path: root/src/html/html.c

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

#include "cmark.h"
#include "debug.h"
#include "html/houdini.h"

typedef struct RenderStack {
    struct RenderStack *previous;
    char* literal;
    union {
    node_inl *inl;
    node_block *block;
    } next_sibling;
    bool tight;
} render_stack;

static void free_render_stack(render_stack * rstack)
{
    render_stack * tempstack;
    while (rstack) {
    tempstack = rstack;
    rstack = rstack->previous;
    free(tempstack);
    }
}

static render_stack* push_inline(render_stack* rstack,
                 node_inl* inl,
                 char* literal)
{
    render_stack* newstack;
    newstack = (render_stack*)malloc(sizeof(render_stack));
    if (newstack == NULL) {
    return NULL;
    }
    newstack->previous = rstack;
    newstack->next_sibling.inl = inl;
    newstack->literal = literal;
    return newstack;
}

static render_stack* push_block(render_stack* rstack,
                node_block* block,
                char* literal,
                bool tight)
{
    render_stack* newstack;
    newstack = (render_stack*)malloc(sizeof(render_stack));
    if (newstack == NULL) {
    return NULL;
    }
    newstack->previous = rstack;
    newstack->next_sibling.block = block;
    newstack->literal = literal;
    newstack->tight = tight;
    return newstack;
}

static render_stack* pop_render_stack(render_stack* rstack)
{
    render_stack* top = rstack;

    if (rstack == NULL) {
    return NULL;
    }
    rstack = rstack->previous;
    top->previous = NULL;
    free_render_stack(top);
    return rstack;
}

// Functions to convert node_block and inline lists to HTML strings.

static void escape_html(strbuf *dest, const unsigned char *source, int length)
{
    if (length < 0)
        length = strlen((char *)source);

    houdini_escape_html0(dest, source, (size_t)length, 0);
}

static void escape_href(strbuf *dest, const unsigned char *source, int length)
{
    if (length < 0)
        length = strlen((char *)source);

    houdini_escape_href(dest, source, (size_t)length);
}

static inline void cr(strbuf *html)
{
    if (html->size && html->ptr[html->size - 1] != '\n')
        strbuf_putc(html, '\n');
}

// Convert an inline list to HTML.  Returns 0 on success, and sets result.
static void inlines_to_plain_html(strbuf *html, node_inl* ils)
{
    node_inl* children;
    render_stack* rstack = NULL;

    while(ils != NULL) {
            children = NULL;
        switch(ils->tag) {
            case INL_STRING:
            case INL_CODE:
                case INL_RAW_HTML:
                escape_html(html, ils->content.literal.data, ils->content.literal.len);
                break;

            case INL_LINEBREAK:
            case INL_SOFTBREAK:
                strbuf_putc(html, '\n');
                break;

            case INL_LINK:
            case INL_IMAGE:
                children = ils->content.inlines;
                rstack = push_inline(rstack, ils->next, "");
                break;

            case INL_STRONG:
            case INL_EMPH:
                children = ils->content.inlines;
                rstack = push_inline(rstack, ils->next, "");
                break;
        }
        if (children) {
            ils = children;
        } else {
            ils = ils->next;
        }
        while (ils == NULL && rstack != NULL) {
            strbuf_puts(html, rstack->literal);
            ils = rstack->next_sibling.inl;
            rstack = pop_render_stack(rstack);
        }
    }

    free_render_stack(rstack);
}


// Convert an inline list to HTML.  Returns 0 on success, and sets result.
static void inlines_to_html(strbuf *html, node_inl* ils)
{
    node_inl* children;
    render_stack* rstack = NULL;

    while(ils != NULL) {
            children = NULL;
        switch(ils->tag) {
            case INL_STRING:
                escape_html(html, ils->content.literal.data, ils->content.literal.len);
                break;

            case INL_LINEBREAK:
                strbuf_puts(html, "<br />\n");
                break;

            case INL_SOFTBREAK:
                strbuf_putc(html, '\n');
                break;

            case INL_CODE:
                strbuf_puts(html, "<code>");
                escape_html(html, ils->content.literal.data, ils->content.literal.len);
                strbuf_puts(html, "</code>");
                break;

            case INL_RAW_HTML:
                strbuf_put(html,
                        ils->content.literal.data,
                        ils->content.literal.len);
                break;

            case INL_LINK:
                strbuf_puts(html, "<a href=\"");
                if (ils->content.linkable.url)
                    escape_href(html, ils->content.linkable.url, -1);

                if (ils->content.linkable.title) {
                    strbuf_puts(html, "\" title=\"");
                    escape_html(html, ils->content.linkable.title, -1);
                }

                strbuf_puts(html, "\">");
                children = ils->content.inlines;
                rstack = push_inline(rstack, ils->next, "</a>");
                break;

            case INL_IMAGE:
                strbuf_puts(html, "<img src=\"");
                if (ils->content.linkable.url)
                    escape_href(html, ils->content.linkable.url, -1);

                strbuf_puts(html, "\" alt=\"");
                inlines_to_plain_html(html, ils->content.inlines);

                if (ils->content.linkable.title) {
                    strbuf_puts(html, "\" title=\"");
                    escape_html(html, ils->content.linkable.title, -1);
                }

                strbuf_puts(html, "\"/>");
                break;

            case INL_STRONG:
                strbuf_puts(html, "<strong>");
                children = ils->content.inlines;
                rstack = push_inline(rstack, ils->next, "</strong>");
                break;

            case INL_EMPH:
                strbuf_puts(html, "<em>");
                children = ils->content.inlines;
                rstack = push_inline(rstack, ils->next, "</em>");
                break;
        }
        if (children) {
            ils = children;
        } else {
            ils = ils->next;
        }
        while (ils == NULL && rstack != NULL) {
            strbuf_puts(html, rstack->literal);
            ils = rstack->next_sibling.inl;
            rstack = pop_render_stack(rstack);
        }
    }

    free_render_stack(rstack);
}

// Convert a node_block list to HTML.  Returns 0 on success, and sets result.
static void blocks_to_html(strbuf *html, node_block *b, bool tight)
{
    struct ListData *data;

    while(b != NULL) {
        switch(b->tag) {
            case BLOCK_DOCUMENT:
                blocks_to_html(html, b->children, false);
                break;

            case BLOCK_PARAGRAPH:
                if (tight) {
                    inlines_to_html(html, b->inline_content);
                } else {
                    cr(html);
                    strbuf_puts(html, "<p>");
                    inlines_to_html(html, b->inline_content);
                    strbuf_puts(html, "</p>\n");
                }
                break;

            case BLOCK_BQUOTE:
                cr(html);
                strbuf_puts(html, "<blockquote>\n");
                blocks_to_html(html, b->children, false);
                strbuf_puts(html, "</blockquote>\n");
                break;

            case BLOCK_LIST_ITEM:
                cr(html);
                strbuf_puts(html, "<li>");
                blocks_to_html(html, b->children, tight);
                strbuf_trim(html); /* TODO: rtrim */
                strbuf_puts(html, "</li>\n");
                break;

            case BLOCK_LIST:
                // make sure a list starts at the beginning of the line:
                cr(html);
                data = &(b->as.list);

                if (data->start > 1) {
                    strbuf_printf(html, "<%s start=\"%d\">\n",
                            data->list_type == bullet ? "ul" : "ol",
                            data->start);
                } else {
                    strbuf_puts(html, data->list_type == bullet ? "<ul>\n" : "<ol>\n");
                }

                blocks_to_html(html, b->children, data->tight);
                strbuf_puts(html, data->list_type == bullet ? "</ul>" : "</ol>");
                strbuf_putc(html, '\n');
                break;

            case BLOCK_ATX_HEADER:
            case BLOCK_SETEXT_HEADER:
                cr(html);
                strbuf_printf(html, "<h%d>", b->as.header.level);
                inlines_to_html(html, b->inline_content);
                strbuf_printf(html, "</h%d>\n", b->as.header.level);
                break;

            case BLOCK_INDENTED_CODE:
            case BLOCK_FENCED_CODE:
                cr(html);

                strbuf_puts(html, "<pre><code");

                if (b->tag == BLOCK_FENCED_CODE) {
                    strbuf *info = &b->as.code.info;

                    if (strbuf_len(info) > 0) {
                        int first_tag = strbuf_strchr(info, ' ', 0);
                        if (first_tag < 0)
                            first_tag = strbuf_len(info);

                        strbuf_puts(html, " class=\"language-");
                        escape_html(html, info->ptr, first_tag);
                        strbuf_putc(html, '"');
                    }
                }

                strbuf_putc(html, '>');
                escape_html(html, b->string_content.ptr, b->string_content.size);
                strbuf_puts(html, "</code></pre>\n");
                break;

            case BLOCK_HTML:
                strbuf_put(html, b->string_content.ptr, b->string_content.size);
                break;

            case BLOCK_HRULE:
                strbuf_puts(html, "<hr />\n");
                break;

            case BLOCK_REFERENCE_DEF:
                break;

            default:
                assert(false);
        }

        b = b->next;
    }
}

void cmark_render_html(strbuf *html, node_block *root)
{
    blocks_to_html(html, root, false);
}