Code, StringComparison.OrdinalIgnoreCase)))
            {
                return Result<PermissionModel>.Fail("PERMISSION_CODE_EXISTS", "权限编码已存在。");
            }

            _logger.LogInformation("正在创建权限: {PermissionCode}", permission.Code);

            permission.Id = Guid.NewGuid();
            permission.Status = PermissionStatus.Enabled;
            permission.SortOrder = _permissions.Count + 1;
            permission.CreatedAtUtc = DateTime.UtcNow;
            permission.UpdatedAtUtc = DateTime.UtcNow;

            _permissions.Add(permission);

            _logger.LogInformation("权限创建成功: {PermissionId} - {PermissionCode}", permission.Id, permission.Code);
            return Result<PermissionModel>.Success(permission, message: "权限创建成功。");
        }
        catch (Exception ex)
        {
            var traceId = Guid.NewGuid().ToString("N");
            _logger.LogError(ex, "创建权限失败。TraceId: {TraceId}", traceId);
            var result = Result.FromException(ex, "CREATE_PERMISSION_FAILED", "创建权限失败。", traceId);
            return Result<PermissionModel>.FailWithTrace(result.Code, result.Message, result.TraceId ?? traceId, result.Errors.ToArray());
        }
    }

    /// <inheritdoc />
    public Result<PermissionModel> UpdatePermission(PermissionModel permission)
    {
        try
        {
            if (permission == null)
            {
                return Result<PermissionModel>.Fail("PERMISSION_NULL", "权限不能为空。");
            }

            var existingPermission = _permissions.FirstOrDefault(p => p.Id == permission.Id);
            if (existingPermission == null)
            {
                return Result<PermissionModel>.Fail("PERMISSION_NOT_FOUND", $"未找到ID为 {permission.Id} 的权限。");
            }

            _logger.LogInformation("正在更新权限: {PermissionId} - {PermissionCode}", permission.Id, permission.Code);

            existingPermission.Name = permission.Name;
            existingPermission.Description = permission.Description;
            existingPermission.Module = permission.Module;
            existingPermission.Action = permission.Action;
            existingPermission.SortOrder = permission.SortOrder;
            existingPermission.Remark = permission.Remark;
            existingPermission.UpdatedAtUtc = DateTime.UtcNow;
            existingPermission.UpdatedBy = permission.UpdatedBy;

            _logger.LogInformation("权限更新成功: {PermissionId} - {PermissionCode}", permission.Id, permission.Code);
            return Result<PermissionModel>.Success(existingPermission, message: "权限更新成功。");
        }
        catch (Exception ex)
        {
            var traceId = Guid.NewGuid().ToString("N");
            _logger.LogError(ex, "更新权限失败。TraceId: {TraceId}", traceId);
            var result = Result.FromException(ex, "UPDATE_PERMISSION_FAILED", "更新权限失败。", traceId);
            return Result<PermissionModel>.FailWithTrace(result.Code, result.Message, result.TraceId ?? traceId, result.Errors.ToArray());
        }
    }

    /// <inheritdoc />
    public Result DeletePermission(Guid permissionId)
    {
        try
        {
            var permission = _permissions.FirstOrDefault(p => p.Id == permissionId);
            if (permission == null)
            {
                return Result.Fail("PERMISSION_NOT_FOUND", $"未找到ID为 {permissionId} 的权限。");
            }

            if (permission.IsSystemPermission)
            {
                return Result.Fail("CANNOT_DELETE_SYSTEM_PERMISSION", "不能删除系统权限。");
            }

            _logger.LogInformation("正在删除权限: {PermissionId} - {PermissionCode}", permission.Id, permission.Code);

            _permissions.Remove(permission);

            _logger.LogInformation("权限删除成功: {PermissionId} - {PermissionCode}", permission.Id, permission.Code);
            return Result.Success(message: "权限删除成功。");
        }
        catch (Exception ex)
        {
            var traceId = Guid.NewGuid().ToString("N");
            _logger.LogError(ex, "删除权限失败。TraceId: {TraceId}", traceId);
            var result = Result.FromException(ex, "DELETE_PERMISSION_FAILED", "删除权限失败。", traceId);
            return Result.FailWithTrace(result.Code, result.Message, result.TraceId ?? traceId, result.Errors.ToArray());
        }
    }

    /// <inheritdoc />
    public Result<PermissionModel> GetPermissionById(Guid permissionId)
    {
        try
        {
            var permission = _permissions.FirstOrDefault(p => p.Id == permissionId);
            if (permission == null)
            {
                return Result<PermissionModel>.Fail("PERMISSION_NOT_FOUND", $"未找到ID为 {permissionId} 的权限。");
            }

            return Result<PermissionModel>.Success(permission, message: "获取权限成功。");
        }
        catch (Exception ex)
        {
            var traceId = Guid.NewGuid().ToString("N");
            _logger.LogError(ex, "获取权限失败。TraceId: {TraceId}", traceId);
            var result = Result.FromException(ex, "GET_PERMISSION_FAILED", "获取权限失败。", traceId);
            return Result<PermissionModel>.FailWithTrace(result.Code, result.Message, result.TraceId ?? traceId, result.Errors.ToArray());
        }
    }

    /// <inheritdoc />
    public Result<PagedResult<PermissionModel>> GetPermissionPagedList(int pageIndex = 1, int pageSize = 20, PermissionStatus? status = null, string? keyword = null)
    {
        try
        {
            var query = _permissions.AsQueryable();

            // 状态过滤
            if (status.HasValue)
            {
                query = query.Where(p => p.Status == status.Value);
            }

            // 关键词搜索
            if (!string.IsNullOrWhiteSpace(keyword))
            {
                query = query.Where(p => 
                    p.Code.Contains(keyword, StringComparison.OrdinalIgnoreCase) ||
                    p.Name.Contains(keyword, StringComparison.OrdinalIgnoreCase) ||
                    p.Module.Contains(keyword, StringComparison.OrdinalIgnoreCase));
            }

            // 排序
            query = query.OrderBy(p => p.Module).ThenBy(p => p.SortOrder).ThenBy(p => p.Code);

            var totalCount = query.Count();
            var items = query.Skip((pageIndex - 1) * pageSize).Take(pageSize).ToList();

            var pagedResult = PagedResult<PermissionModel>.Success(items, totalCount, pageIndex, pageSize);

            return Result<PagedResult<PermissionModel>>.Success(pagedResult, message: "获取权限列表成功。");
        }
        catch (Exception ex)
        {
            var traceId = Guid.NewGuid().ToString("N");
            _logger.LogError(ex, "获取权限列表失败。TraceId: {TraceId}", traceId);
            var result = Result.FromException(ex, "GET_PERMISSION_LIST_FAILED", "获取权限列表失败。", traceId);
            return Result<PagedResult<PermissionModel>>.FailWithTrace(result.Code, result.Message, result.TraceId ?? traceId, result.Errors.ToArray());
        }
    }

    /// <inheritdoc />
    public Result<List<PermissionModel>> GetEnabledPermissions()
    {
        try
        {
            var enabledPermissions = _permissions
                .Where(p => p.Status == PermissionStatus.Enabled)
                .OrderBy(p => p.Module)
                .ThenBy(p => p.SortOrder)
                .ThenBy(p => p.Code)
                .ToList();

            return Result<List<PermissionModel>>.Success(enabledPermissions, message: "获取启用权限列表成功。");
        }
        catch (Exception ex)
        {
            var traceId = Guid.NewGuid().ToString("N");
            _logger.LogError(ex, "获取启用权限列表失败。TraceId: {TraceId}", traceId);
            var result = Result.FromException(ex, "GET_ENABLED_PERMISSIONS_FAILED", "获取启用权限列表失败。", traceId);
            return Result<List<PermissionModel>>.FailWithTrace(result.Code, result.Message, result.TraceId ?? traceId, result.Errors.ToArray());
        }
    }

    /// <inheritdoc />
    public Result<List<PermissionModel>> GetPermissionsByModule(string module)
    {
        try
        {
            if (string.IsNullOrWhiteSpace(module))
            {
                return Result<List<PermissionModel>>.Fail("MODULE_REQUIRED", "模块名称不能为空。");
            }

            var modulePermissions = _permissions
                .Where(p => p.Module.Equals(module, StringComparison.OrdinalIgnoreCase) && p.Status == PermissionStatus.Enabled)
                .OrderBy(p => p.SortOrder)
                .ThenBy(p => p.Code)
                .ToList();

            return Result<List<PermissionModel>>.Success(modulePermissions, message: "获取模块权限列表成功。");
        }
        catch (Exception ex)
        {
            var traceId = Guid.NewGuid().ToString("N");
            _logger.LogError(ex, "获取模块权限列表失败。TraceId: {TraceId}", traceId);
            var result = Result.FromException(ex, "GET_MODULE_PERMISSIONS_FAILED", "获取模块权限列表失败。", traceId);
            return Result<List<PermissionModel>>.FailWithTrace(result.Code, result.Message, result.TraceId ?? traceId, result.Errors.ToArray());
        }
    }

    /// <inheritdoc />
    public Result<bool> CheckPermissionCodeExists(string code, Guid? excludePermissionId = null)
    {
        try
        {
            if (string.IsNullOrWhiteSpace(code))
            {
                return Result<bool>.Fail("PERMISSION_CODE_REQUIRED", "权限编码不能为空。");
            }

            var query = _permissions.Where(p => p.Code.Equals(code, StringComparison.OrdinalIgnoreCase));
            
            if (excludePermissionId.HasValue)
            {
                query = query.Where(p => p.Id != excludePermissionId.Value);
            }

            var exists = query.Any();
            return Result<bool>.Success(exists, message: exists ? "权限编码已存在" : "权限编码可用");
        }
        catch (Exception ex)
        {
            var traceId = Guid.NewGuid().ToString("N");
            _logger.LogError(ex, "检查权限编码是否存在失败。TraceId: {TraceId}", traceId);
            var result = Result.FromException(ex, "CHECK_PERMISSION_CODE_EXISTS_FAILED", "检查权限编码是否存在失败。", traceId);
            return Result<bool>.FailWithTrace(result.Code, result.Message, result.TraceId ?? traceId, result.Errors.ToArray());
        }
    }

    /// <summary>
    /// 初始化示例数据。
    /// </summary>
    private void InitializeSampleData()
    {
        var samplePermissions = new List<PermissionModel>
        {
            // 用户管理权限
            new PermissionModel
            {
                Id = Guid.NewGuid(),
                Code = "user.view",
                Name = "查看用户",
                Description = "查看用户列表和详情",
                Type = PermissionType.Function,
                Module = "user",
                Action = "view",
                Status = PermissionStatus.Enabled,
                IsSystemPermission = true,
                SortOrder = 1,
                CreatedAtUtc = DateTime.UtcNow.AddDays(-30),
                UpdatedAtUtc = DateTime.UtcNow.AddDays(-30),
                CreatedBy = "System",
                UpdatedBy = "System"
            },
            new PermissionModel
            {
                Id = Guid.NewGuid(),
                Code = "user.create",
                Name = "创建用户",
                Description = "创建新用户",
                Type = PermissionType.Function,
                Module = "user",
                Action = "create",
                Status = PermissionStatus.Enabled,
                IsSystemPermission = true,
                SortOrder = 2,
                CreatedAtUtc = DateTime.UtcNow.AddDays(-30),
                UpdatedAtUtc = DateTime.UtcNow.AddDays(-30),
                CreatedBy = "System",
                UpdatedBy = "System"
            },
            new PermissionModel
            {
                Id = Guid.NewGuid(),
                Code = "user.edit",
                Name = "编辑用户",
                Description = "编辑用户信息",
                Type = PermissionType.Function,
                Module = "user",
                Action = "edit",
                Status = PermissionStatus.Enabled,
                IsSystemPermission = true,
                SortOrder = 3,
                CreatedAtUtc = DateTime.UtcNow.AddDays(-30),
                UpdatedAtUtc = DateTime.UtcNow.AddDays(-30),
                CreatedBy = "System",
                UpdatedBy = "System"
            },
            new PermissionModel
            {
                Id = Guid.NewGuid(),
                Code = "user.delete",
                Name = "删除用户",
                Description = "删除用户",
                Type = PermissionType.Function,
                Module = "user",
                Action = "delete",
                Status = PermissionStatus.Enabled,
                IsSystemPermission = true,
                SortOrder = 4,
                CreatedAtUtc = DateTime.UtcNow.AddDays(-30),
                UpdatedAtUtc = DateTime.UtcNow.AddDays(-30),
                CreatedBy = "System",
                UpdatedBy = "System"
            },
            
            // 角色管理权限
            new PermissionModel
            {
                Id = Guid.NewGuid(),
                Code = "role.view",
                Name = "查看角色",
                Description = "查看角色列表和详情",
                Type = PermissionType.Function,
                Module = "role",
                Action = "view",
                Status = PermissionStatus.Enabled,
                IsSystemPermission = true,
                SortOrder = 1,
                CreatedAtUtc = DateTime.UtcNow.AddDays(-30),
                UpdatedAtUtc = DateTime.UtcNow.AddDays(-30),
                CreatedBy = "System",
                UpdatedBy = "System"
            },
            new PermissionModel
            {
                Id = Guid.NewGuid(),
                Code = "role.create",
                Name = "创建角色",
                Description = "创建新角色",
                Type = PermissionType.Function,
                Module = "role",
                Action = "create",
                Status = PermissionStatus.Enabled,
                IsSystemPermission = true,
                SortOrder = 2,
                CreatedAtUtc = DateTime.UtcNow.AddDays(-30),
                UpdatedAtUtc = DateTime.UtcNow.AddDays(-30),
                CreatedBy = "System",
                UpdatedBy = "System"
            },
            new PermissionModel
            {
                Id = Guid.NewGuid(),
                Code = "role.edit",
                Name = "编辑角色",
                Description = "编辑角色信息",
                Type = PermissionType.Function,
                Module = "role",
                Action = "edit",
                Status = PermissionStatus.Enabled,
                IsSystemPermission = true,
                SortOrder = 3,
                CreatedAtUtc = DateTime.UtcNow.AddDays(-30),
                UpdatedAtUtc = DateTime.UtcNow.AddDays(-30),
                CreatedBy = "System",
                UpdatedBy = "System"
            },
            new PermissionModel
            {
                Id = Guid.NewGuid(),
                Code = "role.delete",
                Name = "删除角色",
                Description = "删除角色",
                Type = PermissionType.Function,
                Module = "role",
                Action = "delete",
                Status = PermissionStatus.Enabled,
                IsSystemPermission = true,
                SortOrder = 4,
                CreatedAtUtc = DateTime.UtcNow.AddDays(-30),
                UpdatedAtUtc = DateTime.UtcNow.AddDays(-30),
                CreatedBy = "System",
                UpdatedBy = "System"
            },

            // 训练任务管理权限
            new PermissionModel
            {
                Id = Guid.NewGuid(),
                Code = "training.view",
                Name = "查看训练任务",
                Description = "查看训练任务列表和详情",
                Type = PermissionType.Function,
                Module = "training",
                Action = "view",
                Status = PermissionStatus.Enabled,
                IsSystemPermission = true,
                SortOrder = 1,
                CreatedAtUtc = DateTime.UtcNow.AddDays(-30),
                UpdatedAtUtc = DateTime.UtcNow.AddDays(-30),
                CreatedBy = "System",
                UpdatedBy = "System"
            },
            new PermissionModel
            {
                Id = Guid.NewGuid(),
                Code = "training.create",
                Name = "创建训练任务",
                Description = "创建新的训练任务",
                Type = PermissionType.Function,
                Module = "training",
                Action = "create",
                Status = PermissionStatus.Enabled,
                IsSystemPermission = true,
                SortOrder = 2,
                CreatedAtUtc = DateTime.UtcNow.AddDays(-30),
                UpdatedAtUtc = DateTime.UtcNow.AddDays(-30),
                CreatedBy = "System",
                UpdatedBy = "System"
            },
            new PermissionModel
            {
                Id = Guid.NewGuid(),
                Code = "training.start",
                Name = "启动训练任务",
                Description = "启动训练任务",
                Type = PermissionType.Function,
                Module = "training",
                Action = "start",
                Status = PermissionStatus.Enabled,
                IsSystemPermission = true,
                SortOrder = 3,
                CreatedAtUtc = DateTime.UtcNow.AddDays(-30),
                UpdatedAtUtc = DateTime.UtcNow.AddDays(-30),
                CreatedBy = "System",
                UpdatedBy = "System"
            },
            new PermissionModel
            {
                Id = Guid.NewGuid(),
                Code = "training.stop",
                Name = "停止训练任务",
                Description = "停止训练任务",
                Type = PermissionType.Function,
                Module = "training",
                Action = "stop",
                Status = PermissionStatus.Enabled,
                IsSystemPermission = true,
                SortOrder = 4,
                CreatedAtUtc = DateTime.UtcNow.AddDays(-30),
                UpdatedAtUtc = DateTime.UtcNow.AddDays(-30),
                CreatedBy = "System",
                UpdatedBy = "System"
            },

            // 系统管理权限
            new PermissionModel
            {
                Id = Guid.NewGuid(),
                Code = "system.config",
                Name = "系统配置",
                Description = "系统配置管理",
                Type = PermissionType.Function,
                Module = "system",
                Action = "config",
                Status = PermissionStatus.Enabled,
                IsSystemPermission = true,
                SortOrder = 1,
                CreatedAtUtc = DateTime.UtcNow.AddDays(-30),
                UpdatedAtUtc = DateTime.UtcNow.AddDays(-30),
                CreatedBy = "System",
                UpdatedBy = "System"
            },
            new PermissionModel
            {
                Id = Guid.NewGuid(),
                Code = "system.log",
                Name = "查看日志",
                Description = "查看系统日志",
                Type = PermissionType.Function,
                Module = "system",
                Action = "log",
                Status = PermissionStatus.Enabled,
                IsSystemPermission = true,
                SortOrder = 2,
                CreatedAtUtc = DateTime.UtcNow.AddDays(-30),
                UpdatedAtUtc = DateTime.UtcNow.AddDays(-30),
                CreatedBy = "System",
                UpdatedBy = "System"
            }
        };

        _permissions.AddRange(samplePermissions);
        _logger.LogInformation("已初始化 {Count} 个示例权限", samplePermissions.Count);
    }
}