//go:build integration

package postgresadmin

import (
	"context"
	"errors"
	"strings"
	"testing"
	"time"

	"proxy-pool/internal/domain/adminstate"
)

func TestMutationRollsBackWhenAuditInsertFails(t *testing.T) {
	fixture := newPostgresTestFixture(t)
	now := integrationNow()
	commitIntegrationConfig(t, fixture.Store, now)
	installRejectInsertTrigger(t, fixture, "admin_audit_log", "reject_admin_audit")

	_, err := fixture.Store.SetUpstreamEnabled(context.Background(), adminstate.SetUpstreamCommand{
		RequestID: "req-audit-failure", Actor: integrationActor(), OccurredAt: now.Add(time.Second),
		Name: "provider-a", Enabled: false,
	})
	if !errors.Is(err, adminstate.ErrUnavailable) {
		t.Fatalf("SetUpstreamEnabled(audit failure) error = %v, want ErrUnavailable", err)
	}
	assertFailedMutationLeftBaseline(t, fixture)

	dropRejectInsertTrigger(t, fixture, "admin_audit_log", "reject_admin_audit")
	result, err := fixture.Store.SetUpstreamEnabled(context.Background(), adminstate.SetUpstreamCommand{
		RequestID: "req-after-audit-failure", Actor: integrationActor(), OccurredAt: now.Add(2 * time.Second),
		Name: "provider-a", Enabled: false,
	})
	if err != nil || !result.Changed || result.Revision != 2 {
		t.Fatalf("SetUpstreamEnabled(after rollback) = %+v, %v", result, err)
	}
}

func TestMutationRollsBackWhenOutboxInsertFails(t *testing.T) {
	fixture := newPostgresTestFixture(t)
	now := integrationNow()
	commitIntegrationConfig(t, fixture.Store, now)
	installRejectInsertTrigger(t, fixture, "admin_outbox", "reject_admin_outbox")

	_, err := fixture.Store.SetUpstreamEnabled(context.Background(), adminstate.SetUpstreamCommand{
		RequestID: "req-outbox-failure", Actor: integrationActor(), OccurredAt: now.Add(time.Second),
		Name: "provider-a", Enabled: false,
	})
	if !errors.Is(err, adminstate.ErrUnavailable) {
		t.Fatalf("SetUpstreamEnabled(outbox failure) error = %v, want ErrUnavailable", err)
	}
	assertFailedMutationLeftBaseline(t, fixture)

	dropRejectInsertTrigger(t, fixture, "admin_outbox", "reject_admin_outbox")
	result, err := fixture.Store.SetUpstreamEnabled(context.Background(), adminstate.SetUpstreamCommand{
		RequestID: "req-after-outbox-failure", Actor: integrationActor(), OccurredAt: now.Add(2 * time.Second),
		Name: "provider-a", Enabled: false,
	})
	if err != nil || !result.Changed || result.Revision != 2 {
		t.Fatalf("SetUpstreamEnabled(after rollback) = %+v, %v", result, err)
	}
}

func assertFailedMutationLeftBaseline(t *testing.T, fixture postgresTestFixture) {
	t.Helper()
	snapshot, err := fixture.Store.Snapshot(context.Background())
	if err != nil || snapshot.Revision != 1 || !integrationUpstreamEnabled(snapshot, "provider-a") {
		t.Fatalf("Snapshot(after failed mutation) = %+v, %v", snapshot, err)
	}
	audits, err := fixture.Store.ReadAudit(context.Background(), adminstate.AuditQuery{Limit: 10})
	if err != nil || len(audits) != 1 {
		t.Fatalf("ReadAudit(after failed mutation) = %+v, %v", audits, err)
	}
	for table, want := range map[string]int{"control_revisions": 1, "admin_outbox": 1} {
		var count int
		if err := fixture.Pool.QueryRow(context.Background(), "SELECT COUNT(*) FROM "+table).Scan(&count); err != nil {
			t.Fatalf("count %s: %v", table, err)
		}
		if count != want {
			t.Fatalf("%s row count = %d, want %d", table, count, want)
		}
	}
}

func installRejectInsertTrigger(t *testing.T, fixture postgresTestFixture, table, trigger string) {
	t.Helper()
	function := trigger + "_fn"
	statement := "CREATE FUNCTION " + function + `() RETURNS trigger LANGUAGE plpgsql AS $$
		BEGIN RAISE EXCEPTION 'injected management write failure'; END
	$$;
	CREATE TRIGGER ` + trigger + " BEFORE INSERT ON " + table +
		" FOR EACH ROW EXECUTE FUNCTION " + function + "()"
	if _, err := fixture.Pool.Exec(context.Background(), statement); err != nil {
		t.Fatalf("install %s trigger: %v", trigger, err)
	}
}

func dropRejectInsertTrigger(t *testing.T, fixture postgresTestFixture, table, trigger string) {
	t.Helper()
	statement := "DROP TRIGGER " + trigger + " ON " + table + "; DROP FUNCTION " + trigger + "_fn()"
	if _, err := fixture.Pool.Exec(context.Background(), statement); err != nil {
		t.Fatalf("drop %s trigger: %v", trigger, err)
	}
}

func commitIntegrationConfig(t *testing.T, store adminstate.Store, now time.Time) {
	t.Helper()
	result, err := store.CommitConfig(context.Background(), adminstate.CommitConfigCommand{
		RequestID: "req-config", Actor: integrationActor(), OccurredAt: now,
		ConfigVersion: "cfg-1", Checksum: strings.Repeat("a", adminstate.SHA256HexBytes),
		Source: "configs/proxy-pool.yaml",
		Upstreams: []adminstate.UpstreamDefinition{
			{Name: "provider-a", Enabled: true},
			{Name: "provider-b", Enabled: true},
		},
		Routings: []adminstate.RoutingDefinition{{
			Name: "checkout", Enabled: true, Upstreams: []string{"provider-a", "provider-b"},
			CurrentUpstream: "provider-a",
		}},
	})
	if err != nil || !result.Changed || result.Revision != 1 {
		t.Fatalf("CommitConfig() = %+v, %v", result, err)
	}
}

func integrationActor() adminstate.Actor {
	return adminstate.Actor{ID: "admin-a", SourceIP: "192.0.2.10"}
}

func integrationNow() time.Time {
	return time.Date(2026, 7, 30, 10, 0, 0, 0, time.UTC)
}

func integrationUpstreamEnabled(snapshot adminstate.Snapshot, name string) bool {
	for _, upstream := range snapshot.Upstreams {
		if upstream.Name == name {
			return upstream.Enabled
		}
	}
	return false
}