/* aya.c - Generates a documentation page for a Parsee function
 * ============================================================
 * Not hdoc because I hate hdoc!!!!!!111!!!!!!1!!!!11111!!!
 * TODO: Aya is currently incomplete. Sorry, not sorry.
 *
 * Under CC0, as its a rather useful example of a KappaChat tool.
 * See LICENSE for more information about Parsee's licensing. */

#include <Cytoplasm/HeaderParser.h>
#include <Cytoplasm/HashMap.h>
#include <Cytoplasm/Memory.h>
#include <Cytoplasm/Stream.h>
#include <Cytoplasm/Args.h>
#include <Cytoplasm/Log.h>
#include <Cytoplasm/Str.h>
#include <Cytoplasm/Uri.h>

#include <stdlib.h>
#include <string.h>
#include <ctype.h>

typedef struct AyadocComment {
    /* TODO: Descriptions are a bit more advanced than a raw string.
     * Only because you have to deal with the {value} format. */
    char *description;

    /* Some notes are more advanced (see Returns, Modifies, See-Also, ...) */
    HashMap *notes;
} AyadocComment;

static void
FreeAyadoc(AyadocComment *comment)
{
    char *key, *value;
    if (!comment)
    {
        return;
    }

    Free(comment->description);
    while (HashMapIterate(comment->notes, &key, (void **) &value))
    {
        Free(value);
    }
    HashMapFree(comment->notes);

    Free(comment);
}
static AyadocComment *
ParseAyadoc(char *raw)
{
    AyadocComment *ret;
    char *start, *line_break;
    bool end_of_text = false;
    bool parsing_notes = false;
    if (!raw)
    {
        return NULL;
    }
    ret = Malloc(sizeof(*ret));
    ret->notes = HashMapCreate();
    ret->description = NULL;

    start = raw;
    while (!end_of_text)
    {
        char *line_content = NULL, *temporary = NULL;
        char *index_ptr;
        if (!(line_break = strchr(start, '\n')))
        {
            end_of_text = true;

            /* Points to the EOF. I am using strchr because we need to 
             * defer the {end_of_text}. */
            line_break = start + strlen(start);
        }

        if (start >= line_break)
        {
            break;
        }

        if (!strncmp(start, " *", 2) || !strncmp(start, "*", 1))
        {
            start += 1 + (*start == ' ');
            while (start && isspace(*start))
            {
                start++;
            }
        }

        line_content = StrDuplicate("");
        for (index_ptr = start; index_ptr < line_break; index_ptr++)
        {
            char char_buffer[2] = { *index_ptr, '\0' };

            temporary = line_content;
            line_content = StrConcat(2, line_content, char_buffer);
            Free(temporary);
        }

        if (!strncmp(line_content, "---", 3))
        {
            parsing_notes = true;

            goto line_end;
        }

        if (parsing_notes)
        {
            char *del = strchr(line_content, ':');
            char *val = del + 1;
            if (del && strlen(del) >= 1)
            {
                while (*val && isspace(*val))
                {
                    val++;
                }
            }
            if (del)
            {
                *del = '\0';
            }
            HashMapSet(ret->notes, line_content, StrDuplicate(val));
            goto line_end;
        }

        temporary = ret->description;
        ret->description = StrConcat(3, ret->description, line_content, "\n");
        Free(temporary);
line_end:
        Free(line_content);
        start = line_break + 1;
    }

    return ret;
}

static void
HandleReturnValue(Stream *out, AyadocComment *aya, HeaderDeclaration d, char *field)
{
    char *tag_del = NULL;
    if (StrEquals(field, "NOTHING"))
    {
        StreamPrintf(out, "<span class='rets-none'>nothing</span>");
        return;
    }
    else if (StrEquals(field, "NORETURN"))
    {
        StreamPrintf(out, "<span class='rets-exit'>doesn't return in the thread</span>");
        return;
    }

    if ((tag_del = strchr(field, '[')))
    {
        /* We're free to edit field, as it is in the heap */
        *tag_del = '\0';
    }

    /* Already write the field */
    StreamPrintf(out, " <span class='rets-span'>%s</span>", field);

    if (tag_del)
    {
        /* Locate the last ]. */
        char *end_tags = strrchr(++tag_del, ']');
        if (!end_tags)
        {
            end_tags = tag_del + strlen(tag_del);
        }

        *end_tags = '\0';
        if (StrEquals(tag_del, "LA:HEAP") ||
            StrEquals(tag_del, "HEAP"))
        {
            StreamPrintf(out, " <span class='rets-la'>(stored in the heap)</span>");
            return;
        }
        else if (!strncmp(tag_del, "LA:", 3))
        {
            tag_del += 3;
        }
        StreamPrintf(out, " <span class='rets-la'>(stored along %s)</span>", tag_del);
    }
}
static void
HandleSeeValue(Stream *out, AyadocComment *aya, HeaderDeclaration d, char *field)
{
    Uri *uri = UriParse(field);
    if (uri)
    {
        StreamPrintf(out, 
            "<a class='aya-see-field' href='%s'>%s</a>", 
            field, uri->host
        );
        UriFree(uri);
        return;
    }
    StreamPrintf(out, 
        "<a href='#fdiv-%s' class='aya-see-field'>%s</a>", 
        field, field
    );
}
#define SplitBy(sym, cb, del_str) \
    char *start_of_arg = val, *separator = NULL; \
    bool end_of_field = false; \
 \
    while (!end_of_field) \
    { \
        char *temporary, *field = NULL, *index; \
        char *last_char; \
        while (*start_of_arg && isspace(*start_of_arg)) \
        { \
            start_of_arg++; \
        } \
        if (!(separator = strchr(start_of_arg, sym))) \
        { \
            end_of_field = true; \
            separator = start_of_arg + strlen(start_of_arg); \
        } \
        if (start_of_arg >= separator) \
        { \
            break; \
        } \
 \
        /* Trim out spaces */ \
        last_char = separator - 1; \
        while (*last_char && isspace(*last_char)) \
        { \
            last_char--; \
        } \
 \
        field = StrDuplicate(""); \
        for (index = start_of_arg; index <= last_char; index++) \
        { \
            char buffer[2] = { *index, '\0' }; \
             \
            temporary = field; \
            field = StrConcat(2, field, buffer); \
            Free(temporary); \
        } \
 \
        /* Process the field */ \
        cb(out, ayadoc, decl, field); \
 \
        if (!end_of_field) \
        { \
            StreamPrintf(out, del_str); \
        } \
 \
        Free(field); \
        start_of_arg = separator + 1; \
    }

static void
GenerateReturns(Stream *out, AyadocComment *ayadoc, HeaderDeclaration decl, char *val)
{
    SplitBy('|', HandleReturnValue, " <strong>or</strong> ");
}
static void
GenerateSee(Stream *out, AyadocComment *ayadoc, HeaderDeclaration decl, char *val)
{
    SplitBy(',', HandleSeeValue, ", ");
}
#undef SplitBy

static void
GenerateHTML(Stream *out, AyadocComment *ayadoc, HeaderDeclaration decl)
{
    if (!out || !ayadoc)
    {
        return;
    }
  
    StreamPrintf(out, "<div id='fdiv-%s'>", decl.name);
    {
        StreamPrintf(out, "<hr/>");

        StreamPrintf(out, "<h3>Signature</h3>");
        StreamPrintf(out, "<div id='sdiv-%s'>", decl.name);
        {
            char *attr, *value;
            StreamPrintf(out, "<code>");
            {
                StreamPrintf(out, "<span class='aya-return'>");
                StreamPrintf(out, "%s", decl.returnType);
                StreamPrintf(out, "</span><br/>");
            }
            {
                size_t i, args = ArraySize(decl.args);
                StreamPrintf(out, "<span class='aya-name'>");
                StreamPrintf(out, "<strong>%s</strong>", decl.name);
                StreamPrintf(out, "</span>");
                StreamPrintf(out, "(");

                for (i = 0; i < args; i++)
                {
                    char *arg = ArrayGet(decl.args, i);

                    StreamPrintf(out, "<span class='aya-arg'>");
                    StreamPrintf(out, "%s", arg);
                    StreamPrintf(out, "</span>");

                    if (i != args - 1)
                    {
                        StreamPrintf(out, ", ");
                    }
                }
                StreamPrintf(out, ");");
            }
            StreamPrintf(out, "</code>");
            
            StreamPrintf(out, "<h3>Description</h3>");
            /* TODO: Pretty-print {}s by resolving from context. 
             * We don't make the input HTML-safe, aside from newlines as 
             * BR tags. */
            StreamPrintf(
                out, 
                "<p class='aya-desc'>%s</p>", 
                ayadoc->description ? 
                ayadoc->description :
                "<span class='aya-ndesc'>"
                    "(no description given)"
                "</span>"
            );

            /* Extra fields */
            while (HashMapIterate(ayadoc->notes, &attr, (void **) &value))
            {
                if (StrEquals(attr, "Returns"))
                {
                    StreamPrintf(out, "<div class='aya-pret' id='pret-%s'>", decl.name);
                    StreamPrintf(out, "<h2>Returns</h2>");
                    GenerateReturns(out, ayadoc, decl, value);
                    StreamPrintf(out, "</div>");
                    StreamFlush(out);
                    continue;
                }
                else if (StrEquals(attr, "See-Also"))
                {
                    StreamPrintf(out, "<div class='aya-see' id='see-%s'>", decl.name);
                    StreamPrintf(out, "<h2>See also</h2>");
                    GenerateSee(out, ayadoc, decl, value);
                    StreamPrintf(out, "</div>");
                    StreamFlush(out);
                    continue;
                }
                else if (StrEquals(attr, "Thrasher"))
                {
                    StreamPrintf(out, "<p class='aya-free' id='free-%s'>", decl.name);
                    StreamPrintf(out, "<strong>This function may be destroyed with ");
                    StreamPrintf(out, "<code><a href='#fdiv-%s'>%s</a></code>", value, value);
                    StreamPrintf(out, "</strong></p>");
                    StreamFlush(out);
                    continue;
                }
            }
            
        }
        StreamPrintf(out, "</div>");
    }
    StreamPrintf(out, "</div>");
    StreamFlush(out);
}

int
Main(Array *args, HashMap *env)
{
    ArgParseState state;
    int flag;

    char *header = NULL, *xhtml = NULL, *css = NULL;
    char *project = "Ayaya!";
    Stream *input, *output;
    bool help = false;

    ArgParseStateInit(&state);
    while ((flag = ArgParse(&state, args, "i:o:p:C:h")) != -1)
    {
        switch (flag)
        {
            case 'i':
                header = state.optArg;
                break;
            case 'o':
                xhtml = state.optArg;
                break;
            case 'C':
                css = state.optArg;
                break;
            case 'p':
                project = state.optArg;
                break;
            case 'h':
                help = true;
                break;
        }
    }

    if (!header || !xhtml || help)
    {
        Log(help ? LOG_INFO : LOG_ERR, 
            "Usage: %s "
                "-i [C header file] "
                "-o [Generated Aya HTML] "
                "-p {project name} "
                "-C {CSS stylefile}", 
            ArrayGet(args, 0)
        );
        return EXIT_FAILURE;
    }
    input = StreamOpen(header, "r");
    output = StreamOpen(xhtml, "w");

    StreamPrintf(output, "<!DOCTYPE html>");
    StreamPrintf(output, "<html>");

    StreamPrintf(output, "<head>");
    if (css)
    {
        Stream *css_stream = StreamOpen(css, "r");
        StreamPrintf(output, "<style>");
        StreamCopy(css_stream, output);
        StreamPrintf(output, "</style>");
        StreamClose(css_stream);
    }
    StreamPrintf(output, "</head>");

    StreamPrintf(output, "<body>");
    StreamPrintf(output, "<center><h1>%s: %s</h1></center>", project, header);
    StreamPrintf(output, "<br/>");
    /* TODO */
    {
        AyadocComment *comm = NULL;
        HeaderExpr expression = { 0 };
        while (true)
        {
            HeaderDeclaration decl;
            bool raw_put = false;

            HeaderParse(input, &expression);
            if (expression.type == HP_EOF)
            {
                break;
            }

            switch (expression.type)
            {
                case HP_COMMENT:
                    if (strncmp(expression.data.text, "*", 1) &&
                        strncmp(expression.data.text, "-*", 2))
                    {
                        break;
                    }
                    if (!strncmp(expression.data.text, "-*", 2))
                    {
                        raw_put = true;
                    }
                    if (comm)
                    {
                        FreeAyadoc(comm);
                    }
                    comm = ParseAyadoc(expression.data.text + !!raw_put);
                    if (raw_put)
                    {
                        StreamPrintf(output, "<p>");
                        StreamPrintf(output, comm->description);
                        StreamPrintf(output, "</p>");

                        FreeAyadoc(comm);
                        comm = NULL;
                    }
                    break;
                case HP_DECLARATION:
                    if (!comm)
                    {
                        break;
                    }
                    decl = expression.data.declaration;
                    GenerateHTML(output, comm, decl);
                    FreeAyadoc(comm);
                    comm = NULL;
                default:
                    break;
            }
        }
    }
    StreamPrintf(output, "</body>");

    StreamPrintf(output, "</html>");

    StreamClose(output);
    StreamClose(input);
    return EXIT_SUCCESS;
}