package worker

import (
	"context"
	"database/sql"
	"encoding/json"
	"fmt"
	"log/slog"
	"testing"
	"time"

	"github.com/fleetdm/fleet/v4/server/datastore/mysql/mysqltest"
	"github.com/fleetdm/fleet/v4/server/fleet"
	"github.com/fleetdm/fleet/v4/server/mdm/android"
	"github.com/fleetdm/fleet/v4/server/mock"
	"github.com/fleetdm/fleet/v4/server/ptr"
	"github.com/stretchr/testify/assert"
	"github.com/stretchr/testify/require"
	"google.golang.org/api/androidmanagement/v1"
)

func TestSoftwareWorker(t *testing.T) {
	ds := mysqltest.CreateMySQLDS(t)
	// call TruncateTables immediately as some DB migrations may create jobs
	mysqltest.TruncateTables(t, ds)

	mysqltest.SetTestABMAssets(t, ds, "fleet")
}

// mockAndroidModule is a mock implementation of the android.Service interface for testing.
type mockAndroidModule struct {
	android.Service

	buildFleetAgentApplicationPolicyFunc func(ctx context.Context, hostUUID string) (*androidmanagement.ApplicationPolicy, error)
	setAppsForAndroidPolicyFunc          func(ctx context.Context, enterpriseName string, appPolicies []*androidmanagement.ApplicationPolicy, hostUUIDs map[string]string) error
	addAppsToAndroidPolicyFunc           func(ctx context.Context, enterpriseName string, appPolicies []*androidmanagement.ApplicationPolicy, hostUUIDs map[string]string) (map[string]*android.MDMAndroidPolicyRequest, error)
}

func (m *mockAndroidModule) BuildFleetAgentApplicationPolicy(ctx context.Context, hostUUID string) (*androidmanagement.ApplicationPolicy, error) {
	if m.buildFleetAgentApplicationPolicyFunc != nil {
		return m.buildFleetAgentApplicationPolicyFunc(ctx, hostUUID)
	}
	return nil, nil
}

func (m *mockAndroidModule) AddAppsToAndroidPolicy(ctx context.Context, enterpriseName string, appPolicies []*androidmanagement.ApplicationPolicy, hostUUIDs map[string]string) (map[string]*android.MDMAndroidPolicyRequest, error) {
	if m.addAppsToAndroidPolicyFunc != nil {
		return m.addAppsToAndroidPolicyFunc(ctx, enterpriseName, appPolicies, hostUUIDs)
	}
	return nil, nil
}

func (m *mockAndroidModule) SetAppsForAndroidPolicy(ctx context.Context, enterpriseName string, appPolicies []*androidmanagement.ApplicationPolicy, hostUUIDs map[string]string) error {
	if m.setAppsForAndroidPolicyFunc != nil {
		return m.setAppsForAndroidPolicyFunc(ctx, enterpriseName, appPolicies, hostUUIDs)
	}
	return nil
}

// TestBulkSetAndroidAppsAvailableForHostsPreservesFleetAgent verifies that the Fleet Agent
// is preserved when an Android host is transferred between teams. This prevents the agent
// from being uninstalled (and losing state) during team transfers.
func TestBulkSetAndroidAppsAvailableForHostsPreservesFleetAgent(t *testing.T) {
	ctx := t.Context()
	hostUUID := "test-host-uuid"
	hostID := uint(1)
	teamID := uint(2)

	ds := new(mock.Store)
	ds.AndroidHostLiteByHostUUIDFunc = func(ctx context.Context, uuid string) (*fleet.AndroidHost, error) {
		return &fleet.AndroidHost{
			Host: &fleet.Host{
				ID:     hostID,
				UUID:   hostUUID,
				TeamID: ptr.Uint(teamID),
			},
		}, nil
	}
	ds.SetHostCertificateTemplatesToPendingRemoveForHostFunc = func(ctx context.Context, hostUUID string) error {
		return nil
	}
	ds.CreatePendingCertificateTemplatesForNewHostFunc = func(ctx context.Context, hostUUID string, teamID uint) (int64, error) {
		return 0, nil
	}
	ds.GetAndroidAppsInScopeForHostFunc = func(ctx context.Context, hostID uint) ([]string, error) {
		return []string{"com.example.teamapp"}, nil
	}
	ds.BulkGetAndroidAppConfigurationsFunc = func(ctx context.Context, appIDs []string, globalOrTeamID uint) (map[string][]byte, error) {
		return map[string][]byte{}, nil
	}

	var capturedAppPolicies []*androidmanagement.ApplicationPolicy
	androidModule := &mockAndroidModule{
		buildFleetAgentApplicationPolicyFunc: func(ctx context.Context, hostUUID string) (*androidmanagement.ApplicationPolicy, error) {
			return &androidmanagement.ApplicationPolicy{
				PackageName: "com.fleetdm.agent",
				InstallType: "FORCE_INSTALLED",
			}, nil
		},
		setAppsForAndroidPolicyFunc: func(ctx context.Context, enterpriseName string, appPolicies []*androidmanagement.ApplicationPolicy, hostUUIDs map[string]string) error {
			capturedAppPolicies = appPolicies
			return nil
		},
	}

	worker := &SoftwareWorker{
		Datastore:     ds,
		AndroidModule: androidModule,
		Log:           slog.New(slog.DiscardHandler),
	}

	err := worker.bulkSetAndroidAppsAvailableForHosts(ctx, map[string]uint{hostUUID: hostID}, "enterprises/test")
	require.NoError(t, err)

	// Verify both the team app and Fleet Agent are in the policy
	require.Len(t, capturedAppPolicies, 2, "expected team app + Fleet Agent")
	capturedPackageNames := make([]string, len(capturedAppPolicies))
	for i, policy := range capturedAppPolicies {
		capturedPackageNames[i] = policy.PackageName
	}
	require.ElementsMatch(t, []string{"com.example.teamapp", "com.fleetdm.agent"}, capturedPackageNames)
}

// TestBulkMakeAndroidAppsAvailableForHostPreservesFleetAgent verifies that the Fleet Agent
// is preserved when BatchAssociateVPPApps updates Android apps for a host.
// This is the singular version called from BatchAssociateVPPApps.
func TestBulkMakeAndroidAppsAvailableForHostPreservesFleetAgent(t *testing.T) {
	ctx := t.Context()
	hostUUID := "test-host-uuid"
	policyID := "test-policy-id"
	teamID := uint(2)

	ds := new(mock.Store)
	ds.AndroidHostLiteByHostUUIDFunc = func(ctx context.Context, uuid string) (*fleet.AndroidHost, error) {
		return &fleet.AndroidHost{
			Host: &fleet.Host{
				UUID:   hostUUID,
				TeamID: ptr.Uint(teamID),
			},
		}, nil
	}
	ds.BulkGetAndroidAppConfigurationsFunc = func(ctx context.Context, appIDs []string, globalOrTeamID uint) (map[string][]byte, error) {
		return map[string][]byte{}, nil
	}

	var capturedAppPolicies []*androidmanagement.ApplicationPolicy
	androidModule := &mockAndroidModule{
		buildFleetAgentApplicationPolicyFunc: func(ctx context.Context, hostUUID string) (*androidmanagement.ApplicationPolicy, error) {
			return &androidmanagement.ApplicationPolicy{
				PackageName: "com.fleetdm.agent",
				InstallType: "FORCE_INSTALLED",
			}, nil
		},
		setAppsForAndroidPolicyFunc: func(ctx context.Context, enterpriseName string, appPolicies []*androidmanagement.ApplicationPolicy, hostUUIDs map[string]string) error {
			capturedAppPolicies = appPolicies
			return nil
		},
	}

	worker := &SoftwareWorker{
		Datastore:     ds,
		AndroidModule: androidModule,
		Log:           slog.New(slog.DiscardHandler),
	}

	// Simulate adding a VPP app via BatchAssociateVPPApps
	applicationIDs := []string{"com.example.vppapp"}
	err := worker.bulkMakeAndroidAppsAvailableForHost(ctx, hostUUID, policyID, applicationIDs, "enterprises/test")
	require.NoError(t, err)

	// Verify both the VPP app and Fleet Agent are in the policy
	require.Len(t, capturedAppPolicies, 2, "expected VPP app + Fleet Agent")
	capturedPackageNames := make([]string, len(capturedAppPolicies))
	for i, policy := range capturedAppPolicies {
		capturedPackageNames[i] = policy.PackageName
	}
	require.ElementsMatch(t, []string{"com.example.vppapp", "com.fleetdm.agent"}, capturedPackageNames)
}

func TestSplitHostMap(t *testing.T) {
	t.Run("no batching when batchSize is 0", func(t *testing.T) {
		hosts := map[string]string{"a": "1", "b": "2", "c": "3"}
		batches := splitHostMap(hosts, 0)
		require.Len(t, batches, 1)
		require.Len(t, batches[0], 3)
	})

	t.Run("no batching when fewer than batchSize", func(t *testing.T) {
		hosts := map[string]string{"a": "1", "b": "2"}
		batches := splitHostMap(hosts, 5)
		require.Len(t, batches, 1)
		require.Len(t, batches[0], 2)
	})

	t.Run("splits into correct number of batches", func(t *testing.T) {
		hosts := make(map[string]string, 5)
		for i := range 5 {
			hosts[fmt.Sprintf("host-%d", i)] = fmt.Sprintf("policy-%d", i)
		}
		batches := splitHostMap(hosts, 2)
		require.Len(t, batches, 3) // 2 + 2 + 1

		// Verify all hosts are covered with no duplicates.
		seen := make(map[string]struct{})
		for _, batch := range batches {
			for k := range batch {
				_, dup := seen[k]
				assert.False(t, dup, "duplicate host %s", k)
				seen[k] = struct{}{}
			}
		}
		require.Len(t, seen, 5)
	})

	t.Run("exact multiple", func(t *testing.T) {
		hosts := make(map[string]string, 4)
		for i := range 4 {
			hosts[fmt.Sprintf("host-%d", i)] = fmt.Sprintf("policy-%d", i)
		}
		batches := splitHostMap(hosts, 2)
		require.Len(t, batches, 2)
		require.Len(t, batches[0], 2)
		require.Len(t, batches[1], 2)
	})
}

func TestMakeAndroidAppAvailableBatching(t *testing.T) {
	ds := new(mock.Store)

	// 5 hosts in scope
	ds.GetIncludedHostUUIDMapForAppStoreAppFunc = func(ctx context.Context, appTeamID uint) (map[string]string, error) {
		hosts := make(map[string]string, 5)
		for i := range 5 {
			hosts[fmt.Sprintf("host-%d", i)] = fmt.Sprintf("host-%d", i)
		}
		return hosts, nil
	}
	ds.GetAndroidAppConfigurationByAppTeamIDFunc = func(ctx context.Context, appTeamID uint) ([]byte, error) {
		return nil, nil // no config, no variables
	}

	var jobs []*fleet.Job
	ds.NewJobFunc = func(ctx context.Context, job *fleet.Job) (*fleet.Job, error) {
		job.ID = uint(len(jobs) + 1)
		jobs = append(jobs, job)
		return job, nil
	}

	w := &SoftwareWorker{
		Datastore:        ds,
		AndroidModule:    &mockAndroidModule{},
		Log:              slog.New(slog.DiscardHandler),
		AndroidBatchSize: 2, // batch size of 2 → 3 batches (2+2+1)
	}

	err := w.makeAndroidAppAvailable(t.Context(), "com.example.app", 1, "enterprises/test", false)
	require.NoError(t, err)

	// Phase 1 should queue 3 batch jobs (2+2+1 hosts), no AMAPI calls.
	require.Len(t, jobs, 3, "expected 3 batch jobs queued")

	// Verify staggered delays: 0s, 60s, 120s
	for i, job := range jobs {
		var args softwareWorkerArgs
		require.NoError(t, json.Unmarshal(*job.Args, &args))
		require.Equal(t, makeAndroidAppAvailableBatchTask, args.Task)
		require.Equal(t, "com.example.app", args.ApplicationID)
		require.Equal(t, "enterprises/test", args.EnterpriseName)

		if i == 0 {
			require.True(t, job.NotBefore.IsZero(), "first batch should have no delay")
		} else {
			expectedDelay := time.Duration(i) * androidSoftwareInstallStaggerInterval
			require.WithinDuration(t, time.Now().Add(expectedDelay), job.NotBefore, 5*time.Second,
				"batch %d should be delayed by %s", i, expectedDelay)
		}
	}

	// Count total hosts across all batches
	totalHosts := 0
	for _, job := range jobs {
		var args softwareWorkerArgs
		require.NoError(t, json.Unmarshal(*job.Args, &args))
		totalHosts += len(args.HostUUIDToPolicyID)
	}
	require.Equal(t, 5, totalHosts, "all 5 hosts should be distributed across batches")
}

func TestMakeAndroidAppAvailableBatchNoVars(t *testing.T) {
	var addAppsCalled bool
	var capturedHosts map[string]string

	androidModule := &mockAndroidModule{
		addAppsToAndroidPolicyFunc: func(ctx context.Context, enterpriseName string, appPolicies []*androidmanagement.ApplicationPolicy, hostUUIDs map[string]string) (map[string]*android.MDMAndroidPolicyRequest, error) {
			addAppsCalled = true
			capturedHosts = hostUUIDs
			result := make(map[string]*android.MDMAndroidPolicyRequest)
			for uuid := range hostUUIDs {
				result[uuid] = &android.MDMAndroidPolicyRequest{PolicyVersion: sql.Null[int64]{V: 42, Valid: true}}
			}
			return result, nil
		},
	}

	ds := new(mock.Store)
	ds.GetAndroidAppConfigurationByAppTeamIDFunc = func(ctx context.Context, appTeamID uint) ([]byte, error) {
		return nil, nil // no config
	}

	var pendingConfigs []string
	ds.SetAndroidAppInstallPendingApplyConfigFunc = func(ctx context.Context, hostUUID, applicationID string, policyVersion int64) error {
		pendingConfigs = append(pendingConfigs, hostUUID)
		return nil
	}

	w := &SoftwareWorker{Datastore: ds, AndroidModule: androidModule, Log: slog.New(slog.DiscardHandler)}

	hosts := map[string]string{"host-1": "host-1", "host-2": "host-2"}
	err := w.makeAndroidAppAvailableBatch(t.Context(), "com.example.app", 1, hosts, "enterprises/test", true)
	require.NoError(t, err)

	require.True(t, addAppsCalled, "should call AddAppsToAndroidPolicy")
	require.Equal(t, hosts, capturedHosts, "all hosts should be sent in one call")
	require.Len(t, pendingConfigs, 2, "appConfigChanged=true should update both hosts")
}

func TestMakeAndroidAppAvailableBatchWithVars(t *testing.T) {
	// Capture per-host AMAPI calls: host UUID → rendered managed config
	capturedConfigByHost := make(map[string]string)

	androidModule := &mockAndroidModule{
		addAppsToAndroidPolicyFunc: func(ctx context.Context, enterpriseName string, appPolicies []*androidmanagement.ApplicationPolicy, hostUUIDs map[string]string) (map[string]*android.MDMAndroidPolicyRequest, error) {
			// Each call should target exactly one host (per-host substitution)
			require.Len(t, hostUUIDs, 1)
			require.Len(t, appPolicies, 1)
			for uuid := range hostUUIDs {
				capturedConfigByHost[uuid] = string(appPolicies[0].ManagedConfiguration)
			}
			result := make(map[string]*android.MDMAndroidPolicyRequest)
			for uuid := range hostUUIDs {
				result[uuid] = &android.MDMAndroidPolicyRequest{PolicyVersion: sql.Null[int64]{V: 1, Valid: true}}
			}
			return result, nil
		},
	}

	ds := new(mock.Store)
	ds.GetAndroidAppConfigurationByAppTeamIDFunc = func(ctx context.Context, appTeamID uint) ([]byte, error) {
		return []byte(`{"managedConfiguration": {"deviceId": "$FLEET_VAR_HOST_UUID"}}`), nil
	}
	ds.ListHostsLiteByUUIDsFunc = func(ctx context.Context, filter fleet.TeamFilter, uuids []string) ([]*fleet.Host, error) {
		var hosts []*fleet.Host
		for _, uuid := range uuids {
			hosts = append(hosts, &fleet.Host{UUID: uuid, Platform: "android", HardwareSerial: "SN-" + uuid})
		}
		return hosts, nil
	}
	ds.SetAndroidAppInstallPendingApplyConfigFunc = func(ctx context.Context, hostUUID, applicationID string, policyVersion int64) error {
		return nil
	}

	w := &SoftwareWorker{Datastore: ds, AndroidModule: androidModule, Log: slog.New(slog.DiscardHandler)}

	hosts := map[string]string{"uuid-aaa": "uuid-aaa", "uuid-bbb": "uuid-bbb"}
	err := w.makeAndroidAppAvailableBatch(t.Context(), "com.example.app", 1, hosts, "enterprises/test", false)
	require.NoError(t, err)

	require.Len(t, capturedConfigByHost, 2, "should have called AMAPI for both hosts")
	require.Contains(t, capturedConfigByHost["uuid-aaa"], "uuid-aaa", "host uuid-aaa should appear in its config")
	require.NotContains(t, capturedConfigByHost["uuid-aaa"], "$FLEET_VAR_HOST_UUID")
	require.Contains(t, capturedConfigByHost["uuid-bbb"], "uuid-bbb", "host uuid-bbb should appear in its config")
	require.NotContains(t, capturedConfigByHost["uuid-bbb"], "$FLEET_VAR_HOST_UUID")
}

func TestQueueBulkSetAndroidAppsAvailableForHostsChunking(t *testing.T) {
	ds := new(mock.Store)

	var jobs []*fleet.Job
	ds.NewJobFunc = func(ctx context.Context, job *fleet.Job) (*fleet.Job, error) {
		job.ID = uint(len(jobs) + 1)
		jobs = append(jobs, job)
		return job, nil
	}

	hosts := make(map[string]uint, 5)
	for i := range 5 {
		hosts[fmt.Sprintf("host-%d", i)] = uint(i)
	}

	err := QueueBulkSetAndroidAppsAvailableForHosts(
		t.Context(), ds, slog.New(slog.DiscardHandler),
		hosts, "enterprises/test", 2, // batch size 2
	)
	require.NoError(t, err)

	// 5 hosts / batch size 2 = 3 jobs
	require.Len(t, jobs, 3)

	// First job should have no delay (not_before ≈ zero).
	assert.True(t, jobs[0].NotBefore.IsZero() || jobs[0].NotBefore.Before(time.Now()),
		"first job should be immediately available")

	// Subsequent jobs should have increasing not_before.
	for i := 1; i < len(jobs); i++ {
		assert.True(t, jobs[i].NotBefore.After(jobs[i-1].NotBefore),
			"job %d should have later not_before than job %d", i, i-1)
	}

	// Verify all hosts are covered.
	totalHosts := 0
	for _, job := range jobs {
		var args softwareWorkerArgs
		require.NoError(t, json.Unmarshal(*job.Args, &args))
		totalHosts += len(args.UUIDsToIDs)
	}
	require.Equal(t, 5, totalHosts)
}

func TestQueueMakeAndroidAppUnavailableJobChunking(t *testing.T) {
	ds := new(mock.Store)

	var jobs []*fleet.Job
	ds.NewJobFunc = func(ctx context.Context, job *fleet.Job) (*fleet.Job, error) {
		job.ID = uint(len(jobs) + 1)
		jobs = append(jobs, job)
		return job, nil
	}

	hosts := make(map[string]string, 5)
	for i := range 5 {
		hosts[fmt.Sprintf("host-%d", i)] = fmt.Sprintf("policy-%d", i)
	}

	err := QueueMakeAndroidAppUnavailableJob(
		t.Context(), ds, slog.New(slog.DiscardHandler),
		"com.example.app", hosts, "enterprises/test", 2,
	)
	require.NoError(t, err)

	// 5 hosts / batch size 2 = 3 jobs
	require.Len(t, jobs, 3)

	// Verify staggering.
	assert.True(t, jobs[0].NotBefore.IsZero() || jobs[0].NotBefore.Before(time.Now()))
	for i := 1; i < len(jobs); i++ {
		assert.True(t, jobs[i].NotBefore.After(jobs[i-1].NotBefore))
	}

	// Verify all hosts are covered.
	totalHosts := 0
	for _, job := range jobs {
		var args softwareWorkerArgs
		require.NoError(t, json.Unmarshal(*job.Args, &args))
		totalHosts += len(args.HostUUIDToPolicyID)
	}
	require.Equal(t, 5, totalHosts)
}