/* ScummVM - Graphic Adventure Engine
 *
 * ScummVM is the legal property of its developers, whose names
 * are too numerous to list here. Please refer to the COPYRIGHT
 * file distributed with this source distribution.
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version 2
 * of the License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
 *
 */


#include "glk/jacl/csv.h"

namespace Glk {
namespace JACL {

#define VERSION "3.0.0"

//#define SIZE_MAX ((size_t)-1)

#define ROW_NOT_BEGUN           0
#define FIELD_NOT_BEGUN         1
#define FIELD_BEGUN             2
#define FIELD_MIGHT_HAVE_ENDED  3

/*
  Explanation of states
  ROW_NOT_BEGUN    There have not been any fields encountered for this row
  FIELD_NOT_BEGUN  There have been fields but we are currently not in one
  FIELD_BEGUN      We are in a field
  FIELD_MIGHT_HAVE_ENDED
                   We encountered a double quote inside a quoted field, the
                   field is either ended or the quote is literal
*/

#define MEM_BLK_SIZE 128

#define SUBMIT_FIELD(p) \
	do { \
		if (!quoted) \
			entry_pos -= spaces; \
		if (p->options & CSV_APPEND_NULL) \
			((p)->entry_buf[entry_pos+1]) = '\0'; \
		if (cb1) \
			cb1(p->entry_buf, entry_pos, data); \
		pstate = FIELD_NOT_BEGUN; \
		entry_pos = quoted = spaces = 0; \
	} while (0)

#define SUBMIT_ROW(p, c) \
	do { \
		if (cb2) \
			cb2(c, data); \
		pstate = ROW_NOT_BEGUN; \
		entry_pos = quoted = spaces = 0; \
	} while (0)

#define SUBMIT_CHAR(p, c) ((p)->entry_buf[entry_pos++] = (c))

static char *csv_errors[] = {"success",
                             "error parsing data while strict checking enabled",
                             "memory exhausted while increasing buffer size",
                             "data size too large",
                             "invalid status code"
                            };

int csv_error(struct csv_parser *p) {
	/* Return the current status of the parser */
	return p->status;
}

char *csv_strerror(int status) {
	/* Return a textual description of status */
	if (status >= CSV_EINVALID || status < 0)
		return csv_errors[CSV_EINVALID];
	else
		return csv_errors[status];
}

int csv_get_opts(struct csv_parser *p) {
	/* Return the currently set options of parser */
	if (p == NULL)
		return -1;

	return p->options;
}

int csv_set_opts(struct csv_parser *p, unsigned char options) {
	/* Set the options */
	if (p == NULL)
		return -1;

	p->options = options;
	return 0;
}

int csv_init(struct csv_parser *p, unsigned char options) {
	/* Initialize a csv_parser object returns 0 on success, -1 on error */
	if (p == NULL)
		return -1;

	p->entry_buf = NULL;
	p->pstate = ROW_NOT_BEGUN;
	p->quoted = 0;
	p->spaces = 0;
	p->entry_pos = 0;
	p->entry_size = 0;
	p->status = 0;
	p->options = options;
	p->quote_char = CSV_QUOTE;
	p->delim_char = CSV_COMMA;
	p->is_space = NULL;
	p->is_term = NULL;
	p->blk_size = MEM_BLK_SIZE;
	p->malloc_func = NULL;
	p->realloc_func = realloc;
	p->free_func = free;

	return 0;
}

void csv_free(struct csv_parser *p) {
	/* Free the entry_buffer of csv_parser object */
	if (p == NULL)
		return;

	if (p->entry_buf)
		p->free_func(p->entry_buf);

	p->entry_buf = NULL;
	p->entry_size = 0;

	return;
}

int csv_fini(struct csv_parser *p, void (*cb1)(void *, size_t, void *), void (*cb2)(int c, void *), void *data) {
	/* Finalize parsing.  Needed, for example, when file does not end in a newline */
	int quoted = p->quoted;
	int pstate = p->pstate;
	size_t spaces = p->spaces;
	size_t entry_pos = p->entry_pos;

	if (p == NULL)
		return -1;


	if (p->pstate == FIELD_BEGUN && p->quoted && p->options & CSV_STRICT && p->options & CSV_STRICT_FINI) {
		/* Current field is quoted, no end-quote was seen, and CSV_STRICT_FINI is set */
		p->status = CSV_EPARSE;
		return -1;
	}

	switch (p->pstate) {
	case FIELD_MIGHT_HAVE_ENDED:
		p->entry_pos -= p->spaces + 1;  /* get rid of spaces and original quote */
	/* Fall-through */
	case FIELD_NOT_BEGUN:
	case FIELD_BEGUN:
		quoted = p->quoted, pstate = p->pstate;
		spaces = p->spaces, entry_pos = p->entry_pos;
		SUBMIT_FIELD(p);
		SUBMIT_ROW(p, -1);
	case ROW_NOT_BEGUN: /* Already ended properly */
		;
	}

	/* Reset parser */
	p->spaces = p->quoted = p->entry_pos = p->status = 0;
	p->pstate = ROW_NOT_BEGUN;

	return 0;
}

void csv_set_delim(struct csv_parser *p, unsigned char c) {
	/* Set the delimiter */
	if (p) p->delim_char = c;
}

void csv_set_quote(struct csv_parser *p, unsigned char c) {
	/* Set the quote character */
	if (p) p->quote_char = c;
}

unsigned char csv_get_delim(struct csv_parser *p) {
	/* Get the delimiter */
	return p->delim_char;
}

unsigned char csv_get_quote(struct csv_parser *p) {
	/* Get the quote character */
	return p->quote_char;
}

void csv_set_space_func(struct csv_parser *p, int (*f)(unsigned char)) {
	/* Set the space function */
	if (p) p->is_space = f;
}

void csv_set_term_func(struct csv_parser *p, int (*f)(unsigned char)) {
	/* Set the term function */
	if (p) p->is_term = f;
}

void csv_set_realloc_func(struct csv_parser *p, void *(*f)(void *, size_t)) {
	/* Set the realloc function used to increase buffer size */
	if (p && f) p->realloc_func = f;
}

void csv_set_free_func(struct csv_parser *p, void (*f)(void *)) {
	/* Set the free function used to free the buffer */
	if (p && f) p->free_func = f;
}

void csv_set_blk_size(struct csv_parser *p, size_t size) {
	/* Set the block size used to increment buffer size */
	if (p) p->blk_size = size;
}

size_t csv_get_buffer_size(struct csv_parser *p) {
	/* Get the size of the entry buffer */
	if (p)
		return p->entry_size;
	return 0;
}

static int csv_increase_buffer(struct csv_parser *p) {
	/* Increase the size of the entry buffer.  Attempt to increase size by
	 * p->blk_size, if this is larger than SIZE_MAX try to increase current
	 * buffer size to SIZE_MAX.  If allocation fails, try to allocate halve
	 * the size and try again until successful or increment size is zero.
	 */

	size_t to_add = p->blk_size;
	void *vp;

	if (p->entry_size >= SIZE_MAX - to_add)
		to_add = SIZE_MAX - p->entry_size;

	if (!to_add) {
		p->status = CSV_ETOOBIG;
		return -1;
	}

	while ((vp = p->realloc_func(p->entry_buf, p->entry_size + to_add)) == NULL) {
		to_add /= 2;
		if (!to_add) {
			p->status = CSV_ENOMEM;
			return -1;
		}
	}

	/* Update entry buffer pointer and entry_size if successful */
	p->entry_buf = (unsigned char *)vp;
	p->entry_size += to_add;
	return 0;
}

size_t csv_parse(struct csv_parser *p, const void *s, size_t len, void (*cb1)(void *, size_t, void *),
                 void (*cb2)(int c, void *), void *data) {
	unsigned const char *us = (unsigned const char *)s;  /* Access input data as array of unsigned char */
	unsigned char c;              /* The character we are currently processing */
	size_t pos = 0;               /* The number of characters we have processed in this call */

	/* Store key fields into local variables for performance */
	unsigned char delim = p->delim_char;
	unsigned char quote = p->quote_char;
	int (*is_space)(unsigned char) = p->is_space;
	int (*is_term)(unsigned char) = p->is_term;
	int quoted = p->quoted;
	int pstate = p->pstate;
	size_t spaces = p->spaces;
	size_t entry_pos = p->entry_pos;


	if (!p->entry_buf && pos < len) {
		/* Buffer hasn't been allocated yet and len > 0 */
		if (csv_increase_buffer(p) != 0) {
			p->quoted = quoted, p->pstate = pstate, p->spaces = spaces, p->entry_pos = entry_pos;
			return pos;
		}
	}

	while (pos < len) {
		/* Check memory usage, increase buffer if neccessary */
		if (entry_pos == ((p->options & CSV_APPEND_NULL) ? p->entry_size - 1 : p->entry_size)) {
			if (csv_increase_buffer(p) != 0) {
				p->quoted = quoted, p->pstate = pstate, p->spaces = spaces, p->entry_pos = entry_pos;
				return pos;
			}
		}

		c = us[pos++];

		switch (pstate) {
		case ROW_NOT_BEGUN:
		case FIELD_NOT_BEGUN:
			if (is_space ? is_space(c) : c == CSV_SPACE || c == CSV_TAB) { /* Space or Tab */
				continue;
			} else if (is_term ? is_term(c) : c == CSV_CR || c == CSV_LF) { /* Carriage Return or Line Feed */
				if (pstate == FIELD_NOT_BEGUN) {
					SUBMIT_FIELD(p);
					SUBMIT_ROW(p, (unsigned char)c);
				} else {  /* ROW_NOT_BEGUN */
					/* Don't submit empty rows by default */
					if (p->options & CSV_REPALL_NL) {
						SUBMIT_ROW(p, (unsigned char)c);
					}
				}
				continue;
			} else if (c == delim) { /* Comma */
				SUBMIT_FIELD(p);
				break;
			} else if (c == quote) { /* Quote */
				pstate = FIELD_BEGUN;
				quoted = 1;
			} else {               /* Anything else */
				pstate = FIELD_BEGUN;
				quoted = 0;
				SUBMIT_CHAR(p, c);
			}
			break;
		case FIELD_BEGUN:
			if (c == quote) {         /* Quote */
				if (quoted) {
					SUBMIT_CHAR(p, c);
					pstate = FIELD_MIGHT_HAVE_ENDED;
				} else {
					/* STRICT ERROR - double quote inside non-quoted field */
					if (p->options & CSV_STRICT) {
						p->status = CSV_EPARSE;
						p->quoted = quoted, p->pstate = pstate, p->spaces = spaces, p->entry_pos = entry_pos;
						return pos - 1;
					}
					SUBMIT_CHAR(p, c);
					spaces = 0;
				}
			} else if (c == delim) {  /* Comma */
				if (quoted) {
					SUBMIT_CHAR(p, c);
				} else {
					SUBMIT_FIELD(p);
				}
			} else if (is_term ? is_term(c) : c == CSV_CR || c == CSV_LF) {  /* Carriage Return or Line Feed */
				if (!quoted) {
					SUBMIT_FIELD(p);
					SUBMIT_ROW(p, (unsigned char)c);
				} else {
					SUBMIT_CHAR(p, c);
				}
			} else if (!quoted && (is_space ? is_space(c) : c == CSV_SPACE || c == CSV_TAB)) { /* Tab or space for non-quoted field */
				SUBMIT_CHAR(p, c);
				spaces++;
			} else {  /* Anything else */
				SUBMIT_CHAR(p, c);
				spaces = 0;
			}
			break;
		case FIELD_MIGHT_HAVE_ENDED:
			/* This only happens when a quote character is encountered in a quoted field */
			if (c == delim) {  /* Comma */
				entry_pos -= spaces + 1;  /* get rid of spaces and original quote */
				SUBMIT_FIELD(p);
			} else if (is_term ? is_term(c) : c == CSV_CR || c == CSV_LF) {  /* Carriage Return or Line Feed */
				entry_pos -= spaces + 1;  /* get rid of spaces and original quote */
				SUBMIT_FIELD(p);
				SUBMIT_ROW(p, (unsigned char)c);
			} else if (is_space ? is_space(c) : c == CSV_SPACE || c == CSV_TAB) {  /* Space or Tab */
				SUBMIT_CHAR(p, c);
				spaces++;
			} else if (c == quote) {  /* Quote */
				if (spaces) {
					/* STRICT ERROR - unescaped double quote */
					if (p->options & CSV_STRICT) {
						p->status = CSV_EPARSE;
						p->quoted = quoted, p->pstate = pstate, p->spaces = spaces, p->entry_pos = entry_pos;
						return pos - 1;
					}
					spaces = 0;
					SUBMIT_CHAR(p, c);
				} else {
					/* Two quotes in a row */
					pstate = FIELD_BEGUN;
				}
			} else {  /* Anything else */
				/* STRICT ERROR - unescaped double quote */
				if (p->options & CSV_STRICT) {
					p->status = CSV_EPARSE;
					p->quoted = quoted, p->pstate = pstate, p->spaces = spaces, p->entry_pos = entry_pos;
					return pos - 1;
				}
				pstate = FIELD_BEGUN;
				spaces = 0;
				SUBMIT_CHAR(p, c);
			}
			break;
		default:
			break;
		}
	}
	p->quoted = quoted, p->pstate = pstate, p->spaces = spaces, p->entry_pos = entry_pos;
	return pos;
}

size_t csv_write(void *dest, size_t dest_size, const void *src, size_t src_size) {
	unsigned char *cdest = (unsigned char *)dest;
	const unsigned char *csrc = (const unsigned char *)src;
	size_t chars = 0;

	if (src == NULL)
		return 0;

	if (cdest == NULL)
		dest_size = 0;

	if (dest_size > 0)
		*cdest++ = '"';
	chars++;

	while (src_size) {
		if (*csrc == '"') {
			if (dest_size > chars)
				*cdest++ = '"';
			if (chars < SIZE_MAX) chars++;
		}
		if (dest_size > chars)
			*cdest++ = *csrc;
		if (chars < SIZE_MAX) chars++;
		src_size--;
		csrc++;
	}

	if (dest_size > chars)
		*cdest = '"';
	if (chars < SIZE_MAX) chars++;

	return chars;
}

int csv_fwrite(Common::WriteStream *fp, const void *src, size_t src_size) {
	const unsigned char *csrc = (const unsigned char *)src;

	if (fp == NULL || src == NULL)
		return 0;

	fp->writeByte('"');

	while (src_size) {
		if (*csrc == '"') {
			fp->writeByte('"');
		}
		fp->writeByte(*csrc);
		src_size--;
		csrc++;
	}

	fp->writeByte('"');
	return 0;
}

size_t csv_write2(void *dest, size_t dest_size, const void *src, size_t src_size, unsigned char quote) {
	unsigned char *cdest = (unsigned char *)dest;
	const unsigned char *csrc = (const unsigned char *)src;
	size_t chars = 0;

	if (src == NULL)
		return 0;

	if (dest == NULL)
		dest_size = 0;

	if (dest_size > 0)
		*cdest++ = quote;
	chars++;

	while (src_size) {
		if (*csrc == quote) {
			if (dest_size > chars)
				*cdest++ = quote;
			if (chars < SIZE_MAX) chars++;
		}
		if (dest_size > chars)
			*cdest++ = *csrc;
		if (chars < SIZE_MAX) chars++;
		src_size--;
		csrc++;
	}

	if (dest_size > chars)
		*cdest = quote;
	if (chars < SIZE_MAX) chars++;

	return chars;
}

int csv_fwrite2(Common::WriteStream *fp, const void *src, size_t src_size, unsigned char quote) {
	const unsigned char *csrc = (const unsigned char *)src;

	if (fp == NULL || src == NULL)
		return 0;

	fp->writeByte(quote);

	while (src_size) {
		if (*csrc == quote) {
			fp->writeByte(quote);
		}
		fp->writeByte(*csrc);
		src_size--;
		csrc++;
	}

	fp->writeByte(quote);
	return 0;
}

} // End of namespace JACL
} // End of namespace Glk