/*
 * GIT - The information manager from hell
 *
 * Copyright (C) Linus Torvalds, 2005
 */
#include "git-compat-util.h"
#include "cache.h"

static FILE *error_handle;
static int tweaked_error_buffering;

void vreportf(const char *prefix, const char *err, va_list params)
{
        FILE *fh = error_handle ? error_handle : stderr;

        fflush(fh);
        if (!tweaked_error_buffering) {
                setvbuf(fh, NULL, _IOLBF, 0);
                tweaked_error_buffering = 1;
        }

        fputs(prefix, fh);
        vfprintf(fh, err, params);
        fputc('\n', fh);
}

static NORETURN void usage_builtin(const char *err, va_list params)
{
        vreportf("usage: ", err, params);
        exit(129);
}

static NORETURN void die_builtin(const char *err, va_list params)
{
        vreportf("fatal: ", err, params);
        exit(128);
}

static void error_builtin(const char *err, va_list params)
{
        vreportf("error: ", err, params);
}

static void warn_builtin(const char *warn, va_list params)
{
        vreportf("warning: ", warn, params);
}

static int die_is_recursing_builtin(void)
{
        static int dying;
        return dying++;
}

/* If we are in a dlopen()ed .so write to a global variable would segfault
 * (ugh), so keep things static. */
static NORETURN_PTR void (*usage_routine)(const char *err, va_list params) = usage_builtin;
static NORETURN_PTR void (*die_routine)(const char *err, va_list params) = die_builtin;
static void (*error_routine)(const char *err, va_list params) = error_builtin;
static void (*warn_routine)(const char *err, va_list params) = warn_builtin;
static int (*die_is_recursing)(void) = die_is_recursing_builtin;

void set_die_routine(NORETURN_PTR void (*routine)(const char *err, va_list params))
{
        die_routine = routine;
}

void set_error_routine(void (*routine)(const char *err, va_list params))
{
        error_routine = routine;
}

void (*get_error_routine(void))(const char *err, va_list params)
{
        return error_routine;
}

void set_warn_routine(void (*routine)(const char *warn, va_list params))
{
        warn_routine = routine;
}

void (*get_warn_routine(void))(const char *warn, va_list params)
{
        return warn_routine;
}

void set_die_is_recursing_routine(int (*routine)(void))
{
        die_is_recursing = routine;
}

void set_error_handle(FILE *fh)
{
        error_handle = fh;
        tweaked_error_buffering = 0;
}

void NORETURN usagef(const char *err, ...)
{
        va_list params;

        va_start(params, err);
        usage_routine(err, params);
        va_end(params);
}

void NORETURN usage(const char *err)
{
        usagef("%s", err);
}

void NORETURN die(const char *err, ...)
{
        va_list params;

        if (die_is_recursing()) {
                fputs("fatal: recursion detected in die handler\n", stderr);
                exit(128);
        }

        va_start(params, err);
        die_routine(err, params);
        va_end(params);
}

static const char *fmt_with_err(char *buf, int n, const char *fmt)
{
        char str_error[256], *err;
        int i, j;

        err = strerror(errno);
        for (i = j = 0; err[i] && j < sizeof(str_error) - 1; ) {
                if ((str_error[j++] = err[i++]) != '%')
                        continue;
                if (j < sizeof(str_error) - 1) {
                        str_error[j++] = '%';
                } else {
                        /* No room to double the '%', so we overwrite it with
                         * '\0' below */
                        j--;
                        break;
                }
        }
        str_error[j] = 0;
        snprintf(buf, n, "%s: %s", fmt, str_error);
        return buf;
}

void NORETURN die_errno(const char *fmt, ...)
{
        char buf[1024];
        va_list params;

        if (die_is_recursing()) {
                fputs("fatal: recursion detected in die_errno handler\n",
                        stderr);
                exit(128);
        }

        va_start(params, fmt);
        die_routine(fmt_with_err(buf, sizeof(buf), fmt), params);
        va_end(params);
}

#undef error_errno
int error_errno(const char *fmt, ...)
{
        char buf[1024];
        va_list params;

        va_start(params, fmt);
        error_routine(fmt_with_err(buf, sizeof(buf), fmt), params);
        va_end(params);
        return -1;
}

#undef error
int error(const char *err, ...)
{
        va_list params;

        va_start(params, err);
        error_routine(err, params);
        va_end(params);
        return -1;
}

void warning_errno(const char *warn, ...)
{
        char buf[1024];
        va_list params;

        va_start(params, warn);
        warn_routine(fmt_with_err(buf, sizeof(buf), warn), params);
        va_end(params);
}

void warning(const char *warn, ...)
{
        va_list params;

        va_start(params, warn);
        warn_routine(warn, params);
        va_end(params);
}