/*

 * Copyright (c) 2006-2016 Kirill Simonov

 *

 * Permission is hereby granted, free of charge, to any person obtaining a copy of

 * this software and associated documentation files (the "Software"), to deal in

 * the Software without restriction, including without limitation the rights to

 * use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies

 * of the Software, and to permit persons to whom the Software is furnished to do

 * so, subject to the following conditions:

 *

 * The above copyright notice and this permission notice shall be included in all

 * copies or substantial portions of the Software.

 *

 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR

 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,

 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE

 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER

 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,

 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE

 * SOFTWARE.

 *

 */

#include "yaml_private.h"

/*

 * API functions.

 */

YAML_DECLARE(int)

yaml_parser_load(yaml_parser_t *parser, yaml_document_t *document);

/*

 * Error handling.

 */

static int

yaml_parser_set_composer_error(yaml_parser_t *parser,

        const char *problem, yaml_mark_t problem_mark);

static int

yaml_parser_set_composer_error_context(yaml_parser_t *parser,

        const char *context, yaml_mark_t context_mark,

        const char *problem, yaml_mark_t problem_mark);

/*

 * Alias handling.

 */

static int

yaml_parser_register_anchor(yaml_parser_t *parser,

        int index, yaml_char_t *anchor);

/*

 * Clean up functions.

 */

static void

yaml_parser_delete_aliases(yaml_parser_t *parser);

/*

 * Composer functions.

 */

static int

yaml_parser_load_document(yaml_parser_t *parser, yaml_event_t *first_event);

static int

yaml_parser_load_node(yaml_parser_t *parser, yaml_event_t *first_event);

static int

yaml_parser_load_alias(yaml_parser_t *parser, yaml_event_t *first_event);

static int

yaml_parser_load_scalar(yaml_parser_t *parser, yaml_event_t *first_event);

static int

yaml_parser_load_sequence(yaml_parser_t *parser, yaml_event_t *first_event);

static int

yaml_parser_load_mapping(yaml_parser_t *parser, yaml_event_t *first_event);

/*

 * Load the next document of the stream.

 */

YAML_DECLARE(int)

yaml_parser_load(yaml_parser_t *parser, yaml_document_t *document)

{

    yaml_event_t event;

    assert(parser);     /* Non-NULL parser object is expected. */

    assert(document);   /* Non-NULL document object is expected. */

    memset(document, 0, sizeof(yaml_document_t));

    if (!STACK_INIT(parser, document->nodes, INITIAL_STACK_SIZE))

        goto error;

    if (!parser->stream_start_produced) {

        if (!yaml_parser_parse(parser, &event)) goto error;

        assert(event.type == YAML_STREAM_START_EVENT);

                        /* STREAM-START is expected. */

    }

    if (parser->stream_end_produced) {

        return 1;

    }

    if (!yaml_parser_parse(parser, &event)) goto error;

    if (event.type == YAML_STREAM_END_EVENT) {

        return 1;

    }

    if (!STACK_INIT(parser, parser->aliases, INITIAL_STACK_SIZE))

        goto error;

    parser->document = document;

    if (!yaml_parser_load_document(parser, &event)) goto error;

    yaml_parser_delete_aliases(parser);

    parser->document = NULL;

    return 1;

error:

    yaml_parser_delete_aliases(parser);

    yaml_document_delete(document);

    parser->document = NULL;

    return 0;

}

/*

 * Set composer error.

 */

static int

yaml_parser_set_composer_error(yaml_parser_t *parser,

        const char *problem, yaml_mark_t problem_mark)

{

    parser->error = YAML_COMPOSER_ERROR;

    parser->problem = problem;

    parser->problem_mark = problem_mark;

    return 0;

}

/*

 * Set composer error with context.

 */

static int

yaml_parser_set_composer_error_context(yaml_parser_t *parser,

        const char *context, yaml_mark_t context_mark,

        const char *problem, yaml_mark_t problem_mark)

{

    parser->error = YAML_COMPOSER_ERROR;

    parser->context = context;

    parser->context_mark = context_mark;

    parser->problem = problem;

    parser->problem_mark = problem_mark;

    return 0;

}

/*

 * Delete the stack of aliases.

 */

static void

yaml_parser_delete_aliases(yaml_parser_t *parser)

{

    while (!STACK_EMPTY(parser, parser->aliases)) {

        yaml_free(POP(parser, parser->aliases).anchor);

    }

    STACK_DEL(parser, parser->aliases);

}

/*

 * Compose a document object.

 */

static int

yaml_parser_load_document(yaml_parser_t *parser, yaml_event_t *first_event)

{

    yaml_event_t event;

    assert(first_event->type == YAML_DOCUMENT_START_EVENT);

                        /* DOCUMENT-START is expected. */

    parser->document->version_directive

        = first_event->data.document_start.version_directive;

    parser->document->tag_directives.start

        = first_event->data.document_start.tag_directives.start;

    parser->document->tag_directives.end

        = first_event->data.document_start.tag_directives.end;

    parser->document->start_implicit

        = first_event->data.document_start.implicit;

    parser->document->start_mark = first_event->start_mark;

    if (!yaml_parser_parse(parser, &event)) return 0;

    if (!yaml_parser_load_node(parser, &event)) return 0;

    if (!yaml_parser_parse(parser, &event)) return 0;

    assert(event.type == YAML_DOCUMENT_END_EVENT);

                        /* DOCUMENT-END is expected. */

    parser->document->end_implicit = event.data.document_end.implicit;

    parser->document->end_mark = event.end_mark;

    return 1;

}

/*

 * Compose a node.

 */

static int

yaml_parser_load_node(yaml_parser_t *parser, yaml_event_t *first_event)

{

    switch (first_event->type) {

        case YAML_ALIAS_EVENT:

            return yaml_parser_load_alias(parser, first_event);

        case YAML_SCALAR_EVENT:

            return yaml_parser_load_scalar(parser, first_event);

        case YAML_SEQUENCE_START_EVENT:

            return yaml_parser_load_sequence(parser, first_event);

        case YAML_MAPPING_START_EVENT:

            return yaml_parser_load_mapping(parser, first_event);

        default:

            assert(0);  /* Could not happen. */

            return 0;

    }

    return 0;

}

/*

 * Add an anchor.

 */

static int

yaml_parser_register_anchor(yaml_parser_t *parser,

        int index, yaml_char_t *anchor)

{

    yaml_alias_data_t data;

    yaml_alias_data_t *alias_data;

    if (!anchor) return 1;

    data.anchor = anchor;

    data.index = index;

    data.mark = parser->document->nodes.start[index-1].start_mark;

    for (alias_data = parser->aliases.start;

            alias_data != parser->aliases.top; alias_data ++) {

        if (strcmp((char *)alias_data->anchor, (char *)anchor) == 0) {

            yaml_free(anchor);

            return yaml_parser_set_composer_error_context(parser,

                    "found duplicate anchor; first occurence",

                    alias_data->mark, "second occurence", data.mark);

        }

    }

    if (!PUSH(parser, parser->aliases, data)) {

        yaml_free(anchor);

        return 0;

    }

    return 1;

}

/*

 * Compose a node corresponding to an alias.

 */

static int

yaml_parser_load_alias(yaml_parser_t *parser, yaml_event_t *first_event)

{

    yaml_char_t *anchor = first_event->data.alias.anchor;

    yaml_alias_data_t *alias_data;

    for (alias_data = parser->aliases.start;

            alias_data != parser->aliases.top; alias_data ++) {

        if (strcmp((char *)alias_data->anchor, (char *)anchor) == 0) {

            yaml_free(anchor);

            return alias_data->index;

        }

    }

    yaml_free(anchor);

    return yaml_parser_set_composer_error(parser, "found undefined alias",

            first_event->start_mark);

}

/*

 * Compose a scalar node.

 */

static int

yaml_parser_load_scalar(yaml_parser_t *parser, yaml_event_t *first_event)

{

    yaml_node_t node;

    int index;

    yaml_char_t *tag = first_event->data.scalar.tag;

    if (!STACK_LIMIT(parser, parser->document->nodes, INT_MAX-1)) goto error;

    if (!tag || strcmp((char *)tag, "!") == 0) {

        yaml_free(tag);

        tag = yaml_strdup((yaml_char_t *)YAML_DEFAULT_SCALAR_TAG);

        if (!tag) goto error;

    }

    SCALAR_NODE_INIT(node, tag, first_event->data.scalar.value,

            first_event->data.scalar.length, first_event->data.scalar.style,

            first_event->start_mark, first_event->end_mark);

    if (!PUSH(parser, parser->document->nodes, node)) goto error;

    index = (int)(parser->document->nodes.top - parser->document->nodes.start);

    if (!yaml_parser_register_anchor(parser, index,

                first_event->data.scalar.anchor)) return 0;

    return index;

error:

    yaml_free(tag);

    yaml_free(first_event->data.scalar.anchor);

    yaml_free(first_event->data.scalar.value);

    return 0;

}

/*

 * Compose a sequence node.

 */

static int

yaml_parser_load_sequence(yaml_parser_t *parser, yaml_event_t *first_event)

{

    yaml_event_t event;

    yaml_node_t node;

    struct {

        yaml_node_item_t *start;

        yaml_node_item_t *end;

        yaml_node_item_t *top;

    } items = { NULL, NULL, NULL };

    int index, item_index;

    yaml_char_t *tag = first_event->data.sequence_start.tag;

    if (!STACK_LIMIT(parser, parser->document->nodes, INT_MAX-1)) goto error;

    if (!tag || strcmp((char *)tag, "!") == 0) {

        yaml_free(tag);

        tag = yaml_strdup((yaml_char_t *)YAML_DEFAULT_SEQUENCE_TAG);

        if (!tag) goto error;

    }

    if (!STACK_INIT(parser, items, INITIAL_STACK_SIZE)) goto error;

    SEQUENCE_NODE_INIT(node, tag, items.start, items.end,

            first_event->data.sequence_start.style,

            first_event->start_mark, first_event->end_mark);

    if (!PUSH(parser, parser->document->nodes, node)) goto error;

    index = (int)(parser->document->nodes.top - parser->document->nodes.start);

    if (!yaml_parser_register_anchor(parser, index,

                first_event->data.sequence_start.anchor)) return 0;

    if (!yaml_parser_parse(parser, &event)) return 0;

    while (event.type != YAML_SEQUENCE_END_EVENT) {

        if (!STACK_LIMIT(parser,

                    parser->document->nodes.start[index-1].data.sequence.items,

                    INT_MAX-1)) return 0;

        item_index = yaml_parser_load_node(parser, &event);

        if (!item_index) return 0;

        if (!PUSH(parser,

                    parser->document->nodes.start[index-1].data.sequence.items,

                    item_index)) return 0;

        if (!yaml_parser_parse(parser, &event)) return 0;

    }

    parser->document->nodes.start[index-1].end_mark = event.end_mark;

    return index;

error:

    yaml_free(tag);

    yaml_free(first_event->data.sequence_start.anchor);

    return 0;

}

/*

 * Compose a mapping node.

 */

static int

yaml_parser_load_mapping(yaml_parser_t *parser, yaml_event_t *first_event)

{

    yaml_event_t event;

    yaml_node_t node;

    struct {

        yaml_node_pair_t *start;

        yaml_node_pair_t *end;

        yaml_node_pair_t *top;

    } pairs = { NULL, NULL, NULL };

    int index;

    yaml_node_pair_t pair;

    yaml_char_t *tag = first_event->data.mapping_start.tag;

    if (!STACK_LIMIT(parser, parser->document->nodes, INT_MAX-1)) goto error;

    if (!tag || strcmp((char *)tag, "!") == 0) {

        yaml_free(tag);

        tag = yaml_strdup((yaml_char_t *)YAML_DEFAULT_MAPPING_TAG);

        if (!tag) goto error;

    }

    if (!STACK_INIT(parser, pairs, INITIAL_STACK_SIZE)) goto error;

    MAPPING_NODE_INIT(node, tag, pairs.start, pairs.end,

            first_event->data.mapping_start.style,

            first_event->start_mark, first_event->end_mark);

    if (!PUSH(parser, parser->document->nodes, node)) goto error;

    index = (int)(parser->document->nodes.top - parser->document->nodes.start);

    if (!yaml_parser_register_anchor(parser, index,

                first_event->data.mapping_start.anchor)) return 0;

    if (!yaml_parser_parse(parser, &event)) return 0;

    while (event.type != YAML_MAPPING_END_EVENT) {

        if (!STACK_LIMIT(parser,

                    parser->document->nodes.start[index-1].data.mapping.pairs,

                    INT_MAX-1)) return 0;

        pair.key = yaml_parser_load_node(parser, &event);

        if (!pair.key) return 0;

        if (!yaml_parser_parse(parser, &event)) return 0;

        pair.value = yaml_parser_load_node(parser, &event);

        if (!pair.value) return 0;

        if (!PUSH(parser,

                    parser->document->nodes.start[index-1].data.mapping.pairs,

                    pair)) return 0;

        if (!yaml_parser_parse(parser, &event)) return 0;

    }

    parser->document->nodes.start[index-1].end_mark = event.end_mark;

    return index;

error:

    yaml_free(tag);

    yaml_free(first_event->data.mapping_start.anchor);

    return 0;

}