#include "cache.h"
#include "color.h"
#include "config.h"
#include "sideband.h"
#include "help.h"

struct keyword_entry {
        /*
         * We use keyword as config key so it should be a single alphanumeric word.
         */
        const char *keyword;
        char color[COLOR_MAXLEN];
};

static struct keyword_entry keywords[] = {
        { "hint",       GIT_COLOR_YELLOW },
        { "warning",    GIT_COLOR_BOLD_YELLOW },
        { "success",    GIT_COLOR_BOLD_GREEN },
        { "error",      GIT_COLOR_BOLD_RED },
};

/* Returns a color setting (GIT_COLOR_NEVER, etc). */
static int use_sideband_colors(void)
{
        static int use_sideband_colors_cached = -1;

        const char *key = "color.remote";
        struct strbuf sb = STRBUF_INIT;
        char *value;
        int i;

        if (use_sideband_colors_cached >= 0)
                return use_sideband_colors_cached;

        if (!git_config_get_string(key, &value)) {
                use_sideband_colors_cached = git_config_colorbool(key, value);
        } else if (!git_config_get_string("color.ui", &value)) {
                use_sideband_colors_cached = git_config_colorbool("color.ui", value);
        } else {
                use_sideband_colors_cached = GIT_COLOR_AUTO;
        }

        for (i = 0; i < ARRAY_SIZE(keywords); i++) {
                strbuf_reset(&sb);
                strbuf_addf(&sb, "%s.%s", key, keywords[i].keyword);
                if (git_config_get_string(sb.buf, &value))
                        continue;
                if (color_parse(value, keywords[i].color))
                        continue;
        }
        strbuf_release(&sb);
        return use_sideband_colors_cached;
}

void list_config_color_sideband_slots(struct string_list *list, const char *prefix)
{
        int i;

        for (i = 0; i < ARRAY_SIZE(keywords); i++)
                list_config_item(list, prefix, keywords[i].keyword);
}

/*
 * Optionally highlight one keyword in remote output if it appears at the start
 * of the line. This should be called for a single line only, which is
 * passed as the first N characters of the SRC array.
 *
 * NEEDSWORK: use "size_t n" instead for clarity.
 */
static void maybe_colorize_sideband(struct strbuf *dest, const char *src, int n)
{
        int i;

        if (!want_color_stderr(use_sideband_colors())) {
                strbuf_add(dest, src, n);
                return;
        }

        while (0 < n && isspace(*src)) {
                strbuf_addch(dest, *src);
                src++;
                n--;
        }

        for (i = 0; i < ARRAY_SIZE(keywords); i++) {
                struct keyword_entry *p = keywords + i;
                int len = strlen(p->keyword);

                if (n <= len)
                        continue;
                /*
                 * Match case insensitively, so we colorize output from existing
                 * servers regardless of the case that they use for their
                 * messages. We only highlight the word precisely, so
                 * "successful" stays uncolored.
                 */
                if (!strncasecmp(p->keyword, src, len) && !isalnum(src[len])) {
                        strbuf_addstr(dest, p->color);
                        strbuf_add(dest, src, len);
                        strbuf_addstr(dest, GIT_COLOR_RESET);
                        n -= len;
                        src += len;
                        break;
                }
        }

        strbuf_add(dest, src, n);
}


#define DISPLAY_PREFIX "remote: "

#define ANSI_SUFFIX "\033[K"
#define DUMB_SUFFIX "        "

int demultiplex_sideband(const char *me, char *buf, int len,
                         int die_on_error,
                         struct strbuf *scratch,
                         enum sideband_type *sideband_type)
{
        static const char *suffix;
        const char *b, *brk;
        int band;

        if (!suffix) {
                if (isatty(2) && !is_terminal_dumb())
                        suffix = ANSI_SUFFIX;
                else
                        suffix = DUMB_SUFFIX;
        }

        if (len == 0) {
                *sideband_type = SIDEBAND_FLUSH;
                goto cleanup;
        }
        if (len < 1) {
                strbuf_addf(scratch,
                            "%s%s: protocol error: no band designator",
                            scratch->len ? "\n" : "", me);
                *sideband_type = SIDEBAND_PROTOCOL_ERROR;
                goto cleanup;
        }
        band = buf[0] & 0xff;
        buf[len] = '\0';
        len--;
        switch (band) {
        case 3:
                if (die_on_error)
                        die("remote error: %s", buf + 1);
                strbuf_addf(scratch, "%s%s", scratch->len ? "\n" : "",
                            DISPLAY_PREFIX);
                maybe_colorize_sideband(scratch, buf + 1, len);

                *sideband_type = SIDEBAND_REMOTE_ERROR;
                break;
        case 2:
                b = buf + 1;

                /*
                 * Append a suffix to each nonempty line to clear the
                 * end of the screen line.
                 *
                 * The output is accumulated in a buffer and
                 * each line is printed to stderr using
                 * write(2) to ensure inter-process atomicity.
                 */
                while ((brk = strpbrk(b, "\n\r"))) {
                        int linelen = brk - b;

                        if (!scratch->len)
                                strbuf_addstr(scratch, DISPLAY_PREFIX);
                        if (linelen > 0) {
                                maybe_colorize_sideband(scratch, b, linelen);
                                strbuf_addstr(scratch, suffix);
                        }

                        strbuf_addch(scratch, *brk);
                        xwrite(2, scratch->buf, scratch->len);
                        strbuf_reset(scratch);

                        b = brk + 1;
                }

                if (*b) {
                        strbuf_addstr(scratch, scratch->len ?
                                    "" : DISPLAY_PREFIX);
                        maybe_colorize_sideband(scratch, b, strlen(b));
                }
                return 0;
        case 1:
                *sideband_type = SIDEBAND_PRIMARY;
                break;
        default:
                strbuf_addf(scratch, "%s%s: protocol error: bad band #%d",
                            scratch->len ? "\n" : "", me, band);
                *sideband_type = SIDEBAND_PROTOCOL_ERROR;
                break;
        }

cleanup:
        if (die_on_error && *sideband_type == SIDEBAND_PROTOCOL_ERROR)
                die("%s", scratch->buf);
        if (scratch->len) {
                strbuf_addch(scratch, '\n');
                xwrite(2, scratch->buf, scratch->len);
        }
        strbuf_release(scratch);
        return 1;
}

/*
 * fd is connected to the remote side; send the sideband data
 * over multiplexed packet stream.
 */
void send_sideband(int fd, int band, const char *data, ssize_t sz, int packet_max)
{
        const char *p = data;

        while (sz) {
                unsigned n;
                char hdr[5];

                n = sz;
                if (packet_max - 5 < n)
                        n = packet_max - 5;
                if (0 <= band) {
                        xsnprintf(hdr, sizeof(hdr), "%04x", n + 5);
                        hdr[4] = band;
                        write_or_die(fd, hdr, 5);
                } else {
                        xsnprintf(hdr, sizeof(hdr), "%04x", n + 4);
                        write_or_die(fd, hdr, 4);
                }
                write_or_die(fd, p, n);
                p += n;
                sz -= n;
        }
}