// Copyright 2022 Dietrich Epp.
// This file is part of SyncFiles. SyncFiles is licensed under the terms of the
// Mozilla Public License, version 2.0. See LICENSE.txt for details.
#ifndef CONVERT_CONVERT_H
#define CONVERT_CONVERT_H
// convert.h - character set conversion routines.

#include "lib/defs.h"
#include "lib/error.h"

enum {
	// Constants for CR and LF. Note that we should not use '\n' or '\r'
	// anywhere, because these character constants may have unexpected values on
	// certain old Mac OS compilers, depending on the compiler settings. In
	// particular, the values of '\n' and '\r' will be swapped.
	kCharLF = 10,
	kCharCR = 13,

	// Constant for substitution character: '?'.
	kCharSubstitute = 63
};

typedef enum {
	// Don't translite line breaks.
	kLineBreakKeep,

	// Convert line breaks to LF.
	kLineBreakLF,

	// Convert line breaks to CR.
	kLineBreakCR,

	// Convert line breaks to CR LF.
	kLineBreakCRLF
} LineBreakConversion;

// Directions that the converter runs in.
typedef enum {
	kToUTF8,
	kFromUTF8,
} ConvertDirection;

// Get the character map used for the given Mac OS script and region codes.
// Return -1 if no known character map exists.
int GetCharmap(int script, int region);

// The state of a converter. Must be zeroed prior to first conversion.
struct ConverterState {
	UInt32 data;
};

// Implementation function for building a converter.
typedef ErrorCode (*ConvertBuildf)(Handle *out, Handle data, Size datasz);

// Implementation function for running a converter.
typedef void (*ConvertRunf)(const void *cvtptr, LineBreakConversion lc,
                            struct ConverterState *stateptr, UInt8 **optr,
                            UInt8 *oend, const UInt8 **iptr, const UInt8 *iend);

// A converter. The converter can be freed by disposing the handle.
struct Converter {
	Handle data;
	ConvertRunf run;
};

// Build a converter from the given conversion table data.
int ConverterBuild(struct Converter *c, Handle data, Size datasz,
                   ConvertDirection direction);

// Engine 1: extended ASCII.

ErrorCode Convert1fBuild(Handle *out, Handle data, Size datasz);
void Convert1fRun(const void *cvtptr, LineBreakConversion lc,
                  struct ConverterState *stateptr, UInt8 **optr, UInt8 *oend,
                  const UInt8 **iptr, const UInt8 *iend);

ErrorCode Convert1rBuild(Handle *out, Handle data, Size datasz);
void Convert1rRun(const void *cvtptr, LineBreakConversion lc,
                  struct ConverterState *stateptr, UInt8 **optr, UInt8 *oend,
                  const UInt8 **iptr, const UInt8 *iend);

#endif