#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <err.h>
#include <ctype.h>
#include <template.h>

void
usage(void)
{
    printf(
        "libtemplate formatter usage\n"
        "Usage:\n"
        "    tpl-formatter\n");
}

/*
 * A custom formatter:
 * - render json string in upper case.
 */
void
formatter_upper(struct json *json, struct writer *writer)
{
    if (json_is_str(json)) {
        char *value = json_get_value_str(json);
        for (; *value != '\0'; value++) {
            char c = (char) toupper(*value);
            writer_write(writer, &c, 1);
        }
    }
}

int
main(int argc, char *argv[])
{
    if (argc > 1 && strcmp(argv[1], "-h") == 0) {
        usage();
        return EXIT_SUCCESS;
    }

    /*
     * Intantiate a new template,
     * and register a custom formatter.
     */
    struct template *tpl = template_new();
    template_set_formatter(tpl, "upper", formatter_upper);

    /*
     * Template string to parse and render:
     * - a variable using the html encoder formatter
     * - a variable using the url encoder formatter
     * - a variable using a custom formatter
     */
    const char *tpl_string =
        "html encoder formatter:\n"
        " - before: {{html}}\n"
        " - after : {{& html}}\n\n"
        "url encoder formatter:\n"
        " - before: {{url}}\n"
        " - after : {{% url}}\n\n"
        "custom (upper) formatter:\n"
        " - before: {{word}}\n"
        " - after : {{f:upper word}}\n\n";

    /*
     * Create a JSON object to feed the template
     */
    struct json *json = json_obj_addv(NULL,
            "html", json_str("<b>bob & son</b>"),
            "url", json_str("http://foutaise.org"),
            "word", json_str("foutaise"),
            NULL);

    /*
     * Parse the string template,
     * then render output using json data
     */
    if (! template_parse_string(tpl, tpl_string))
        errx(1, "%s", template_error_msg(tpl));
    template_render(tpl, json);

    /*
     * Cleanup
     */
    template_free(tpl);
    json_free(json);

    return EXIT_SUCCESS;
}