/*
  Copyright 2011-2017 David Robillard <http://drobilla.net>

  Permission to use, copy, modify, and/or distribute this software for any
  purpose with or without fee is hereby granted, provided that the above
  copyright notice and this permission notice appear in all copies.

  THIS SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
  WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
  MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
  ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
  WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
  ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
  OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*/

#ifndef SERD_READER_H
#define SERD_READER_H

#include "serd_internal.h"

#include "byte_source.h"
#include "node.h"
#include "stack.h"

#ifdef SERD_STACK_CHECK
#    define SERD_STACK_ASSERT_TOP(reader, ref) \
            assert(ref == reader->allocs[reader->n_allocs - 1]);
#else
#    define SERD_STACK_ASSERT_TOP(reader, ref)
#endif

/* Reference to a node in the stack (we can not use pointers since the
   stack may be reallocated, invalidating any pointers to elements).
*/
typedef size_t Ref;

typedef struct {
	Ref                 graph;
	Ref                 subject;
	Ref                 predicate;
	Ref                 object;
	Ref                 datatype;
	Ref                 lang;
	SerdStatementFlags* flags;
} ReadContext;

struct SerdReaderImpl {
	SerdWorld*               world;
	const SerdSinkInterface* sink;
	SerdErrorSink            error_sink;
	void*                    error_handle;
	Ref                      rdf_first;
	Ref                      rdf_rest;
	Ref                      rdf_nil;
	SerdNode*                default_graph;
	SerdByteSource           source;
	SerdStack                stack;
	SerdSyntax               syntax;
	unsigned                 next_id;
	SerdStatus               status;
	uint8_t*                 buf;
	char*                    bprefix;
	size_t                   bprefix_len;
	bool                     strict; ///< True iff strict parsing
	bool                     seen_genid;
#ifdef SERD_STACK_CHECK
	Ref*                     allocs; ///< Stack of push offsets
	size_t                   n_allocs; ///< Number of stack pushes
#endif
};

int r_err(SerdReader* reader, SerdStatus st, const char* fmt, ...);

Ref push_node_padded(SerdReader* reader,
                     size_t      maxlen,
                     SerdType    type,
                     const char* str,
                     size_t      n_bytes);

Ref push_node(SerdReader* reader,
              SerdType    type,
              const char* str,
              size_t      n_bytes);

size_t genid_size(SerdReader* reader);
Ref    blank_id(SerdReader* reader);
void   set_blank_id(SerdReader* reader, Ref ref, size_t buf_size);

SerdNode* deref(SerdReader* reader, Ref ref);

Ref pop_node(SerdReader* reader, Ref ref);

bool emit_statement(SerdReader* reader, ReadContext ctx, Ref o, Ref d, Ref l);

bool read_n3_statement(SerdReader* reader);
SerdStatus read_nquadsDoc(SerdReader* reader);
SerdStatus read_turtleTrigDoc(SerdReader* reader);

static inline uint8_t
peek_byte(SerdReader* reader)
{
	return serd_byte_source_peek(&reader->source);
}

static inline uint8_t
eat_byte(SerdReader* reader)
{
	const uint8_t    c  = peek_byte(reader);
	const SerdStatus st = serd_byte_source_advance(&reader->source);
	if (st) {
		reader->status = st;
	}
	return c;
}

static inline uint8_t
eat_byte_safe(SerdReader* reader, const uint8_t byte)
{
	const uint8_t c = eat_byte(reader);
	assert(c == byte);
	return c;
}

static inline uint8_t
eat_byte_check(SerdReader* reader, const uint8_t byte)
{
	const uint8_t c = peek_byte(reader);
	if (c != byte) {
		return r_err(reader, SERD_ERR_BAD_SYNTAX,
		             "expected `%c', not `%c'\n", byte, c);
	}
	return eat_byte_safe(reader, byte);
}

static inline bool
eat_string(SerdReader* reader, const char* str, unsigned n)
{
	bool bad = false;
	for (unsigned i = 0; i < n; ++i) {
		bad |= (bool)eat_byte_check(reader, ((const uint8_t*)str)[i]);
	}
	return bad;
}

static inline SerdStatus
push_byte(SerdReader* reader, Ref ref, const uint8_t c)
{
	SERD_STACK_ASSERT_TOP(reader, ref);
	char* const     s    = (char*)serd_stack_push(&reader->stack, 1);
	SerdNode* const node = (SerdNode*)(reader->stack.buf + ref);
	++node->n_bytes;
	*(s - 1) = c;
	*s       = '\0';
	return SERD_SUCCESS;
}

static inline void
push_bytes(SerdReader* reader, Ref ref, const uint8_t* bytes, unsigned len)
{
	for (unsigned i = 0; i < len; ++i) {
		push_byte(reader, ref, bytes[i]);
	}
}

#endif // SERD_READER_H