/*
  Copyright 2011 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.
*/

#include <assert.h>
#include <stdbool.h>
#include <stdlib.h>
#include <string.h>

#include "serd_internal.h"

typedef struct {
	SerdNode name;
	SerdNode uri;
} SerdPrefix;

struct SerdEnvImpl {
	SerdPrefix* prefixes;
	size_t      n_prefixes;
};

SERD_API
SerdEnv*
serd_env_new()
{
	SerdEnv* env = malloc(sizeof(struct SerdEnvImpl));
	env->prefixes   = NULL;
	env->n_prefixes = 0;
	return env;
}

SERD_API
void
serd_env_free(SerdEnv* env)
{
	for (size_t i = 0; i < env->n_prefixes; ++i) {
		serd_node_free(&env->prefixes[i].name);
		serd_node_free(&env->prefixes[i].uri);
	}
	free(env->prefixes);
	free(env);
}

static inline SerdPrefix*
serd_env_find(const SerdEnv* env,
              const uint8_t* name,
              size_t         name_len)
{
	for (size_t i = 0; i < env->n_prefixes; ++i) {
		const SerdNode* const prefix_name = &env->prefixes[i].name;
		if (prefix_name->n_bytes == name_len + 1) {
			if (!memcmp(prefix_name->buf, name, name_len)) {
				return &env->prefixes[i];
			}
		}
	}
	return NULL;
}

SERD_API
void
serd_env_add(SerdEnv*        env,
             const SerdNode* name,
             const SerdNode* uri)
{
	assert(name && uri);
	SerdPrefix* const prefix = serd_env_find(env, name->buf, name->n_chars);
	if (prefix) {
		serd_node_free(&prefix->uri);
		prefix->uri = serd_node_copy(uri);
	} else {
		env->prefixes = realloc(env->prefixes,
		                        (++env->n_prefixes) * sizeof(SerdPrefix));
		env->prefixes[env->n_prefixes - 1].name = serd_node_copy(name);
		env->prefixes[env->n_prefixes - 1].uri  = serd_node_copy(uri);
	}
}

SERD_API
bool
serd_env_qualify(const SerdEnv*  env,
                 const SerdNode* uri,
                 SerdNode*       prefix_name,
                 SerdChunk*      suffix)
{
	for (size_t i = 0; i < env->n_prefixes; ++i) {
		const SerdNode* const prefix_uri = &env->prefixes[i].uri;
		if (uri->n_bytes >= prefix_uri->n_bytes) {
			if (!strncmp((const char*)uri->buf,
			             (const char*)prefix_uri->buf,
			             prefix_uri->n_bytes - 1)) {
				*prefix_name = env->prefixes[i].name;
				suffix->buf = uri->buf + prefix_uri->n_bytes - 1;
				suffix->len = uri->n_bytes - prefix_uri->n_bytes;
				return true;
			}
		}
	}
	return false;
}

SERD_API
SerdStatus
serd_env_expand(const SerdEnv*  env,
                const SerdNode* qname,
                SerdChunk*      uri_prefix,
                SerdChunk*      uri_suffix)
{
	const uint8_t* const colon = memchr(qname->buf, ':', qname->n_bytes);
	if (!colon) {
		return SERD_ERR_BAD_ARG;  // Illegal qname
	}

	const size_t            name_len = colon - qname->buf;
	const SerdPrefix* const prefix   = serd_env_find(env, qname->buf, name_len);
	if (prefix) {
		uri_prefix->buf = prefix->uri.buf;
		uri_prefix->len = prefix->uri.n_bytes - 1;
		uri_suffix->buf = colon + 1;
		uri_suffix->len = qname->n_bytes - (colon - qname->buf) - 2;
		return SERD_SUCCESS;
	}
	return SERD_ERR_NOT_FOUND;
}

SERD_API
void
serd_env_foreach(const SerdEnv* env,
                 SerdPrefixSink func,
                 void*          handle)
{
	for (size_t i = 0; i < env->n_prefixes; ++i) {
		func(handle,
		     &env->prefixes[i].name,
		     &env->prefixes[i].uri);
	}
}