package agent

import (
	"context"
	"testing"

	mcpv1 "git.wntrmute.dev/mc/mcp/gen/mcp/v1"
	"git.wntrmute.dev/mc/mcp/internal/registry"
)

func TestPurgeComponentRemoved(t *testing.T) {
	rt := &fakeRuntime{}
	a := newTestAgent(t, rt)
	ctx := context.Background()

	// Set up a service with a stale component.
	if err := registry.CreateService(a.DB, "mcns", true); err != nil {
		t.Fatalf("create service: %v", err)
	}
	if err := registry.CreateComponent(a.DB, &registry.Component{
		Name:          "coredns",
		Service:       "mcns",
		Image:         "coredns:latest",
		DesiredState:  "running",
		ObservedState: "removed",
	}); err != nil {
		t.Fatalf("create component: %v", err)
	}

	// Insert an event for this component.
	if err := registry.InsertEvent(a.DB, "mcns", "coredns", "running", "removed"); err != nil {
		t.Fatalf("insert event: %v", err)
	}

	resp, err := a.PurgeComponent(ctx, &mcpv1.PurgeRequest{
		DefinedComponents: []string{"mcns/mcns"},
	})
	if err != nil {
		t.Fatalf("PurgeComponent: %v", err)
	}

	if len(resp.Results) != 1 {
		t.Fatalf("expected 1 result, got %d", len(resp.Results))
	}

	r := resp.Results[0]
	if !r.Purged {
		t.Fatalf("expected purged=true, got reason: %s", r.Reason)
	}
	if r.Service != "mcns" || r.Component != "coredns" {
		t.Fatalf("unexpected result: %s/%s", r.Service, r.Component)
	}

	// Verify component was deleted.
	_, err = registry.GetComponent(a.DB, "mcns", "coredns")
	if err == nil {
		t.Fatal("component should have been deleted")
	}

	// Service should also be deleted since it has no remaining components.
	_, err = registry.GetService(a.DB, "mcns")
	if err == nil {
		t.Fatal("service should have been deleted (no remaining components)")
	}
}

func TestPurgeRefusesRunning(t *testing.T) {
	rt := &fakeRuntime{}
	a := newTestAgent(t, rt)
	ctx := context.Background()

	if err := registry.CreateService(a.DB, "mcr", true); err != nil {
		t.Fatalf("create service: %v", err)
	}
	if err := registry.CreateComponent(a.DB, &registry.Component{
		Name:          "api",
		Service:       "mcr",
		Image:         "mcr:latest",
		DesiredState:  "running",
		ObservedState: "running",
	}); err != nil {
		t.Fatalf("create component: %v", err)
	}

	resp, err := a.PurgeComponent(ctx, &mcpv1.PurgeRequest{
		Service:   "mcr",
		Component: "api",
	})
	if err != nil {
		t.Fatalf("PurgeComponent: %v", err)
	}

	if len(resp.Results) != 1 {
		t.Fatalf("expected 1 result, got %d", len(resp.Results))
	}
	if resp.Results[0].Purged {
		t.Fatal("should not purge a running component")
	}

	// Verify component still exists.
	_, err = registry.GetComponent(a.DB, "mcr", "api")
	if err != nil {
		t.Fatalf("component should still exist: %v", err)
	}
}

func TestPurgeRefusesStopped(t *testing.T) {
	rt := &fakeRuntime{}
	a := newTestAgent(t, rt)
	ctx := context.Background()

	if err := registry.CreateService(a.DB, "mcr", true); err != nil {
		t.Fatalf("create service: %v", err)
	}
	if err := registry.CreateComponent(a.DB, &registry.Component{
		Name:          "api",
		Service:       "mcr",
		Image:         "mcr:latest",
		DesiredState:  "stopped",
		ObservedState: "stopped",
	}); err != nil {
		t.Fatalf("create component: %v", err)
	}

	resp, err := a.PurgeComponent(ctx, &mcpv1.PurgeRequest{
		Service:   "mcr",
		Component: "api",
	})
	if err != nil {
		t.Fatalf("PurgeComponent: %v", err)
	}

	if resp.Results[0].Purged {
		t.Fatal("should not purge a stopped component")
	}
}

func TestPurgeSkipsDefinedComponent(t *testing.T) {
	rt := &fakeRuntime{}
	a := newTestAgent(t, rt)
	ctx := context.Background()

	if err := registry.CreateService(a.DB, "mcns", true); err != nil {
		t.Fatalf("create service: %v", err)
	}
	if err := registry.CreateComponent(a.DB, &registry.Component{
		Name:          "mcns",
		Service:       "mcns",
		Image:         "mcns:latest",
		DesiredState:  "running",
		ObservedState: "exited",
	}); err != nil {
		t.Fatalf("create component: %v", err)
	}

	resp, err := a.PurgeComponent(ctx, &mcpv1.PurgeRequest{
		DefinedComponents: []string{"mcns/mcns"},
	})
	if err != nil {
		t.Fatalf("PurgeComponent: %v", err)
	}

	if len(resp.Results) != 1 {
		t.Fatalf("expected 1 result, got %d", len(resp.Results))
	}
	if resp.Results[0].Purged {
		t.Fatal("should not purge a component that is still in service definitions")
	}
	if resp.Results[0].Reason != "still in service definitions" {
		t.Fatalf("unexpected reason: %s", resp.Results[0].Reason)
	}
}

func TestPurgeDryRun(t *testing.T) {
	rt := &fakeRuntime{}
	a := newTestAgent(t, rt)
	ctx := context.Background()

	if err := registry.CreateService(a.DB, "mcns", true); err != nil {
		t.Fatalf("create service: %v", err)
	}
	if err := registry.CreateComponent(a.DB, &registry.Component{
		Name:          "coredns",
		Service:       "mcns",
		Image:         "coredns:latest",
		DesiredState:  "running",
		ObservedState: "removed",
	}); err != nil {
		t.Fatalf("create component: %v", err)
	}

	resp, err := a.PurgeComponent(ctx, &mcpv1.PurgeRequest{
		DryRun:            true,
		DefinedComponents: []string{"mcns/mcns"},
	})
	if err != nil {
		t.Fatalf("PurgeComponent: %v", err)
	}

	if len(resp.Results) != 1 {
		t.Fatalf("expected 1 result, got %d", len(resp.Results))
	}
	if !resp.Results[0].Purged {
		t.Fatal("dry run should report purged=true for eligible components")
	}

	// Verify component was NOT deleted (dry run).
	_, err = registry.GetComponent(a.DB, "mcns", "coredns")
	if err != nil {
		t.Fatalf("component should still exist after dry run: %v", err)
	}
}

func TestPurgeServiceFilter(t *testing.T) {
	rt := &fakeRuntime{}
	a := newTestAgent(t, rt)
	ctx := context.Background()

	// Create two services.
	if err := registry.CreateService(a.DB, "mcns", true); err != nil {
		t.Fatalf("create service: %v", err)
	}
	if err := registry.CreateComponent(a.DB, &registry.Component{
		Name: "coredns", Service: "mcns", Image: "coredns:latest",
		DesiredState: "running", ObservedState: "removed",
	}); err != nil {
		t.Fatalf("create component: %v", err)
	}
	if err := registry.CreateService(a.DB, "mcr", true); err != nil {
		t.Fatalf("create service: %v", err)
	}
	if err := registry.CreateComponent(a.DB, &registry.Component{
		Name: "old", Service: "mcr", Image: "old:latest",
		DesiredState: "running", ObservedState: "removed",
	}); err != nil {
		t.Fatalf("create component: %v", err)
	}

	// Purge only mcns.
	resp, err := a.PurgeComponent(ctx, &mcpv1.PurgeRequest{
		Service: "mcns",
	})
	if err != nil {
		t.Fatalf("PurgeComponent: %v", err)
	}

	if len(resp.Results) != 1 {
		t.Fatalf("expected 1 result, got %d", len(resp.Results))
	}
	if resp.Results[0].Service != "mcns" {
		t.Fatalf("expected mcns, got %s", resp.Results[0].Service)
	}

	// mcr/old should still exist.
	_, err = registry.GetComponent(a.DB, "mcr", "old")
	if err != nil {
		t.Fatalf("mcr/old should still exist: %v", err)
	}
}

func TestPurgeServiceDeletedWhenEmpty(t *testing.T) {
	rt := &fakeRuntime{}
	a := newTestAgent(t, rt)
	ctx := context.Background()

	if err := registry.CreateService(a.DB, "mcns", true); err != nil {
		t.Fatalf("create service: %v", err)
	}
	if err := registry.CreateComponent(a.DB, &registry.Component{
		Name: "coredns", Service: "mcns", Image: "coredns:latest",
		DesiredState: "running", ObservedState: "removed",
	}); err != nil {
		t.Fatalf("create component: %v", err)
	}
	if err := registry.CreateComponent(a.DB, &registry.Component{
		Name: "old-thing", Service: "mcns", Image: "old:latest",
		DesiredState: "stopped", ObservedState: "unknown",
	}); err != nil {
		t.Fatalf("create component: %v", err)
	}

	resp, err := a.PurgeComponent(ctx, &mcpv1.PurgeRequest{})
	if err != nil {
		t.Fatalf("PurgeComponent: %v", err)
	}

	// Both components should be purged.
	if len(resp.Results) != 2 {
		t.Fatalf("expected 2 results, got %d", len(resp.Results))
	}
	for _, r := range resp.Results {
		if !r.Purged {
			t.Fatalf("expected purged=true for %s/%s: %s", r.Service, r.Component, r.Reason)
		}
	}

	// Service should be deleted.
	_, err = registry.GetService(a.DB, "mcns")
	if err == nil {
		t.Fatal("service should have been deleted")
	}
}

func TestPurgeServiceKeptWhenComponentsRemain(t *testing.T) {
	rt := &fakeRuntime{}
	a := newTestAgent(t, rt)
	ctx := context.Background()

	if err := registry.CreateService(a.DB, "mcns", true); err != nil {
		t.Fatalf("create service: %v", err)
	}
	// Stale component (will be purged).
	if err := registry.CreateComponent(a.DB, &registry.Component{
		Name: "coredns", Service: "mcns", Image: "coredns:latest",
		DesiredState: "running", ObservedState: "removed",
	}); err != nil {
		t.Fatalf("create component: %v", err)
	}
	// Live component (will not be purged).
	if err := registry.CreateComponent(a.DB, &registry.Component{
		Name: "mcns", Service: "mcns", Image: "mcns:latest",
		DesiredState: "running", ObservedState: "running",
	}); err != nil {
		t.Fatalf("create component: %v", err)
	}

	resp, err := a.PurgeComponent(ctx, &mcpv1.PurgeRequest{})
	if err != nil {
		t.Fatalf("PurgeComponent: %v", err)
	}

	if len(resp.Results) != 2 {
		t.Fatalf("expected 2 results, got %d", len(resp.Results))
	}

	// coredns should be purged, mcns should not.
	purged := 0
	for _, r := range resp.Results {
		if r.Purged {
			purged++
			if r.Component != "coredns" {
				t.Fatalf("expected coredns to be purged, got %s", r.Component)
			}
		}
	}
	if purged != 1 {
		t.Fatalf("expected 1 purged, got %d", purged)
	}

	// Service should still exist.
	_, err = registry.GetService(a.DB, "mcns")
	if err != nil {
		t.Fatalf("service should still exist: %v", err)
	}
}

func TestPurgeExitedState(t *testing.T) {
	rt := &fakeRuntime{}
	a := newTestAgent(t, rt)
	ctx := context.Background()

	if err := registry.CreateService(a.DB, "test", true); err != nil {
		t.Fatalf("create service: %v", err)
	}
	if err := registry.CreateComponent(a.DB, &registry.Component{
		Name: "old", Service: "test", Image: "old:latest",
		DesiredState: "stopped", ObservedState: "exited",
	}); err != nil {
		t.Fatalf("create component: %v", err)
	}

	resp, err := a.PurgeComponent(ctx, &mcpv1.PurgeRequest{})
	if err != nil {
		t.Fatalf("PurgeComponent: %v", err)
	}

	if len(resp.Results) != 1 || !resp.Results[0].Purged {
		t.Fatalf("exited component should be purgeable")
	}
}

func TestPurgeUnknownState(t *testing.T) {
	rt := &fakeRuntime{}
	a := newTestAgent(t, rt)
	ctx := context.Background()

	if err := registry.CreateService(a.DB, "test", true); err != nil {
		t.Fatalf("create service: %v", err)
	}
	if err := registry.CreateComponent(a.DB, &registry.Component{
		Name: "ghost", Service: "test", Image: "ghost:latest",
		DesiredState: "running", ObservedState: "unknown",
	}); err != nil {
		t.Fatalf("create component: %v", err)
	}

	resp, err := a.PurgeComponent(ctx, &mcpv1.PurgeRequest{})
	if err != nil {
		t.Fatalf("PurgeComponent: %v", err)
	}

	if len(resp.Results) != 1 || !resp.Results[0].Purged {
		t.Fatalf("unknown component should be purgeable")
	}
}