package store

import (
	"database/sql"
	"errors"
	"os"
	"path/filepath"
	"strings"
	"testing"
)

func TestSystemIdentityEnsureVerifySQLite(t *testing.T) {
	st, err := OpenSQLite(filepath.Join(t.TempDir(), "id.db"))
	if err != nil {
		t.Fatal(err)
	}
	defer st.Close()

	if err := st.VerifySystemIdentity("svc-a-aaaaaa", "sqlite"); !errors.Is(err, ErrSystemIdentityMissing) {
		t.Fatalf("empty verify: want missing, got %v", err)
	}
	if err := st.EnsureSystemIdentity("svc-a-aaaaaa", "sqlite"); err != nil {
		t.Fatal(err)
	}
	if err := st.EnsureSystemIdentity("svc-a-aaaaaa", "sqlite"); err != nil {
		t.Fatalf("idempotent ensure: %v", err)
	}
	if err := st.VerifySystemIdentity("svc-a-aaaaaa", "sqlite"); err != nil {
		t.Fatal(err)
	}
	if err := st.EnsureSystemIdentity("svc-b-bbbbbb", "sqlite"); !errors.Is(err, ErrSystemIdentityMismatch) {
		t.Fatalf("wrong id ensure: want mismatch, got %v", err)
	}
	if err := st.VerifySystemIdentity("svc-a-aaaaaa", "pg:other"); !errors.Is(err, ErrSystemIdentityMismatch) {
		t.Fatalf("wrong dbref verify: want mismatch, got %v", err)
	}
	row, err := st.GetSystemIdentity()
	if err != nil {
		t.Fatal(err)
	}
	if row.InstanceID != "svc-a-aaaaaa" || row.DBRef != "sqlite" {
		t.Fatalf("row=%+v", row)
	}
	if row.SchemaVersion != latestMigrationVersion() {
		t.Fatalf("schema_version=%d want %d", row.SchemaVersion, latestMigrationVersion())
	}
}

func TestSystemIdentityMigrationCreatesTable(t *testing.T) {
	st, err := OpenSQLite(filepath.Join(t.TempDir(), "mig.db"))
	if err != nil {
		t.Fatal(err)
	}
	defer st.Close()
	versions, err := st.MigrationStatus()
	if err != nil {
		t.Fatal(err)
	}
	found := false
	for _, v := range versions {
		if v == 27 {
			found = true
			break
		}
	}
	if !found {
		t.Fatalf("migration v27 not applied: %v", versions)
	}
	var name string
	if err := st.DB().QueryRow(`SELECT name FROM sqlite_master WHERE type='table' AND name='agent_system_identity'`).Scan(&name); err != nil || name != "agent_system_identity" {
		t.Fatalf("table missing: name=%q err=%v", name, err)
	}
	cols := identityColumnNames(t, st.DB())
	if cols != IdentityColumns {
		t.Fatalf("身份表列已偏离冻结契约：%s", cols)
	}
}

func TestOpenIdentityReadsFutureSchemaWithoutMigrating(t *testing.T) {
	dir := t.TempDir()
	path := filepath.Join(dir, "agent-system.db")
	raw, err := sql.Open("sqlite", "file:"+path)
	if err != nil {
		t.Fatal(err)
	}
	stmts := []string{
		`CREATE TABLE schema_migrations (version INTEGER PRIMARY KEY, name TEXT NOT NULL, applied_at TEXT NOT NULL)`,
		`INSERT INTO schema_migrations(version, name, applied_at) VALUES (99, 'future', 't')`,
		`CREATE TABLE agent_system_identity (
			instance_id TEXT NOT NULL PRIMARY KEY,
			dbref TEXT NOT NULL,
			schema_version INTEGER NOT NULL,
			created_at TEXT NOT NULL)`,
		`INSERT INTO agent_system_identity(instance_id, dbref, schema_version, created_at) VALUES ('svc-future-aaaa', 'sqlite', 99, 't')`,
	}
	for _, stmt := range stmts {
		if _, err := raw.Exec(stmt); err != nil {
			t.Fatal(err)
		}
	}
	raw.Close()
	st, err := OpenIdentity("", dir)
	if err != nil {
		t.Fatal(err)
	}
	defer st.Close()
	if err := st.VerifySystemIdentity("svc-future-aaaa", "sqlite"); err != nil {
		t.Fatal(err)
	}
	ver, err := st.SchemaVersion()
	if err != nil || ver != 99 {
		t.Fatalf("schema=%d err=%v，身份打开不得改写迁移版本", ver, err)
	}
	if cols := identityColumnNames(t, st.DB()); cols != IdentityColumns {
		t.Fatalf("列=%s", cols)
	}
}

func TestOpenIdentityMissingFileOrTable(t *testing.T) {
	dir := t.TempDir()
	if _, err := OpenIdentity("", filepath.Join(dir, "missing")); !errors.Is(err, ErrIdentityDBMissing) {
		t.Fatalf("缺文件：%v", err)
	}
	if _, err := os.Stat(filepath.Join(dir, "missing")); !os.IsNotExist(err) {
		t.Fatal("缺库时创建了目录")
	}
	path := filepath.Join(dir, "agent-system.db")
	raw, err := sql.Open("sqlite", "file:"+path)
	if err != nil {
		t.Fatal(err)
	}
	if _, err := raw.Exec(`CREATE TABLE schema_migrations (version INTEGER PRIMARY KEY, name TEXT NOT NULL, applied_at TEXT NOT NULL)`); err != nil {
		t.Fatal(err)
	}
	raw.Close()
	parent := filepath.Dir(path)
	if _, err := OpenIdentity("", parent); !errors.Is(err, ErrIdentityTableMissing) {
		t.Fatalf("缺表：%v", err)
	}
}

func identityColumnNames(t *testing.T, db *sql.DB) string {
	t.Helper()
	rows, err := db.Query(`SELECT name FROM pragma_table_info('agent_system_identity') ORDER BY cid`)
	if err != nil {
		t.Fatal(err)
	}
	defer rows.Close()
	var names []string
	for rows.Next() {
		var name string
		if err := rows.Scan(&name); err != nil {
			t.Fatal(err)
		}
		names = append(names, name)
	}
	return strings.Join(names, ",")
}