/*
 * fy-atom.h - internal YAML atom methods
 *
 * Copyright (c) 2019 Pantelis Antoniou <pantelis.antoniou@konsulko.com>
 *
 * SPDX-License-Identifier: MIT
 */

#ifndef FY_ATOM_H
#define FY_ATOM_H

#ifdef HAVE_CONFIG_H
#include "config.h"
#endif

#include <stdint.h>
#include <stdbool.h>
#include <stdio.h>
#include <stdarg.h>

#include <libfyaml.h>

#include "fy-list.h"
#include "fy-ctype.h"

struct fy_reader;
struct fy_input;
struct fy_node;

enum fy_atom_style {
	/* YAML atoms */
	FYAS_PLAIN,
	FYAS_SINGLE_QUOTED,
	FYAS_DOUBLE_QUOTED,
	FYAS_LITERAL,
	FYAS_FOLDED,
	FYAS_URI,	/* special style for URIs */
	FYAS_COMMENT,	/* (possibly multi line) comment */
	FYAS_MANUAL_MARK = FY_BIT(3),
	FYAS_PLAIN_MANUAL = FYAS_PLAIN | FYAS_MANUAL_MARK,
	FYAS_SINGLE_QUOTED_MANUAL = FYAS_SINGLE_QUOTED | FYAS_MANUAL_MARK,
	FYAS_DOUBLE_QUOTED_MANUAL = FYAS_DOUBLE_QUOTED | FYAS_MANUAL_MARK,
	FYAS_LITERAL_MANUAL = FYAS_LITERAL | FYAS_MANUAL_MARK,
	FYAS_FOLDED_MANUAL = FYAS_FOLDED | FYAS_MANUAL_MARK,
};

static inline bool fy_atom_style_is_quoted(enum fy_atom_style style)
{
	style &= ~FYAS_MANUAL_MARK;
	return style == FYAS_SINGLE_QUOTED || style == FYAS_DOUBLE_QUOTED;
}

static inline bool fy_atom_style_is_block(enum fy_atom_style style)
{
	style &= ~FYAS_MANUAL_MARK;
	return style == FYAS_LITERAL || style == FYAS_FOLDED;
}

enum fy_atom_chomp {
	FYAC_STRIP,
	FYAC_CLIP,
	FYAC_KEEP,
};

/* analysis flags */
#define FYTTAF_BIT(x) ((uint64_t)1 << (x))

#define FYTTAF_HAS_LB			FYTTAF_BIT(0)
#define FYTTAF_HAS_WS			FYTTAF_BIT(1)
#define FYTTAF_HAS_CONSECUTIVE_LB	FYTTAF_BIT(2)
#define FYTTAF_HAS_START_LB		FYTTAF_BIT(3)	/* starts with linebreak */
#define FYTTAF_HAS_CONSECUTIVE_WS	FYTTAF_BIT(4)
#define FYTTAF_EMPTY			FYTTAF_BIT(5)
#define FYTTAF_CAN_BE_SIMPLE_KEY	FYTTAF_BIT(6)
#define FYTTAF_DIRECT_OUTPUT		FYTTAF_BIT(7)
#define FYTTAF_NO_TEXT_TOKEN		FYTTAF_BIT(8)
#define FYTTAF_TEXT_TOKEN		FYTTAF_BIT(9)
#define FYTTAF_CAN_BE_PLAIN		FYTTAF_BIT(10)
#define FYTTAF_CAN_BE_SINGLE_QUOTED	FYTTAF_BIT(11)
#define FYTTAF_CAN_BE_DOUBLE_QUOTED	FYTTAF_BIT(12)
#define FYTTAF_CAN_BE_LITERAL		FYTTAF_BIT(13)
#define FYTTAF_CAN_BE_FOLDED		FYTTAF_BIT(14)
#define FYTTAF_CAN_BE_PLAIN_FLOW	FYTTAF_BIT(15)
#define FYTTAF_QUOTE_AT_0		FYTTAF_BIT(16)
#define FYTTAF_CAN_BE_UNQUOTED_PATH_KEY	FYTTAF_BIT(17)
#define FYTTAF_HAS_ANY_LB		FYTTAF_BIT(18)	/* any LB including unicode, not per input */
#define FYTTAF_HAS_START_IND		FYTTAF_BIT(19)	/* has --- at col 0 */
#define FYTTAF_HAS_END_IND		FYTTAF_BIT(20)	/* has ... at col 0 */
#define FYTTAF_HAS_NON_PRINT		FYTTAF_BIT(21)	/* has any non printable utf8 */
#define FYTTAF_ENDS_WITH_COLON		FYTTAF_BIT(22)	/* ends with a colon */
#define FYTTAF_ALL_WS_LB		FYTTAF_BIT(23)	/* everything is ws or linebreak */
#define FYTTAF_ALL_PRINT_ASCII		FYTTAF_BIT(24)	/* everything is >= '!' && <= '~' */
#define FYTTAF_HAS_START_WS		FYTTAF_BIT(25)	/* leads with whitespace */
#define FYTTAF_SIZE0			FYTTAF_BIT(26)	/* zero sized */
#define FYTTAF_HAS_ZERO			FYTTAF_BIT(27)	/* contains a zero byte */
#define FYTTAF_HAS_NON_NL_LB		FYTTAF_BIT(28)	/* if it has a linebreak which is not \n */
#define FYTTAF_HAS_END_WS		FYTTAF_BIT(29)	/* ends with whitespace */
#define FYTTAF_HAS_END_LB		FYTTAF_BIT(30)	/* ends with linebreak */
#define FYTTAF_HAS_TRAILING_LB		FYTTAF_BIT(32)	/* ends with trailing lb > 1 */
#define FYTTAF_VALID_ANCHOR		FYTTAF_BIT(33)	/* valid anchor content (without & prefix) */
#define FYTTAF_JSON_ESCAPE		FYTTAF_BIT(34)	/* contains a character that JSON escapes */
#define FYTTAF_HIGH_ASCII		FYTTAF_BIT(35) 	/* contains a least one utf8 code >= 0x80 */

#define FYTTAF_ANALYZED			FYTTAF_BIT(63)	/* analyzed mark */

struct fy_text_analysis {
	uint64_t flags;
	int maxspan;
	int maxcol;
	int lbs;
	enum fy_scalar_style preferred_style;
};

struct fy_atom {
	struct fy_mark start_mark;
	struct fy_mark end_mark;
	size_t storage_hint;	/* guaranteed to fit in this amount of bytes */
	struct fy_input *fyi;	/* input on which atom is on */
	uint64_t fyi_generation;	/* to detect reallocs */
	unsigned int increment;
	union {
		uint64_t tozero;			/* fast way to zero everything here */
		struct {
			/* save a little bit of space with bitfields */
			unsigned int style : 8;	/* enum fy_atom_style, note that it's a big perf win for bytes */
			unsigned int chomp : 8; /* enum fy_atom_chomp */
			unsigned int tabsize : 8;
			int indent_delta : 8;		/* comment column offset from scope indent, clamped to [-128,127] */
			unsigned int lb_mode : 1; /* enum fy_lb_mode */
			unsigned int fws_mode : 1; /* enum fy_flow_ws_mode */
			unsigned int directive0_mode : 1;
			bool direct_output : 1;		/* can directly output */
			bool storage_hint_valid : 1;
			bool empty : 1;			/* atom contains whitespace and linebreaks only if length > 0 */
			bool has_lb : 1;		/* atom contains at least one linebreak */
			bool has_ws : 1;		/* atom contains at least one whitespace */
			bool starts_with_ws : 1;	/* atom starts with whitespace */
			bool starts_with_lb : 1;	/* atom starts with linebreak */
			bool ends_with_ws : 1;		/* atom ends with whitespace */
			bool ends_with_lb : 1;		/* atom ends with linebreak */
			bool trailing_lb : 1;		/* atom ends with trailing linebreaks > 1 */
			bool size0 : 1;			/* atom contains absolutely nothing */
			bool valid_anchor : 1;		/* atom is a valid anchor */
			bool json_mode : 1;		/* atom was read in json mode */
			bool ends_with_eof : 1;		/* atom ends at EOF of input */
			bool is_merge_key: 1;		/* atom is just << */
			bool simple_key_allowed : 1;	/* atom allows a simple key */
			bool high_ascii : 1;		/* atom has utf code point >= 0x80 (only for plains) */
			bool chomp_explicit : 1;	/* chomp was set during block scalar parsing */
			bool token_atom : 1;		/* we're an atom embedded in a token */
		};
	};
	struct fy_text_analysis analysis;
};

/* Set indent_delta, clamping to the [-128, 127] range of the 8-bit bitfield */
static inline void fy_atom_set_indent_delta(struct fy_atom *atom, int delta)
{
	atom->indent_delta = delta < -128 ? -128 : (delta > 127 ? 127 : delta);
}

static inline bool fy_atom_is_set(const struct fy_atom *atom)
{
	return atom && atom->fyi;
}

static inline void fy_atom_reset(struct fy_atom *atom)
{
	if (!atom)
		return;
	atom->fyi = NULL;
	atom->analysis.flags = 0;
}

static inline bool fy_atom_json_mode(struct fy_atom *handle)
{
	if (!handle)
		return false;

	return handle->json_mode;
}

static inline enum fy_lb_mode fy_atom_lb_mode(struct fy_atom *handle)
{
	if (!handle)
		return fylb_cr_nl;

	return handle->lb_mode;
}

static inline bool fy_atom_is_merge_key(struct fy_atom *handle)
{
	return handle && handle->is_merge_key;
}

static inline enum fy_flow_ws_mode fy_atom_flow_ws_mode(struct fy_atom *handle)
{
	if (!handle)
		return fyfws_space_tab;

	return handle->fws_mode;
}

/* all atoms are scalars so... */
static inline bool fy_atom_is_lb(struct fy_atom *handle, int c)
{
	return fy_is_generic_lb_m(c, fy_atom_lb_mode(handle));
}

static inline bool fy_atom_is_flow_ws(struct fy_atom *handle, int c)
{
	return fy_is_flow_ws_m(c, fy_atom_flow_ws_mode(handle));
}

ssize_t fy_atom_format_text_length(struct fy_atom *atom);
const char *fy_atom_format_text(struct fy_atom *atom, char *buf, size_t maxsz);

int fy_atom_format_utf8_length(struct fy_atom *atom);

static inline void
fy_atom_reset_storage_hints(struct fy_atom *handle)
{
	handle->storage_hint = 0;
	handle->storage_hint_valid = false;
}

struct fy_atom *fy_reader_fill_atom(struct fy_reader *fyr, int advance, struct fy_atom *handle);
struct fy_atom *fy_reader_fill_atom_mark(struct fy_reader *fyr, const struct fy_mark *start_mark,
					 const struct fy_mark *end_mark, struct fy_atom *handle);
struct fy_atom *fy_reader_fill_atom_at(struct fy_reader *fyr, int advance, int count, struct fy_atom *handle);

#define fy_reader_fill_atom_a(_fyr, _advance)  fy_reader_fill_atom((_fyr), (_advance), alloca(sizeof(struct fy_atom)))

struct fy_atom *fy_fill_node_atom(struct fy_node *fyn, struct fy_atom *handle);

#define fy_fill_node_atom_a(_fyn)  fy_fill_node_atom((_fyn), alloca(sizeof(struct fy_atom)))

struct fy_atom_iter_line_info {
	const char *start;
	const char *end;
	const char *nws_start;
	const char *nws_end;
	const char *chomp_start;
	bool empty : 1;
	bool trailing_breaks_ws : 1;
	bool first : 1;		/* first */
	bool last : 1;		/* last (only ws/lb afterwards */
	bool final : 1;		/* the final iterator */
	bool indented : 1;
	bool lb_end : 1;
	bool need_nl : 1;
	bool need_sep : 1;
	bool ends_with_backslash : 1;	/* last ended in \\ */
	size_t trailing_ws;
	size_t trailing_breaks;
	size_t start_ws, end_ws;
	const char *s;
	const char *e;
	int actual_lb;		/* the line break */
	const char *s_tb;	/* start of trailing breaks run */
	const char *e_tb;	/* end of trailing breaks run */
};

struct fy_atom_iter_chunk {
	struct fy_iter_chunk ic;
	/* note that it is guaranteed for copied chunks to be
	 * less or equal to 10 characters (the maximum digitbuf
	 * for double quoted escapes */
	char inplace_buf[10];	/* small copies in place */
};

#define NR_STARTUP_CHUNKS	8
#define SZ_STARTUP_COPY_BUFFER	32
#define SZ_UTF8_CACHE		128

struct fy_atom_iter {
	const struct fy_atom *atom;
	const char *s, *e;
	unsigned int chomp;
	int tabsize;
	bool single_line : 1;
	bool dangling_end_quote : 1;
	bool last_ends_with_backslash : 1;
	bool empty : 1;
	bool current : 1;
	bool done : 1;	/* last iteration (for block styles) */
	struct fy_atom_iter_line_info li[2];
	unsigned int alloc;
	unsigned int top;
	unsigned int read;
	struct fy_atom_iter_chunk *chunks;
	struct fy_atom_iter_chunk startup_chunks[NR_STARTUP_CHUNKS];
	int unget_c;
	/* small staging buffer to amortize chunk reads in fy_atom_iter_utf8_get() */
	size_t cache_pos;
	size_t cache_len;
	uint8_t cache_buf[SZ_UTF8_CACHE];
};

void fy_atom_iter_start(const struct fy_atom *atom, struct fy_atom_iter *iter);
void fy_atom_iter_finish(struct fy_atom_iter *iter);
const struct fy_iter_chunk *fy_atom_iter_peek_chunk(struct fy_atom_iter *iter);
const struct fy_iter_chunk *fy_atom_iter_chunk_next(struct fy_atom_iter *iter, const struct fy_iter_chunk *curr, int *errp);
void fy_atom_iter_advance(struct fy_atom_iter *iter, size_t len);

struct fy_atom_iter *fy_atom_iter_create(const struct fy_atom *atom);
void fy_atom_iter_destroy(struct fy_atom_iter *iter);
ssize_t fy_atom_iter_read(struct fy_atom_iter *iter, void *buf, size_t count);
int fy_atom_iter_getc(struct fy_atom_iter *iter);
int fy_atom_iter_ungetc(struct fy_atom_iter *iter, int c);
int fy_atom_iter_peekc(struct fy_atom_iter *iter);
int fy_atom_iter_utf8_get(struct fy_atom_iter *iter);
int fy_atom_iter_utf8_quoted_get(struct fy_atom_iter *iter, size_t *lenp, uint8_t *buf);
int fy_atom_iter_utf8_unget(struct fy_atom_iter *iter, int c);
int fy_atom_iter_utf8_peek(struct fy_atom_iter *iter);

int fy_atom_memcmp(struct fy_atom *atom, const void *ptr, size_t len);
int fy_atom_strcmp(struct fy_atom *atom, const char *str);
bool fy_atom_is_number(struct fy_atom *atom);
int fy_atom_cmp(struct fy_atom *atom1, struct fy_atom *atom2);

const char *fy_atom_data(const struct fy_atom *atom);

static inline size_t fy_atom_size(const struct fy_atom *atom)
{
	if (!atom)
		return 0;

	return atom->end_mark.input_pos - atom->start_mark.input_pos;
}

static inline bool fy_plain_atom_streq(const struct fy_atom *atom, const char *str)
{
	size_t size = strlen(str);

	if (!atom || !str || atom->style != FYAS_PLAIN || fy_atom_size(atom) != size)
		return false;

	return !memcmp(str, fy_atom_data(atom), size);
}

struct fy_raw_line {
	int lineno;
	const char *line_start;
	size_t line_len;
	size_t line_len_lb;
	size_t line_count;
	const char *content_start;
	size_t content_len;
	size_t content_start_count;
	size_t content_count;
	int content_start_col;
	int content_start_col8;	/* this is the tab 8 */
	int content_end_col;
	int content_end_col8;
};

struct fy_atom_raw_line_iter {
	const struct fy_atom *atom;
	const char *is, *ie;	/* input start, end */
	const char *as, *ae;	/* atom start, end */
	const char *rs;
	struct fy_raw_line line;
};

void fy_atom_raw_line_iter_start(const struct fy_atom *atom,
			     struct fy_atom_raw_line_iter *iter);
void fy_atom_raw_line_iter_finish(struct fy_atom_raw_line_iter *iter);

const struct fy_raw_line *
fy_atom_raw_line_iter_next(struct fy_atom_raw_line_iter *iter);

const char *
fy_atom_lines_containing(struct fy_atom *atom, size_t *lenp);

int
fy_atom_text_analyze_internal(
		struct fy_utf8_buf *ubuf,
		enum fy_atom_style style, enum fy_lb_mode lb_mode,
		struct fy_text_analysis *analysis);

int
fy_atom_text_analyze(struct fy_atom *handle, enum fy_atom_style style,
		     struct fy_text_analysis *analysis);

#endif