/**
 * @file prism.h
 *
 * The main header file for the prism parser.
 */
#ifndef PRISM_H
#define PRISM_H

#include "prism/defines.h"
#include "prism/util/pm_buffer.h"
#include "prism/util/pm_char.h"
#include "prism/util/pm_integer.h"
#include "prism/util/pm_memchr.h"
#include "prism/util/pm_strncasecmp.h"
#include "prism/util/pm_strpbrk.h"
#include "prism/ast.h"
#include "prism/diagnostic.h"
#include "prism/node.h"
#include "prism/options.h"
#include "prism/pack.h"
#include "prism/parser.h"
#include "prism/prettyprint.h"
#include "prism/regexp.h"
#include "prism/static_literals.h"
#include "prism/version.h"

#include <assert.h>
#include <errno.h>
#include <locale.h>
#include <math.h>
#include <stdarg.h>
#include <stdbool.h>
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#ifndef _WIN32
#include <strings.h>
#endif

/**
 * The prism version and the serialization format.
 *
 * @returns The prism version as a constant string.
 */
PRISM_EXPORTED_FUNCTION const char * pm_version(void);

/**
 * Initialize a parser with the given start and end pointers.
 *
 * The resulting parser must eventually be freed with `pm_parser_free()`.
 *
 * @param parser The parser to initialize.
 * @param source The source to parse.
 * @param size The size of the source.
 * @param options The optional options to use when parsing. These options must
 *   live for the whole lifetime of this parser.
 *
 * \public \memberof pm_parser
 */
PRISM_EXPORTED_FUNCTION void pm_parser_init(pm_parser_t *parser, const uint8_t *source, size_t size, const pm_options_t *options);

/**
 * Register a callback that will be called whenever prism changes the encoding
 * it is using to parse based on the magic comment.
 *
 * @param parser The parser to register the callback with.
 * @param callback The callback to register.
 *
 * \public \memberof pm_parser
 */
PRISM_EXPORTED_FUNCTION void pm_parser_register_encoding_changed_callback(pm_parser_t *parser, pm_encoding_changed_callback_t callback);

/**
 * Free any memory associated with the given parser.
 *
 * This does not free the `pm_options_t` object that was used to initialize the
 * parser.
 *
 * @param parser The parser to free.
 *
 * \public \memberof pm_parser
 */
PRISM_EXPORTED_FUNCTION void pm_parser_free(pm_parser_t *parser);

/**
 * Initiate the parser with the given parser.
 *
 * @param parser The parser to use.
 * @return The AST representing the source.
 *
 * \public \memberof pm_parser
 */
PRISM_EXPORTED_FUNCTION pm_node_t * pm_parse(pm_parser_t *parser);

/**
 * This function is used in pm_parse_stream() to retrieve a line of input from a
 * stream. It closely mirrors that of fgets so that fgets can be used as the
 * default implementation.
 */
typedef char * (pm_parse_stream_fgets_t)(char *string, int size, void *stream);

/**
 * This function is used in pm_parse_stream to check whether a stream is EOF.
 * It closely mirrors that of feof so that feof can be used as the
 * default implementation.
 */
typedef int (pm_parse_stream_feof_t)(void *stream);

/**
 * Parse a stream of Ruby source and return the tree.
 *
 * @param parser The parser to use.
 * @param buffer The buffer to use.
 * @param stream The stream to parse.
 * @param stream_fgets The function to use to read from the stream.
 * @param stream_feof The function to use to determine if the stream has hit eof.
 * @param options The optional options to use when parsing.
 * @return The AST representing the source.
 *
 * \public \memberof pm_parser
 */
PRISM_EXPORTED_FUNCTION pm_node_t * pm_parse_stream(pm_parser_t *parser, pm_buffer_t *buffer, void *stream, pm_parse_stream_fgets_t *stream_fgets, pm_parse_stream_feof_t *stream_feof, const pm_options_t *options);

// We optionally support serializing to a binary string. For systems that don't
// want or need this functionality, it can be turned off with the
// PRISM_EXCLUDE_SERIALIZATION define.
#ifndef PRISM_EXCLUDE_SERIALIZATION

/**
 * Parse and serialize the AST represented by the source that is read out of the
 * given stream into to the given buffer.
 *
 * @param buffer The buffer to serialize to.
 * @param stream The stream to parse.
 * @param stream_fgets The function to use to read from the stream.
 * @param stream_feof The function to use to tell if the stream has hit eof.
 * @param data The optional data to pass to the parser.
 */
PRISM_EXPORTED_FUNCTION void pm_serialize_parse_stream(pm_buffer_t *buffer, void *stream, pm_parse_stream_fgets_t *stream_fgets, pm_parse_stream_feof_t *stream_feof, const char *data);

/**
 * Serialize the given list of comments to the given buffer.
 *
 * @param parser The parser to serialize.
 * @param list The list of comments to serialize.
 * @param buffer The buffer to serialize to.
 */
void pm_serialize_comment_list(pm_parser_t *parser, pm_list_t *list, pm_buffer_t *buffer);

/**
 * Serialize the name of the encoding to the buffer.
 *
 * @param encoding The encoding to serialize.
 * @param buffer The buffer to serialize to.
 */
void pm_serialize_encoding(const pm_encoding_t *encoding, pm_buffer_t *buffer);

/**
 * Serialize the encoding, metadata, nodes, and constant pool.
 *
 * @param parser The parser to serialize.
 * @param node The node to serialize.
 * @param buffer The buffer to serialize to.
 */
void pm_serialize_content(pm_parser_t *parser, pm_node_t *node, pm_buffer_t *buffer);

/**
 * Serialize the AST represented by the given node to the given buffer.
 *
 * @param parser The parser to serialize.
 * @param node The node to serialize.
 * @param buffer The buffer to serialize to.
 */
PRISM_EXPORTED_FUNCTION void pm_serialize(pm_parser_t *parser, pm_node_t *node, pm_buffer_t *buffer);

/**
 * Parse the given source to the AST and dump the AST to the given buffer.
 *
 * @param buffer The buffer to serialize to.
 * @param source The source to parse.
 * @param size The size of the source.
 * @param data The optional data to pass to the parser.
 */
PRISM_EXPORTED_FUNCTION void pm_serialize_parse(pm_buffer_t *buffer, const uint8_t *source, size_t size, const char *data);

/**
 * Parse and serialize the comments in the given source to the given buffer.
 *
 * @param buffer The buffer to serialize to.
 * @param source The source to parse.
 * @param size The size of the source.
 * @param data The optional data to pass to the parser.
 */
PRISM_EXPORTED_FUNCTION void pm_serialize_parse_comments(pm_buffer_t *buffer, const uint8_t *source, size_t size, const char *data);

/**
 * Lex the given source and serialize to the given buffer.
 *
 * @param source The source to lex.
 * @param size The size of the source.
 * @param buffer The buffer to serialize to.
 * @param data The optional data to pass to the lexer.
 */
PRISM_EXPORTED_FUNCTION void pm_serialize_lex(pm_buffer_t *buffer, const uint8_t *source, size_t size, const char *data);

/**
 * Parse and serialize both the AST and the tokens represented by the given
 * source to the given buffer.
 *
 * @param buffer The buffer to serialize to.
 * @param source The source to parse.
 * @param size The size of the source.
 * @param data The optional data to pass to the parser.
 */
PRISM_EXPORTED_FUNCTION void pm_serialize_parse_lex(pm_buffer_t *buffer, const uint8_t *source, size_t size, const char *data);

#endif

/**
 * Parse the source and return true if it parses without errors or warnings.
 *
 * @param source The source to parse.
 * @param size The size of the source.
 * @param data The optional data to pass to the parser.
 * @return True if the source parses without errors or warnings.
 */
PRISM_EXPORTED_FUNCTION bool pm_parse_success_p(const uint8_t *source, size_t size, const char *data);

/**
 * Returns a string representation of the given token type.
 *
 * @param token_type The token type to convert to a string.
 * @return A string representation of the given token type.
 */
PRISM_EXPORTED_FUNCTION const char * pm_token_type_name(pm_token_type_t token_type);

/**
 * Returns the human name of the given token type.
 *
 * @param token_type The token type to convert to a human name.
 * @return The human name of the given token type.
 */
const char * pm_token_type_human(pm_token_type_t token_type);

// We optionally support dumping to JSON. For systems that don't want or need
// this functionality, it can be turned off with the PRISM_EXCLUDE_JSON define.
#ifndef PRISM_EXCLUDE_JSON

/**
 * Dump JSON to the given buffer.
 *
 * @param buffer The buffer to serialize to.
 * @param parser The parser that parsed the node.
 * @param node The node to serialize.
 */
PRISM_EXPORTED_FUNCTION void pm_dump_json(pm_buffer_t *buffer, const pm_parser_t *parser, const pm_node_t *node);

#endif

/**
 * Represents the results of a slice query.
 */
typedef enum {
    /** Returned if the encoding given to a slice query was invalid. */
    PM_STRING_QUERY_ERROR = -1,

    /** Returned if the result of the slice query is false. */
    PM_STRING_QUERY_FALSE,

    /** Returned if the result of the slice query is true. */
    PM_STRING_QUERY_TRUE
} pm_string_query_t;

/**
 * Check that the slice is a valid local variable name.
 *
 * @param source The source to check.
 * @param length The length of the source.
 * @param encoding_name The name of the encoding of the source.
 * @return PM_STRING_QUERY_TRUE if the query is true, PM_STRING_QUERY_FALSE if
 *   the query is false, and PM_STRING_QUERY_ERROR if the encoding was invalid.
 */
PRISM_EXPORTED_FUNCTION pm_string_query_t pm_string_query_local(const uint8_t *source, size_t length, const char *encoding_name);

/**
 * Check that the slice is a valid constant name.
 *
 * @param source The source to check.
 * @param length The length of the source.
 * @param encoding_name The name of the encoding of the source.
 * @return PM_STRING_QUERY_TRUE if the query is true, PM_STRING_QUERY_FALSE if
 *   the query is false, and PM_STRING_QUERY_ERROR if the encoding was invalid.
 */
PRISM_EXPORTED_FUNCTION pm_string_query_t pm_string_query_constant(const uint8_t *source, size_t length, const char *encoding_name);

/**
 * Check that the slice is a valid method name.
 *
 * @param source The source to check.
 * @param length The length of the source.
 * @param encoding_name The name of the encoding of the source.
 * @return PM_STRING_QUERY_TRUE if the query is true, PM_STRING_QUERY_FALSE if
 *   the query is false, and PM_STRING_QUERY_ERROR if the encoding was invalid.
 */
PRISM_EXPORTED_FUNCTION pm_string_query_t pm_string_query_method_name(const uint8_t *source, size_t length, const char *encoding_name);

/**
 * @mainpage
 *
 * Prism is a parser for the Ruby programming language. It is designed to be
 * portable, error tolerant, and maintainable. It is written in C99 and has no
 * dependencies. It is currently being integrated into
 * [CRuby](https://github.com/ruby/ruby),
 * [JRuby](https://github.com/jruby/jruby),
 * [TruffleRuby](https://github.com/oracle/truffleruby),
 * [Sorbet](https://github.com/sorbet/sorbet), and
 * [Syntax Tree](https://github.com/ruby-syntax-tree/syntax_tree).
 *
 * @section getting-started Getting started
 *
 * If you're vendoring this project and compiling it statically then as long as
 * you have a C99 compiler you will be fine. If you're linking against it as
 * shared library, then you should compile with `-fvisibility=hidden` and
 * `-DPRISM_EXPORT_SYMBOLS` to tell prism to make only its public interface
 * visible.
 *
 * @section parsing Parsing
 *
 * In order to parse Ruby code, the structures and functions that you're going
 * to want to use and be aware of are:
 *
 * * `pm_parser_t` - the main parser structure
 * * `pm_parser_init()` - initialize a parser
 * * `pm_parse()` - parse and return the root node
 * * `pm_node_destroy()` - deallocate the root node returned by `pm_parse()`
 * * `pm_parser_free()` - free the internal memory of the parser
 *
 * Putting all of this together would look something like:
 *
 * ```c
 * void parse(const uint8_t *source, size_t length) {
 *     pm_parser_t parser;
 *     pm_parser_init(&parser, source, length, NULL);
 *
 *     pm_node_t *root = pm_parse(&parser);
 *     printf("PARSED!\n");
 *
 *     pm_node_destroy(&parser, root);
 *     pm_parser_free(&parser);
 * }
 * ```
 *
 * All of the nodes "inherit" from `pm_node_t` by embedding those structures
 * as their first member. This means you can downcast and upcast any node in the
 * tree to a `pm_node_t`.
 *
 * @section serializing Serializing
 *
 * Prism provides the ability to serialize the AST and its related metadata into
 * a binary format. This format is designed to be portable to different
 * languages and runtimes so that you only need to make one FFI call in order to
 * parse Ruby code. The structures and functions that you're going to want to
 * use and be aware of are:
 *
 * * `pm_buffer_t` - a small buffer object that will hold the serialized AST
 * * `pm_buffer_free()` - free the memory associated with the buffer
 * * `pm_serialize()` - serialize the AST into a buffer
 * * `pm_serialize_parse()` - parse and serialize the AST into a buffer
 *
 * Putting all of this together would look something like:
 *
 * ```c
 * void serialize(const uint8_t *source, size_t length) {
 *     pm_buffer_t buffer = { 0 };
 *
 *     pm_serialize_parse(&buffer, source, length, NULL);
 *     printf("SERIALIZED!\n");
 *
 *     pm_buffer_free(&buffer);
 * }
 * ```
 *
 * @section inspecting Inspecting
 *
 * Prism provides the ability to inspect the AST by pretty-printing nodes. You
 * can do this with the `pm_prettyprint()` function, which you would use like:
 *
 * ```c
 * void prettyprint(const uint8_t *source, size_t length) {
 *     pm_parser_t parser;
 *     pm_parser_init(&parser, source, length, NULL);
 *
 *     pm_node_t *root = pm_parse(&parser);
 *     pm_buffer_t buffer = { 0 };
 *
 *     pm_prettyprint(&buffer, &parser, root);
 *     printf("%*.s\n", (int) buffer.length, buffer.value);
 *
 *     pm_buffer_free(&buffer);
 *     pm_node_destroy(&parser, root);
 *     pm_parser_free(&parser);
 * }
 * ```
 */

#endif
