Permify / permify

import (

	"context"

	"errors"

	"log/slog"

	"github.com/jackc/pgx/v5"

	"github.com/Masterminds/squirrel"

	"github.com/rs/xid"

	"github.com/Permify/permify/internal"

	"github.com/Permify/permify/internal/schema"

	"github.com/Permify/permify/internal/storage"

	"github.com/Permify/permify/internal/storage/postgres/utils"

	"github.com/Permify/permify/pkg/database"

	db "github.com/Permify/permify/pkg/database/postgres"

	base "github.com/Permify/permify/pkg/pb/base/v1"

)

// SchemaReader - Structure for SchemaReader

type SchemaReader struct {

	database *db.Postgres

	// options

	txOptions pgx.TxOptions

}

// NewSchemaReader - Creates a new SchemaReader

func NewSchemaReader(database *db.Postgres) *SchemaReader {

	return &SchemaReader{

		database:  database,

		txOptions: pgx.TxOptions{IsoLevel: pgx.ReadCommitted, AccessMode: pgx.ReadOnly},

	}

}

// ReadSchema returns the schema definition for a specific tenant and version as a structured object.

func (r *SchemaReader) ReadSchema(ctx context.Context, tenantID, version string) (sch *base.SchemaDefinition, err error) {

	ctx, span := internal.Tracer.Start(ctx, "schema-reader.read-schema")

	defer span.End()

	slog.DebugContext(ctx, "reading schema", slog.Any("tenant_id", tenantID), slog.Any("version", version))

	builder := r.database.Builder.Select("name, serialized_definition, version").From(SchemaDefinitionTable).Where(squirrel.Eq{"version": version, "tenant_id": tenantID})

	var query string

	var args []interface{}

	query, args, err = builder.ToSql()

	if err != nil {

		return nil, utils.HandleError(ctx, span, err, base.ErrorCode_ERROR_CODE_SQL_BUILDER)

	}

	slog.DebugContext(ctx, "executing sql query", slog.Any("query", query), slog.Any("arguments", args))

	var rows pgx.Rows

	rows, err = r.database.ReadPool.Query(ctx, query, args...)

	if err != nil {

		return nil, utils.HandleError(ctx, span, err, base.ErrorCode_ERROR_CODE_EXECUTION)

	}

	defer rows.Close()

	var definitions []string

	for rows.Next() {

		sd := storage.SchemaDefinition{}

		err = rows.Scan(&sd.Name, &sd.SerializedDefinition, &sd.Version)

		if err != nil {

			return nil, utils.HandleError(ctx, span, err, base.ErrorCode_ERROR_CODE_SCAN)

		}

		definitions = append(definitions, sd.Serialized())

	}

	if err = rows.Err(); err != nil {

		return nil, utils.HandleError(ctx, span, err, base.ErrorCode_ERROR_CODE_SCAN)

	}

	slog.DebugContext(ctx, "successfully retrieved", slog.Any("schema definitions", len(definitions)))

	sch, err = schema.NewSchemaFromStringDefinitions(false, definitions...)

	if err != nil {

		return nil, utils.HandleError(ctx, span, err, base.ErrorCode_ERROR_CODE_INTERNAL)

	}

	return sch, err

}

// ReadSchemaString returns the schema definition for a specific tenant and version as a string.

// ReadEntityDefinition - Reads entity config from the repository.

func (r *SchemaReader) ReadEntityDefinition(ctx context.Context, tenantID, name, version string) (definition *base.EntityDefinition, v string, err error) {

	ctx, span := internal.Tracer.Start(ctx, "schema-reader.read-entity-definition")

	defer span.End()

	slog.DebugContext(ctx, "reading entity definition", slog.Any("tenant_id", tenantID), slog.Any("version", version))

	builder := r.database.Builder.Select("name, serialized_definition, version").Where(squirrel.Eq{"name": name, "version": version, "tenant_id": tenantID}).From(SchemaDefinitionTable).Limit(1)

	var query string

	var args []interface{}

	query, args, err = builder.ToSql()

	if err != nil {

		return nil, "", utils.HandleError(ctx, span, err, base.ErrorCode_ERROR_CODE_SQL_BUILDER)

	}

	slog.DebugContext(ctx, "executing sql query", slog.Any("query", query), slog.Any("arguments", args))

	var def storage.SchemaDefinition

	row := r.database.ReadPool.QueryRow(ctx, query, args...)

	if err = row.Scan(&def.Name, &def.SerializedDefinition, &def.Version); err != nil {

		if errors.Is(err, pgx.ErrNoRows) {

			return nil, "", utils.HandleError(ctx, span, err, base.ErrorCode_ERROR_CODE_SCHEMA_NOT_FOUND)

		}

		return nil, "", utils.HandleError(ctx, span, err, base.ErrorCode_ERROR_CODE_SCAN)

	}

	var sch *base.SchemaDefinition

	sch, err = schema.NewSchemaFromStringDefinitions(false, def.Serialized())

	if err != nil {

		return nil, "", utils.HandleError(ctx, span, err, base.ErrorCode_ERROR_CODE_INTERNAL)

	}

	definition, err = schema.GetEntityByName(sch, name)

	slog.DebugContext(ctx, "successfully retrieved", slog.Any("schema definition", definition))

	return definition, def.Version, err

}

// ReadRuleDefinition - Reads rule config from the repository.

func (r *SchemaReader) ReadRuleDefinition(ctx context.Context, tenantID, name, version string) (definition *base.RuleDefinition, v string, err error) {

	ctx, span := internal.Tracer.Start(ctx, "schema-reader.read-rule-definition")

	defer span.End()

	slog.DebugContext(ctx, "reading rule definition", slog.Any("tenant_id", tenantID), slog.Any("name", name), slog.Any("version", version))

	builder := r.database.Builder.Select("name, serialized_definition, version").Where(squirrel.Eq{"name": name, "version": version, "tenant_id": tenantID}).From(SchemaDefinitionTable).Limit(1)

	var query string

	var args []interface{}

	query, args, err = builder.ToSql()

	if err != nil {

		return nil, "", utils.HandleError(ctx, span, err, base.ErrorCode_ERROR_CODE_SQL_BUILDER)

	}

	slog.DebugContext(ctx, "executing sql query", slog.Any("query", query), slog.Any("arguments", args))

	var def storage.SchemaDefinition

	row := r.database.ReadPool.QueryRow(ctx, query, args...)

	if err = row.Scan(&def.Name, &def.SerializedDefinition, &def.Version); err != nil {

		if errors.Is(err, pgx.ErrNoRows) {

			return nil, "", utils.HandleError(ctx, span, err, base.ErrorCode_ERROR_CODE_SCHEMA_NOT_FOUND)

		}

		return nil, "", utils.HandleError(ctx, span, err, base.ErrorCode_ERROR_CODE_SCAN)

	}

	slog.DebugContext(ctx, "successfully retrieved rule definition for", slog.Any("name", name))

	var sch *base.SchemaDefinition

	sch, err = schema.NewSchemaFromStringDefinitions(false, def.Serialized())

	if err != nil {

		return nil, "", utils.HandleError(ctx, span, err, base.ErrorCode_ERROR_CODE_INTERNAL)

	}

	definition, err = schema.GetRuleByName(sch, name)

	slog.DebugContext(ctx, "successfully created rule definition")

	return definition, def.Version, err

}

// HeadVersion - Finds the latest version of the schema.

func (r *SchemaReader) HeadVersion(ctx context.Context, tenantID string) (version string, err error) {

	ctx, span := internal.Tracer.Start(ctx, "schema-reader.head-version")

	defer span.End()

	slog.DebugContext(ctx, "finding the latest version fo the schema for", slog.String("tenant_id", tenantID))

	var query string

	var args []interface{}

	query, args, err = r.database.Builder.

		Select("version").From(SchemaDefinitionTable).Where(squirrel.Eq{"tenant_id": tenantID}).OrderBy("version DESC").Limit(1).

		ToSql()

	if err != nil {

		return "", utils.HandleError(ctx, span, err, base.ErrorCode_ERROR_CODE_SQL_BUILDER)

	}

	slog.DebugContext(ctx, "executing sql query", slog.Any("query", query), slog.Any("arguments", args))

	row := r.database.ReadPool.QueryRow(ctx, query, args...)

	err = row.Scan(&version)

	if err != nil {

		if errors.Is(err, pgx.ErrNoRows) {

			return "", utils.HandleError(ctx, span, err, base.ErrorCode_ERROR_CODE_SCHEMA_NOT_FOUND)

		}

		return "", utils.HandleError(ctx, span, err, base.ErrorCode_ERROR_CODE_SCAN)

	}

	slog.DebugContext(ctx, "successfully found the latest schema version", slog.Any("version", version))

	return version, nil

}

// ListSchemas - List all Schemas

func (r *SchemaReader) ListSchemas(ctx context.Context, tenantID string, pagination database.Pagination) (schemas []*base.SchemaList, ct database.EncodedContinuousToken, err error) {

	ctx, span := internal.Tracer.Start(ctx, "tenant-reader.list-tenants")

	defer span.End()

	slog.DebugContext(ctx, "listing schemas with pagination", slog.Any("pagination", pagination))

	builder := r.database.Builder.Select("DISTINCT version").From(SchemaDefinitionTable).Where(squirrel.Eq{"tenant_id": tenantID})

	if pagination.Token() != "" {

		var t database.ContinuousToken

		t, err = utils.EncodedContinuousToken{Value: pagination.Token()}.Decode()

		if err != nil {

			return nil, nil, utils.HandleError(ctx, span, err, base.ErrorCode_ERROR_CODE_INVALID_CONTINUOUS_TOKEN)

		}

		builder = builder.Where(squirrel.LtOrEq{"version": t.(utils.ContinuousToken).Value})

	}

	builder = builder.OrderBy("version DESC").Limit(uint64(pagination.PageSize() + 1))

	var query string

	var args []interface{}

	query, args, err = builder.ToSql()

	if err != nil {

		return nil, nil, utils.HandleError(ctx, span, err, base.ErrorCode_ERROR_CODE_SQL_BUILDER)

	}

	slog.DebugContext(ctx, "executing sql query", slog.Any("query", query), slog.Any("arguments", args))

	var rows pgx.Rows

	rows, err = r.database.ReadPool.Query(ctx, query, args...)

	if err != nil {

		return nil, nil, utils.HandleError(ctx, span, err, base.ErrorCode_ERROR_CODE_EXECUTION)

	}

	defer rows.Close()

	var lastVersion string

	schemas = make([]*base.SchemaList, 0, pagination.PageSize()+1)

	for rows.Next() {

		sch := &base.SchemaList{}

		err = rows.Scan(&sch.Version)

		if err != nil {

			return nil, nil, utils.HandleError(ctx, span, err, base.ErrorCode_ERROR_CODE_SCAN)

		}

		id, err := xid.FromString(sch.Version)

		if err != nil {

			return nil, nil, utils.HandleError(ctx, span, err, base.ErrorCode_ERROR_CODE_SCAN)

		}

		sch.CreatedAt = id.Time().String()

		lastVersion = sch.Version

		schemas = append(schemas, sch)

	}

	if err = rows.Err(); err != nil {

		return nil, nil, utils.HandleError(ctx, span, err, base.ErrorCode_ERROR_CODE_INTERNAL)

	}

	slog.DebugContext(ctx, "successfully listed schemas", slog.Any("number_of_schemas", len(schemas)))

	if len(schemas) > int(pagination.PageSize()) {

		return schemas[:pagination.PageSize()], utils.NewContinuousToken(lastVersion).Encode(), nil

	}

	return schemas, database.NewNoopContinuousToken().Encode(), nil

}