package postgres

import (
	"database/sql"
	"fmt"

	"github.com/seaweedfs/seaweedfs/weed/credential"
	"github.com/seaweedfs/seaweedfs/weed/glog"
	"github.com/seaweedfs/seaweedfs/weed/util"
	"github.com/seaweedfs/seaweedfs/weed/util/pgxutil"
)

const (
	defaultMaxOpenConns        = 25
	defaultMaxIdleConns        = 5
	defaultConnMaxLifetimeSecs = 300
)

// jsonbParam adapts JSON bytes for an ExecContext call against a JSONB
// column. Returns nil (so the driver writes SQL NULL) when b is nil or
// empty; otherwise returns string(b) so pgx drives it as JSONB text — []byte
// would be encoded as bytea under simple_protocol (pgbouncer mode) and
// rejected by Postgres with "invalid input syntax for type json".
func jsonbParam(b []byte) interface{} {
	if len(b) == 0 {
		return nil
	}
	return string(b)
}

func init() {
	credential.Stores = append(credential.Stores, &PostgresStore{})
}

// PostgresStore implements CredentialStore using PostgreSQL
type PostgresStore struct {
	db         *sql.DB
	configured bool
}

func (store *PostgresStore) GetName() credential.CredentialStoreTypeName {
	return credential.StoreTypePostgres
}

func (store *PostgresStore) Initialize(configuration util.Configuration, prefix string) error {
	if store.configured {
		return nil
	}

	hostname := configuration.GetString(prefix + "hostname")
	port := configuration.GetInt(prefix + "port")
	username := configuration.GetString(prefix + "username")
	password := configuration.GetString(prefix + "password")
	database := configuration.GetString(prefix + "database")
	schema := configuration.GetString(prefix + "schema")
	sslmode := configuration.GetString(prefix + "sslmode")
	sslcert := configuration.GetString(prefix + "sslcert")
	sslkey := configuration.GetString(prefix + "sslkey")
	sslrootcert := configuration.GetString(prefix + "sslrootcert")
	sslcrl := configuration.GetString(prefix + "sslcrl")
	pgbouncerCompatible := configuration.GetBool(prefix + "pgbouncer_compatible")
	maxIdle := configuration.GetInt(prefix + "connection_max_idle")
	maxOpen := configuration.GetInt(prefix + "connection_max_open")
	maxLifetimeSeconds := configuration.GetInt(prefix + "connection_max_lifetime_seconds")

	if hostname == "" {
		hostname = "localhost"
	}
	if port == 0 {
		port = 5432
	}
	if sslmode == "" {
		sslmode = "disable"
	}
	if maxOpen == 0 {
		maxOpen = defaultMaxOpenConns
	}
	if maxIdle == 0 {
		maxIdle = defaultMaxIdleConns
	}
	if maxLifetimeSeconds == 0 {
		maxLifetimeSeconds = defaultConnMaxLifetimeSecs
	}

	glog.V(0).Infof("credential postgres: initializing store host=%s port=%d user=%s db=%s sslmode=%s pgbouncer=%v",
		hostname, port, username, database, sslmode, pgbouncerCompatible)

	dsn, adaptedDSN := pgxutil.BuildDSN(pgxutil.DSNOptions{
		Hostname:            hostname,
		Port:                port,
		User:                username,
		Password:            password,
		Database:            database,
		Schema:              schema,
		SSLMode:             sslmode,
		SSLCert:             sslcert,
		SSLKey:              sslkey,
		SSLRootCert:         sslrootcert,
		SSLCRL:              sslcrl,
		PgBouncerCompatible: pgbouncerCompatible,
	})

	db, err := pgxutil.OpenDB(dsn, adaptedDSN, pgbouncerCompatible, maxIdle, maxOpen, maxLifetimeSeconds)
	if err != nil {
		glog.Errorf("credential postgres: failed to open database: %v", err)
		return fmt.Errorf("failed to open database: %w", err)
	}

	glog.V(0).Infof("credential postgres: connection established")

	store.db = db

	if err := store.createTables(); err != nil {
		db.Close()
		store.db = nil
		glog.Errorf("credential postgres: failed to create tables: %v", err)
		return fmt.Errorf("failed to create tables: %w", err)
	}

	glog.V(0).Infof("credential postgres: tables verified, store ready")

	store.configured = true
	return nil
}

func (store *PostgresStore) createTables() error {
	usersTable := `
		CREATE TABLE IF NOT EXISTS users (
			username VARCHAR(255) PRIMARY KEY,
			email VARCHAR(255),
			account_data JSONB,
			actions JSONB,
			policy_names JSONB DEFAULT '[]',
			created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
			updated_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP
		);
		CREATE INDEX IF NOT EXISTS idx_users_email ON users(email);
	`

	addPolicyNamesColumn := `
		ALTER TABLE users ADD COLUMN IF NOT EXISTS policy_names JSONB DEFAULT '[]';
	`

	credentialsTable := `
		CREATE TABLE IF NOT EXISTS credentials (
			id SERIAL PRIMARY KEY,
			username VARCHAR(255) REFERENCES users(username) ON DELETE CASCADE,
			access_key VARCHAR(255) UNIQUE NOT NULL,
			secret_key VARCHAR(255) NOT NULL,
			created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP
		);
		CREATE INDEX IF NOT EXISTS idx_credentials_username ON credentials(username);
		CREATE INDEX IF NOT EXISTS idx_credentials_access_key ON credentials(access_key);
	`

	policiesTable := `
		CREATE TABLE IF NOT EXISTS policies (
			name VARCHAR(255) PRIMARY KEY,
			document JSONB NOT NULL,
			created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
			updated_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP
		);
		CREATE INDEX IF NOT EXISTS idx_policies_name ON policies(name);
	`

	serviceAccountsTable := `
		CREATE TABLE IF NOT EXISTS service_accounts (
			id VARCHAR(255) PRIMARY KEY,
			access_key VARCHAR(255) UNIQUE,
			content JSONB NOT NULL,
			created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
			updated_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP
		);
	`

	inlinePoliciesTable := `
		CREATE TABLE IF NOT EXISTS user_inline_policies (
			username VARCHAR(255) REFERENCES users(username) ON DELETE CASCADE,
			policy_name VARCHAR(255) NOT NULL,
			document JSONB NOT NULL,
			created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
			updated_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
			PRIMARY KEY (username, policy_name)
		);
		CREATE INDEX IF NOT EXISTS idx_user_inline_policies_username ON user_inline_policies(username);
	`

	groupsTable := `
		CREATE TABLE IF NOT EXISTS groups (
			name VARCHAR(255) PRIMARY KEY,
			members JSONB DEFAULT '[]',
			policy_names JSONB DEFAULT '[]',
			disabled BOOLEAN DEFAULT FALSE,
			created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
			updated_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP
		);
	`

	groupInlinePoliciesTable := `
		CREATE TABLE IF NOT EXISTS group_inline_policies (
			group_name VARCHAR(255) REFERENCES groups(name) ON DELETE CASCADE,
			policy_name VARCHAR(255) NOT NULL,
			document JSONB NOT NULL,
			created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
			updated_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
			PRIMARY KEY (group_name, policy_name)
		);
		CREATE INDEX IF NOT EXISTS idx_group_inline_policies_group_name ON group_inline_policies(group_name);
	`

	if _, err := store.db.Exec(usersTable); err != nil {
		return fmt.Errorf("failed to create users table: %w", err)
	}

	if _, err := store.db.Exec(addPolicyNamesColumn); err != nil {
		return fmt.Errorf("failed to add policy_names column: %w", err)
	}

	if _, err := store.db.Exec(credentialsTable); err != nil {
		return fmt.Errorf("failed to create credentials table: %w", err)
	}

	if _, err := store.db.Exec(policiesTable); err != nil {
		return fmt.Errorf("failed to create policies table: %w", err)
	}

	if _, err := store.db.Exec(serviceAccountsTable); err != nil {
		return fmt.Errorf("failed to create service_accounts table: %w", err)
	}

	if _, err := store.db.Exec(inlinePoliciesTable); err != nil {
		return fmt.Errorf("failed to create user_inline_policies table: %w", err)
	}

	if _, err := store.db.Exec(groupsTable); err != nil {
		return fmt.Errorf("failed to create groups table: %w", err)
	}

	if _, err := store.db.Exec(groupInlinePoliciesTable); err != nil {
		return fmt.Errorf("failed to create group_inline_policies table: %w", err)
	}

	groupsDisabledIndex := `CREATE INDEX IF NOT EXISTS idx_groups_disabled ON groups (disabled);`
	if _, err := store.db.Exec(groupsDisabledIndex); err != nil {
		return fmt.Errorf("failed to create groups disabled index: %w", err)
	}

	groupsMembersIndex := `CREATE INDEX IF NOT EXISTS idx_groups_members_gin ON groups USING GIN (members);`
	if _, err := store.db.Exec(groupsMembersIndex); err != nil {
		return fmt.Errorf("failed to create groups members index: %w", err)
	}

	return nil
}

func (store *PostgresStore) Shutdown() {
	if store.db != nil {
		glog.V(0).Infof("credential postgres: shutting down")
		store.db.Close()
		store.db = nil
	}
	store.configured = false
}