package postgresadmin

import (
	"context"
	"errors"
	"regexp"
	"sort"
	"strings"
	"testing"

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

func TestApplyMigrationsValidatesContextAndPool(t *testing.T) {
	t.Parallel()

	if err := ApplyMigrations(context.Background(), nil); !errors.Is(err, adminstate.ErrInvalidCommand) {
		t.Fatalf("ApplyMigrations(nil) error = %v, want ErrInvalidCommand", err)
	}
	ctx, cancel := context.WithCancel(context.Background())
	cancel()
	if err := ApplyMigrations(ctx, nil); !errors.Is(err, context.Canceled) {
		t.Fatalf("ApplyMigrations(canceled) error = %v, want context.Canceled", err)
	}
}

func TestMigrationsAreOrderedTransactionalAndImmutable(t *testing.T) {
	t.Parallel()
	migrations := Migrations()
	if len(migrations) != 2 {
		t.Fatalf("len(Migrations()) = %d, want 2", len(migrations))
	}
	if migrations[0].Version != 1 || migrations[0].Name != "admin_state" ||
		migrations[1].Version != 2 || migrations[1].Name != "disable_routing" {
		t.Fatalf("migration metadata = %+v", migrations)
	}
	for _, migration := range migrations {
		normalized := strings.TrimSpace(migration.SQL)
		if !strings.HasPrefix(normalized, "BEGIN;") || !strings.HasSuffix(normalized, "COMMIT;") {
			t.Fatalf("migration %d is not transaction wrapped: %q", migration.Version, normalized)
		}
	}
	for index := 1; index < len(migrations); index++ {
		if migrations[index-1].Version >= migrations[index].Version {
			t.Fatalf("migration versions are not strictly increasing: %+v", migrations)
		}
	}

	migrations[0].SQL = "changed"
	if Migrations()[0].SQL == "changed" {
		t.Fatal("Migrations() returned mutable package storage")
	}
}

func TestRoutingDisableMigrationExtendsOnlyAuditActionConstraint(t *testing.T) {
	t.Parallel()
	lower := strings.ToLower(Migrations()[1].SQL)
	for _, required := range []string{
		"alter table admin_audit_log",
		"drop constraint if exists admin_audit_log_action_check",
		"disable_routing",
	} {
		if !strings.Contains(lower, required) {
			t.Errorf("routing disable migration missing %q", required)
		}
	}
	for _, forbidden := range []string{"create table", "proxy", "credential", "extraction", "ownership", "idempotency"} {
		if strings.Contains(lower, forbidden) {
			t.Errorf("routing disable migration contains forbidden identifier %q", forbidden)
		}
	}
}

func TestAdminSchemaContainsOnlyManagementTables(t *testing.T) {
	t.Parallel()
	sql := Migrations()[0].SQL
	tablePattern := regexp.MustCompile(`(?im)^CREATE TABLE IF NOT EXISTS ([a-z][a-z0-9_]*)\s*\(`)
	matches := tablePattern.FindAllStringSubmatch(sql, -1)
	tables := make([]string, 0, len(matches))
	for _, match := range matches {
		tables = append(tables, match[1])
	}
	sort.Strings(tables)
	want := []string{
		"admin_audit_log",
		"admin_outbox",
		"config_revisions",
		"control_revisions",
		"routing_admin_state",
		"upstream_admin_state",
	}
	if strings.Join(tables, ",") != strings.Join(want, ",") {
		t.Fatalf("created tables = %v, want %v", tables, want)
	}

	lower := strings.ToLower(sql)
	for _, forbidden := range []string{
		"proxy_id", "proxy_host", "proxy_port", "credential", "password",
		"extraction_record", "ownership", "idempotency",
	} {
		if strings.Contains(lower, forbidden) {
			t.Errorf("migration contains forbidden detail identifier %q", forbidden)
		}
	}
	for _, destructive := range []string{"drop table", "truncate ", "delete from"} {
		if strings.Contains(lower, destructive) {
			t.Errorf("forward migration contains destructive statement %q", destructive)
		}
	}
}

func TestAdminSchemaContainsTransactionAndOutboxConstraints(t *testing.T) {
	t.Parallel()
	lower := strings.ToLower(Migrations()[0].SQL)
	for _, required := range []string{
		"revision bigint generated by default as identity primary key",
		"config_version varchar(128) not null unique",
		"checksum char(64) not null",
		"upstreams text[] not null",
		"current_upstream varchar(128) not null",
		"request_id varchar(128) not null",
		"source_ip inet",
		"payload jsonb not null",
		"claim_owner varchar(128)",
		"claim_until timestamptz",
		"published_at timestamptz",
		"foreign key (revision) references control_revisions(revision)",
		"where published_at is null",
	} {
		if !strings.Contains(lower, required) {
			t.Errorf("migration missing required schema fragment %q", required)
		}
	}
}