package auth

import (
	"context"
	"errors"
	"testing"

	"perms-system-server/internal/consts"
	"perms-system-server/internal/loaders"
	"perms-system-server/internal/response"
	"perms-system-server/internal/testutil/mocks"

	"github.com/stretchr/testify/assert"
	"github.com/stretchr/testify/require"
	"github.com/zeromicro/go-zero/core/stores/sqlx"
	"go.uber.org/mock/gomock"
)

// ---------------------------------------------------------------------------
// 覆盖目标：审计 M-3 修复 —— GuardRoleLevelAssignable 必须每次走 DB 强一致查询，
// 绝不能信任 caller（loaders.UserDetails）里可能已经 stale 的 MinPermsLevel 缓存。
//
// TOCTOU 场景：
//   1. caller 原先是 permsLevel=5 的高阶成员。
//   2. 超管把 caller 的高阶角色摘掉，现在 DB 里 MinPermsLevel=100（低阶）。
//   3. UD 缓存还没被 Clean（Redis 抖动 / TTL 窗口内），caller.MinPermsLevel=5 是旧值。
//   4. caller 此刻尝试分配 permsLevel=50 的角色 —— 若信缓存（5 vs 50）会**误放行**；
//      修复后走 DB（100 vs 50），必须 403 拦截。
// ---------------------------------------------------------------------------

// TC-0930: M-3 —— stale caller.MinPermsLevel 不得影响判定，rolePermsLevel <= freshLevel 必须 403。
func TestGuardRoleLevelAssignable_StaleCallerCache_FreshDBRejects(t *testing.T) {
	ctrl := gomock.NewController(t)
	t.Cleanup(ctrl.Finish)

	const productCode = "m3_pc_stale"
	const callerId = int64(1001)

	mockRole := mocks.NewMockSysRoleModel(ctrl)
	// 关键：DB 强一致返回 100（被降级后的真实等级）。
	mockRole.EXPECT().
		FindMinPermsLevelByUserIdAndProductCode(gomock.Any(), callerId, productCode).
		Return(int64(100), nil).
		Times(1)

	svcCtx := mocks.NewMockServiceContext(mocks.MockModels{Role: mockRole})

	caller := &loaders.UserDetails{
		UserId:        callerId,
		Username:      "m3_stale_caller",
		MemberType:    consts.MemberTypeMember,
		ProductCode:   productCode,
		Status:        consts.StatusEnabled,
		MinPermsLevel: 5,
	}

	err := GuardRoleLevelAssignable(context.Background(), svcCtx, caller, 50)
	require.Error(t, err, "stale 缓存(5) 下试图分配 permsLevel=50，信缓存会放行；走 DB(100) 必须 403")

	var ce *response.CodeError
	require.True(t, errors.As(err, &ce))
	assert.Equal(t, 403, ce.Code(), "M-3：拒绝分配高于自身 fresh 等级的角色 → 403")
}

// TC-0931: M-3 —— 同级（rolePermsLevel == freshLevel）也要拦截，保持与 checkPermLevel 的 ">=" 对齐。
func TestGuardRoleLevelAssignable_SameLevel_Rejected(t *testing.T) {
	ctrl := gomock.NewController(t)
	t.Cleanup(ctrl.Finish)

	const productCode = "m3_pc_same"
	const callerId = int64(1002)

	mockRole := mocks.NewMockSysRoleModel(ctrl)
	mockRole.EXPECT().
		FindMinPermsLevelByUserIdAndProductCode(gomock.Any(), callerId, productCode).
		Return(int64(50), nil).
		Times(1)

	svcCtx := mocks.NewMockServiceContext(mocks.MockModels{Role: mockRole})

	caller := &loaders.UserDetails{
		UserId:      callerId,
		Username:    "m3_same_caller",
		MemberType:  consts.MemberTypeMember,
		ProductCode: productCode,
		Status:      consts.StatusEnabled,
	}

	err := GuardRoleLevelAssignable(context.Background(), svcCtx, caller, 50)
	require.Error(t, err, "与自身同级不允许分配，否则会让下属获得与上级等效的权力")
	var ce *response.CodeError
	require.True(t, errors.As(err, &ce))
	assert.Equal(t, 403, ce.Code())
	assert.Contains(t, ce.Error(), "同级")
}

// TC-0932: M-3 —— rolePermsLevel 严格低于 freshLevel（数值更大）时放行。
func TestGuardRoleLevelAssignable_StrictlyLower_Allowed(t *testing.T) {
	ctrl := gomock.NewController(t)
	t.Cleanup(ctrl.Finish)

	const productCode = "m3_pc_ok"
	const callerId = int64(1003)

	mockRole := mocks.NewMockSysRoleModel(ctrl)
	mockRole.EXPECT().
		FindMinPermsLevelByUserIdAndProductCode(gomock.Any(), callerId, productCode).
		Return(int64(50), nil).
		Times(1)

	svcCtx := mocks.NewMockServiceContext(mocks.MockModels{Role: mockRole})

	caller := &loaders.UserDetails{
		UserId:      callerId,
		Username:    "m3_ok_caller",
		MemberType:  consts.MemberTypeMember,
		ProductCode: productCode,
		Status:      consts.StatusEnabled,
	}

	err := GuardRoleLevelAssignable(context.Background(), svcCtx, caller, 80)
	require.NoError(t, err, "permsLevel=80 严格低于 freshLevel=50（数值更大 = 更低权限）应放行")
}

// TC-0933: M-3 —— SuperAdmin 完全豁免，不触发任何 DB 查询。
func TestGuardRoleLevelAssignable_SuperAdmin_BypassNoDBCall(t *testing.T) {
	ctrl := gomock.NewController(t)
	t.Cleanup(ctrl.Finish)

	mockRole := mocks.NewMockSysRoleModel(ctrl)
	// 预期 0 次调用：SuperAdmin 必须短路返回，不能浪费 DB RTT。
	mockRole.EXPECT().
		FindMinPermsLevelByUserIdAndProductCode(gomock.Any(), gomock.Any(), gomock.Any()).
		Times(0)

	svcCtx := mocks.NewMockServiceContext(mocks.MockModels{Role: mockRole})

	caller := &loaders.UserDetails{
		UserId: 1, Username: "root", IsSuperAdmin: true, Status: consts.StatusEnabled,
	}

	err := GuardRoleLevelAssignable(context.Background(), svcCtx, caller, 1)
	require.NoError(t, err, "SuperAdmin 必须放行任何 permsLevel")
}

// TC-0934: M-3 —— 产品 ADMIN 拥有全权，豁免 DB 查询。
func TestGuardRoleLevelAssignable_ProductAdmin_BypassNoDBCall(t *testing.T) {
	ctrl := gomock.NewController(t)
	t.Cleanup(ctrl.Finish)

	mockRole := mocks.NewMockSysRoleModel(ctrl)
	mockRole.EXPECT().
		FindMinPermsLevelByUserIdAndProductCode(gomock.Any(), gomock.Any(), gomock.Any()).
		Times(0)

	svcCtx := mocks.NewMockServiceContext(mocks.MockModels{Role: mockRole})

	caller := &loaders.UserDetails{
		UserId: 2, Username: "pa", MemberType: consts.MemberTypeAdmin,
		ProductCode: "p1", Status: consts.StatusEnabled,
	}
	err := GuardRoleLevelAssignable(context.Background(), svcCtx, caller, 1)
	require.NoError(t, err, "产品 ADMIN 属于全权角色，必须豁免等级校验")
}

// TC-0935: M-3 —— DEVELOPER 同样享有全权豁免。
func TestGuardRoleLevelAssignable_Developer_BypassNoDBCall(t *testing.T) {
	ctrl := gomock.NewController(t)
	t.Cleanup(ctrl.Finish)

	mockRole := mocks.NewMockSysRoleModel(ctrl)
	mockRole.EXPECT().
		FindMinPermsLevelByUserIdAndProductCode(gomock.Any(), gomock.Any(), gomock.Any()).
		Times(0)

	svcCtx := mocks.NewMockServiceContext(mocks.MockModels{Role: mockRole})

	caller := &loaders.UserDetails{
		UserId: 3, Username: "dev", MemberType: consts.MemberTypeDeveloper,
		ProductCode: "p1", Status: consts.StatusEnabled,
	}
	err := GuardRoleLevelAssignable(context.Background(), svcCtx, caller, 1)
	require.NoError(t, err)
}

// TC-0936: M-3 —— caller 在 DB 里**无任何角色**（ErrNotFound），必须 403，不能默认为 MaxInt64 放行。
// 这里的语义是"没有可分配的角色等级"：一个 MEMBER 连自己都没角色，自然不能分配角色给别人。
func TestGuardRoleLevelAssignable_CallerHasNoRole_Rejected(t *testing.T) {
	ctrl := gomock.NewController(t)
	t.Cleanup(ctrl.Finish)

	const productCode = "m3_pc_noRole"
	const callerId = int64(1004)

	mockRole := mocks.NewMockSysRoleModel(ctrl)
	mockRole.EXPECT().
		FindMinPermsLevelByUserIdAndProductCode(gomock.Any(), callerId, productCode).
		Return(int64(0), sqlx.ErrNotFound).
		Times(1)

	svcCtx := mocks.NewMockServiceContext(mocks.MockModels{Role: mockRole})

	caller := &loaders.UserDetails{
		UserId: callerId, Username: "m3_no_role", MemberType: consts.MemberTypeMember,
		ProductCode: productCode, Status: consts.StatusEnabled,
	}

	err := GuardRoleLevelAssignable(context.Background(), svcCtx, caller, 99)
	require.Error(t, err, "caller 无任何角色时必须拒绝，否则会被误判为 MaxInt64 最低级从而放行任何 permsLevel")
	var ce *response.CodeError
	require.True(t, errors.As(err, &ce))
	assert.Equal(t, 403, ce.Code())
	assert.Contains(t, ce.Error(), "没有可分配的角色等级")
}

// TC-0937: M-3 —— DB 抖动（非 ErrNotFound）必须 fail-close 返回 500，不得降级为"无角色 → 放行"。
func TestGuardRoleLevelAssignable_DBError_FailCloseWith500(t *testing.T) {
	ctrl := gomock.NewController(t)
	t.Cleanup(ctrl.Finish)

	const productCode = "m3_pc_dbErr"
	const callerId = int64(1005)

	mockRole := mocks.NewMockSysRoleModel(ctrl)
	mockRole.EXPECT().
		FindMinPermsLevelByUserIdAndProductCode(gomock.Any(), callerId, productCode).
		Return(int64(0), errors.New("driver: bad connection")).
		Times(1)

	svcCtx := mocks.NewMockServiceContext(mocks.MockModels{Role: mockRole})

	caller := &loaders.UserDetails{
		UserId: callerId, Username: "m3_db_err", MemberType: consts.MemberTypeMember,
		ProductCode: productCode, Status: consts.StatusEnabled,
	}

	err := GuardRoleLevelAssignable(context.Background(), svcCtx, caller, 10)
	require.Error(t, err)
	var ce *response.CodeError
	require.True(t, errors.As(err, &ce))
	assert.Equal(t, 500, ce.Code(),
		"M-3：DB 非 ErrNotFound 错误必须 fail-close 500，不能被伪装成 ErrNotFound → 放行超权分配")
}

// TC-0938: M-3 —— nil caller 防御：理论上无登录上下文绝不该进入此函数，防御性路径必须 403 而非 panic。
func TestGuardRoleLevelAssignable_NilCaller_Rejected(t *testing.T) {
	ctrl := gomock.NewController(t)
	t.Cleanup(ctrl.Finish)

	mockRole := mocks.NewMockSysRoleModel(ctrl)
	mockRole.EXPECT().
		FindMinPermsLevelByUserIdAndProductCode(gomock.Any(), gomock.Any(), gomock.Any()).
		Times(0)

	svcCtx := mocks.NewMockServiceContext(mocks.MockModels{Role: mockRole})

	err := GuardRoleLevelAssignable(context.Background(), svcCtx, nil, 10)
	require.Error(t, err, "nil caller 必须被拦截，杜绝隐式放行")
	var ce *response.CodeError
	require.True(t, errors.As(err, &ce))
	assert.Equal(t, 403, ce.Code())
}