package gudusoft.gsqlparser.nodes.starrocks;

import gudusoft.gsqlparser.*;
import gudusoft.gsqlparser.nodes.*;
import gudusoft.gsqlparser.nodes.flink.TFlinkTableProperty;

/**
 * Represents the StarRocks FILES() table function for reading data from external storage.
 *
 * <p>The FILES() function allows querying data files directly from cloud storage
 * (S3, HDFS, GCS, Azure Blob, etc.) without creating external tables.</p>
 *
 * <p>Syntax:</p>
 * <pre>
 * FILES(
 *     "path" = "s3://bucket/path/*.parquet",
 *     "format" = "parquet",
 *     "aws.s3.access_key" = "xxx",
 *     "aws.s3.secret_key" = "xxx",
 *     "aws.s3.region" = "us-west-2"
 * )
 * </pre>
 *
 * <p>Example usage:</p>
 * <pre>
 * SELECT * FROM FILES(
 *     "path" = "s3://bucket/data.parquet",
 *     "format" = "parquet"
 * );
 *
 * INSERT INTO my_table SELECT * FROM FILES(...);
 * </pre>
 *
 * @see <a href="https://docs.starrocks.io/docs/sql-reference/sql-functions/table-functions/files/">StarRocks FILES Documentation</a>
 */
public class TFilesTableFunction extends TTableFunction {

    /**
     * The list of key-value properties passed to FILES().
     * Common properties include:
     * - path: The file path (S3, HDFS, local, etc.)
     * - format: File format (parquet, orc, csv, json, avro)
     * - aws.s3.access_key, aws.s3.secret_key, aws.s3.region: S3 credentials
     * - columns_from_path: Extract columns from file path
     * - list_files_only: Only list files without reading data
     * - list_recursively: Recursively list directories
     */
    private TPTNodeList<TFlinkTableProperty> properties;

    /**
     * Creates a new TFilesTableFunction.
     */
    public TFilesTableFunction() {
        this.functionType = EFunctionType.files_t;
    }

    /**
     * Initialize with properties list.
     * @param arg1 the properties list (TPTNodeList&lt;TFlinkTableProperty&gt;)
     */
    @Override
    public void init(Object arg1) {
        if (arg1 instanceof TPTNodeList) {
            @SuppressWarnings("unchecked")
            TPTNodeList<TFlinkTableProperty> props = (TPTNodeList<TFlinkTableProperty>) arg1;
            this.properties = props;
        }
    }

    /**
     * Initialize with function name and properties list.
     * @param arg1 the function name (TObjectName)
     * @param arg2 the properties list (TPTNodeList&lt;TFlinkTableProperty&gt;)
     */
    @Override
    public void init(Object arg1, Object arg2) {
        if (arg1 instanceof TObjectName) {
            this.functionName = (TObjectName) arg1;
        }
        if (arg2 instanceof TPTNodeList) {
            @SuppressWarnings("unchecked")
            TPTNodeList<TFlinkTableProperty> props = (TPTNodeList<TFlinkTableProperty>) arg2;
            this.properties = props;
        }
    }

    /**
     * Gets the properties list.
     * @return the list of key-value properties
     */
    public TPTNodeList<TFlinkTableProperty> getProperties() {
        return properties;
    }

    /**
     * Sets the properties list.
     * @param properties the list of key-value properties
     */
    public void setProperties(TPTNodeList<TFlinkTableProperty> properties) {
        this.properties = properties;
    }

    /**
     * Gets a property value by key name.
     * @param key the property key (without quotes)
     * @return the property value (without quotes), or null if not found
     */
    public String getPropertyValue(String key) {
        if (properties == null || key == null) return null;
        for (int i = 0; i < properties.size(); i++) {
            TFlinkTableProperty prop = properties.getElement(i);
            if (key.equals(prop.getKeyString())) {
                return prop.getValueString();
            }
        }
        return null;
    }

    /**
     * Gets the file path from the "path" property.
     * @return the file path, or null if not specified
     */
    public String getPath() {
        return getPropertyValue("path");
    }

    /**
     * Gets the file format from the "format" property.
     * @return the format (parquet, orc, csv, json, avro), or null if not specified
     */
    public String getFormat() {
        return getPropertyValue("format");
    }

    /**
     * Checks if this is a list-files-only operation.
     * @return true if list_files_only is "true", false otherwise
     */
    public boolean isListFilesOnly() {
        String value = getPropertyValue("list_files_only");
        return "true".equalsIgnoreCase(value);
    }

    /**
     * Checks if recursive listing is enabled.
     * @return true if list_recursively is "true", false otherwise
     */
    public boolean isListRecursively() {
        String value = getPropertyValue("list_recursively");
        return "true".equalsIgnoreCase(value);
    }

    /**
     * Gets the columns_from_path property value.
     * @return the columns_from_path value, or null if not specified
     */
    public String getColumnsFromPath() {
        return getPropertyValue("columns_from_path");
    }

    @Override
    public void doParse(TCustomSqlStatement psql, ESqlClause plocation) {
        this.dbvendor = psql.dbvendor;
        // FILES() properties don't need special parsing - they are literal string values
    }

    @Override
    public void accept(TParseTreeVisitor v) {
        v.preVisit(this);
        v.postVisit(this);
    }

    @Override
    public void acceptChildren(TParseTreeVisitor v) {
        v.preVisit(this);
        if (functionName != null) {
            functionName.acceptChildren(v);
        }
        if (properties != null) {
            properties.acceptChildren(v);
        }
        v.postVisit(this);
    }
}