/* -*- Mode: C; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4; coding: utf-8 -*-
 *
 *   moocmd.c
 *
 *   Copyright (C) 2004-2006 by Yevgen Muntyan <muntyan@math.tamu.edu>
 *
 *   This program is free software; you can redistribute it and/or modify
 *   it under the terms of the GNU General Public License as published by
 *   the Free Software Foundation; either version 2 of the License, or
 *   (at your option) any later version.
 *
 *   See COPYING file that comes with this distribution.
 */

#include "mooutils/moocmd.h"
#include "mooutils/moomarshals.h"

#ifndef __WIN32__
#include <sys/wait.h>
#include <unistd.h>
#include <signal.h>
#else
#define WIN32_LEAN_AND_MEAN
#include <windows.h>
#endif


struct _MooCmdPrivate {
    GSpawnFlags flags;
    MooCmdFlags cmd_flags;
    gboolean running;
    int exit_status;
    GPid pid;
    int stdout;
    int stderr;
    GIOChannel *stdout_io;
    GIOChannel *stderr_io;
    guint child_watch;
    guint stdout_watch;
    guint stderr_watch;
};

static void     moo_cmd_finalize        (GObject    *object);
static void     moo_cmd_dispose         (GObject    *object);

static void     moo_cmd_check_stop      (MooCmd     *cmd);
static void     moo_cmd_cleanup         (MooCmd     *cmd);

static gboolean moo_cmd_abort_real      (MooCmd     *cmd);
static gboolean moo_cmd_stdout_text     (MooCmd     *cmd,
                                         const char *text);
static gboolean moo_cmd_stderr_text     (MooCmd     *cmd,
                                         const char *text);

static gboolean moo_cmd_run_command     (MooCmd     *cmd,
                                         const char *working_dir,
                                         char      **argv,
                                         char      **envp,
                                         GSpawnFlags flags,
                                         MooCmdFlags cmd_flags,
                                         GSpawnChildSetupFunc child_setup,
                                         gpointer    user_data,
                                         GError    **error);



enum {
    ABORT,
    CMD_EXIT,
    STDOUT_TEXT,
    STDERR_TEXT,
    LAST_SIGNAL
};

static guint signals[LAST_SIGNAL];


enum {
    PROP_0,
};


/* MOO_TYPE_CMD */
G_DEFINE_TYPE (MooCmd, moo_cmd, G_TYPE_OBJECT)


static void
moo_cmd_class_init (MooCmdClass *klass)
{
    GObjectClass *gobject_class = G_OBJECT_CLASS (klass);

    gobject_class->finalize = moo_cmd_finalize;
    gobject_class->dispose = moo_cmd_dispose;

    klass->abort = moo_cmd_abort_real;
    klass->cmd_exit = NULL;
    klass->stdout_text = moo_cmd_stdout_text;
    klass->stderr_text = moo_cmd_stderr_text;

    signals[ABORT] =
            g_signal_new ("abort",
                          G_OBJECT_CLASS_TYPE (klass),
                          G_SIGNAL_RUN_LAST | G_SIGNAL_ACTION,
                          G_STRUCT_OFFSET (MooCmdClass, abort),
                          g_signal_accumulator_true_handled, NULL,
                          _moo_marshal_BOOL__VOID,
                          G_TYPE_BOOLEAN, 0);

    signals[CMD_EXIT] =
            g_signal_new ("cmd-exit",
                          G_OBJECT_CLASS_TYPE (klass),
                          G_SIGNAL_RUN_LAST,
                          G_STRUCT_OFFSET (MooCmdClass, cmd_exit),
                          g_signal_accumulator_true_handled, NULL,
                          _moo_marshal_BOOL__INT,
                          G_TYPE_BOOLEAN, 1,
                          G_TYPE_INT);

    signals[STDOUT_TEXT] =
            g_signal_new ("stdout-text",
                          G_OBJECT_CLASS_TYPE (klass),
                          G_SIGNAL_RUN_LAST,
                          G_STRUCT_OFFSET (MooCmdClass, stdout_text),
                          g_signal_accumulator_true_handled, NULL,
                          _moo_marshal_BOOL__STRING,
                          G_TYPE_BOOLEAN, 1,
                          G_TYPE_STRING);

    signals[STDERR_TEXT] =
            g_signal_new ("stderr-text",
                          G_OBJECT_CLASS_TYPE (klass),
                          G_SIGNAL_RUN_LAST,
                          G_STRUCT_OFFSET (MooCmdClass, stderr_text),
                          g_signal_accumulator_true_handled, NULL,
                          _moo_marshal_BOOL__STRING,
                          G_TYPE_BOOLEAN, 1,
                          G_TYPE_STRING);
}


static void
moo_cmd_init (MooCmd *cmd)
{
    cmd->priv = g_new0 (MooCmdPrivate, 1);
    cmd->out_buffer = g_string_new (NULL);
    cmd->err_buffer = g_string_new (NULL);
}


static void
moo_cmd_finalize (GObject *object)
{
    MooCmd *cmd = MOO_CMD (object);

    g_string_free (cmd->out_buffer, TRUE);
    g_string_free (cmd->err_buffer, TRUE);

    g_free (cmd->priv);

    G_OBJECT_CLASS (moo_cmd_parent_class)->finalize (object);
}


static void
moo_cmd_dispose (GObject *object)
{
    MooCmd *cmd = MOO_CMD (object);

    if (cmd->priv->pid)
        moo_cmd_abort (cmd);
    moo_cmd_cleanup (cmd);

    G_OBJECT_CLASS (moo_cmd_parent_class)->dispose (object);
}


MooCmd*
moo_cmd_new_full (const char *working_dir,
                  char      **argv,
                  char      **envp,
                  GSpawnFlags flags,
                  MooCmdFlags cmd_flags,
                  GSpawnChildSetupFunc child_setup,
                  gpointer    user_data,
                  GError    **error)
{
    MooCmd *cmd;
    gboolean result;

    g_return_val_if_fail (argv && *argv, NULL);

    cmd = g_object_new (MOO_TYPE_CMD, NULL);

    result = moo_cmd_run_command (cmd, working_dir, argv, envp,
                                  flags, cmd_flags, child_setup,
                                  user_data, error);

    if (result)
    {
        return cmd;
    }
    else
    {
        g_object_unref (cmd);
        return NULL;
    }
}


static void
command_exit (GPid    pid,
              gint    status,
              MooCmd *cmd)
{
    g_return_if_fail (pid == cmd->priv->pid);

    cmd->priv->child_watch = 0;
    cmd->priv->exit_status = status;

    g_spawn_close_pid (cmd->priv->pid);
    cmd->priv->pid = 0;

    moo_cmd_check_stop (cmd);
}


static void
process_text (MooCmd      *cmd,
              const char  *text,
              gboolean     stderr)
{
    gboolean dummy = FALSE;
    const char *real_text = text;
    char *freeme = NULL;

    if (cmd->priv->cmd_flags & MOO_CMD_UTF8_OUTPUT)
    {
        const char *charset;

        real_text = NULL;

        if (g_get_charset (&charset))
        {
            const char *end;

            if (!g_utf8_validate (text, -1, &end))
            {
                g_warning ("%s: invalid unicode:\n%s", G_STRLOC, text);

                if (end > text)
                {
                    freeme = g_strndup (text, end - text);
                    real_text = freeme;
                }
            }
            else
            {
                real_text = text;
            }
        }
        else
        {
            GError *error = NULL;

            freeme = g_convert_with_fallback (text, -1, "UTF8", charset,
                                              NULL, NULL, NULL, &error);

            if (!freeme)
            {
                g_warning ("%s: could not convert text to UTF8:\n%s",
                           G_STRLOC, text);
                g_warning ("%s: %s", G_STRLOC, error->message);
            }

            real_text = freeme;
        }
    }

    if (real_text)
    {
        if (stderr)
            g_signal_emit (cmd, signals[STDERR_TEXT], 0, real_text, &dummy);
        else
            g_signal_emit (cmd, signals[STDOUT_TEXT], 0, real_text, &dummy);
    }

    g_free (freeme);
}


static gboolean
command_out_or_err (MooCmd         *cmd,
                    GIOChannel     *channel,
                    GIOCondition    condition,
                    gboolean        stdout)
{
    char *line;
    gsize line_end;
    GError *error = NULL;
    GIOStatus status;

    status = g_io_channel_read_line (channel, &line, NULL, &line_end, &error);

    if (line)
    {
        line[line_end] = 0;
        process_text (cmd, line, !stdout);
        g_free (line);
    }

    if (error)
    {
        g_warning ("%s: %s", G_STRLOC, error->message);
        g_error_free (error);
        return FALSE;
    }

    if (condition & (G_IO_ERR | G_IO_HUP))
        return FALSE;

    if (status == G_IO_STATUS_EOF)
        return FALSE;

    return TRUE;
}


static gboolean
command_out (GIOChannel     *channel,
             GIOCondition    condition,
             MooCmd         *cmd)
{
    return command_out_or_err (cmd, channel, condition, TRUE);
}


static gboolean
command_err (GIOChannel     *channel,
             GIOCondition    condition,
             MooCmd         *cmd)
{
    return command_out_or_err (cmd, channel, condition, FALSE);
}


static char **
splitlines (const char *string)
{
    GPtrArray *array;
    const char *line, *p;

    if (!string || !string[0])
        return NULL;

    array = g_ptr_array_new ();

    p = line = string;

    while (*p)
    {
        switch (*p)
        {
            case '\r':
                g_ptr_array_add (array, g_strndup (line, p - line));
                if (*++p == '\n')
                    ++p;
                line = p;
                break;

            case '\n':
                g_ptr_array_add (array, g_strndup (line, p - line));
                line = ++p;
                break;

            default:
                ++p;
        }
    }

    g_ptr_array_add (array, NULL);
    return (char**) g_ptr_array_free (array, FALSE);
}


static void
try_channel_leftover (MooCmd      *cmd,
                      GIOChannel  *channel,
                      gboolean     stdout)
{
    char *text;

    g_io_channel_read_to_end (channel, &text, NULL, NULL);

    if (text)
    {
        char **lines, **p;

        lines = splitlines (text);

        if (lines)
        {
            for (p = lines; *p != NULL; p++)
                if (**p)
                    process_text (cmd, *p, !stdout);
        }

        g_strfreev (lines);
        g_free (text);
    }
}


static void
stdout_watch_removed (MooCmd *cmd)
{
    if (cmd->priv->stdout_io)
    {
        try_channel_leftover (cmd, cmd->priv->stdout_io, TRUE);
        g_io_channel_unref (cmd->priv->stdout_io);
    }

    cmd->priv->stdout_io = NULL;
    cmd->priv->stdout_watch = 0;
    moo_cmd_check_stop (cmd);
}


static void
stderr_watch_removed (MooCmd *cmd)
{
    if (cmd->priv->stderr_io)
    {
        try_channel_leftover (cmd, cmd->priv->stderr_io, TRUE);
        g_io_channel_unref (cmd->priv->stderr_io);
    }

    cmd->priv->stderr_io = NULL;
    cmd->priv->stderr_watch = 0;
    moo_cmd_check_stop (cmd);
}


#ifndef __WIN32__
static void
real_child_setup (gpointer user_data)
{
    struct {
        GSpawnChildSetupFunc child_setup;
        gpointer user_data;
    } *data = user_data;

    setpgid (0, 0);

    if (data->child_setup)
        data->child_setup (data->user_data);
}
#endif


static gboolean
moo_cmd_run_command (MooCmd     *cmd,
                     const char *working_dir,
                     char      **argv,
                     char      **envp,
                     GSpawnFlags flags,
                     MooCmdFlags cmd_flags,
                     G_GNUC_UNUSED GSpawnChildSetupFunc child_setup,
                     G_GNUC_UNUSED gpointer    user_data,
                     GError    **error)
{
    gboolean result;
    int *outp, *errp;

#ifndef __WIN32__
    struct {
        GSpawnChildSetupFunc child_setup;
        gpointer user_data;
    } data = {child_setup, user_data};
#endif

    g_return_val_if_fail (MOO_IS_CMD (cmd), FALSE);
    g_return_val_if_fail (argv && argv[0], FALSE);

    g_return_val_if_fail (!cmd->priv->running, FALSE);

    if ((flags & G_SPAWN_STDOUT_TO_DEV_NULL) || (cmd_flags & MOO_CMD_STDOUT_TO_PARENT))
        outp = NULL;
    else
        outp = &cmd->priv->stdout;

    if ((flags & G_SPAWN_STDERR_TO_DEV_NULL) || (cmd_flags & MOO_CMD_STDERR_TO_PARENT))
        errp = NULL;
    else
        errp = &cmd->priv->stderr;

    result = g_spawn_async_with_pipes (working_dir,
                                       argv, envp,
                                       flags | G_SPAWN_DO_NOT_REAP_CHILD,
#ifndef __WIN32__
                                       real_child_setup, &data,
#else
                                       NULL, NULL,
#endif
                                       &cmd->priv->pid,
                                       NULL, outp, errp, error);

    if (!result)
        return FALSE;

    cmd->priv->running = TRUE;
    cmd->priv->flags = flags;
    cmd->priv->cmd_flags = cmd_flags;

    cmd->priv->child_watch =
            g_child_watch_add (cmd->priv->pid,
                               (GChildWatchFunc) command_exit,
                               cmd);

    if (outp)
    {
        cmd->priv->stdout_io = g_io_channel_unix_new (cmd->priv->stdout);
        g_io_channel_set_encoding (cmd->priv->stdout_io, NULL, NULL);
        g_io_channel_set_buffered (cmd->priv->stdout_io, TRUE);
        g_io_channel_set_flags (cmd->priv->stdout_io, G_IO_FLAG_NONBLOCK, NULL);
        g_io_channel_set_close_on_unref (cmd->priv->stdout_io, TRUE);
        cmd->priv->stdout_watch =
                g_io_add_watch_full (cmd->priv->stdout_io,
                                     G_PRIORITY_DEFAULT_IDLE,
                                     G_IO_IN | G_IO_PRI | G_IO_ERR | G_IO_HUP,
                                     (GIOFunc) command_out, cmd,
                                     (GDestroyNotify) stdout_watch_removed);
    }

    if (errp)
    {
        cmd->priv->stderr_io = g_io_channel_unix_new (cmd->priv->stderr);
        g_io_channel_set_encoding (cmd->priv->stderr_io, NULL, NULL);
        g_io_channel_set_buffered (cmd->priv->stderr_io, TRUE);
        g_io_channel_set_flags (cmd->priv->stderr_io, G_IO_FLAG_NONBLOCK, NULL);
        g_io_channel_set_close_on_unref (cmd->priv->stderr_io, TRUE);
        cmd->priv->stderr_watch =
                g_io_add_watch_full (cmd->priv->stderr_io,
                                     G_PRIORITY_DEFAULT_IDLE,
                                     G_IO_IN | G_IO_PRI | G_IO_ERR | G_IO_HUP,
                                     (GIOFunc) command_err, cmd,
                                     (GDestroyNotify) stderr_watch_removed);
    }

    return TRUE;
}


static void
moo_cmd_check_stop (MooCmd *cmd)
{
    gboolean result;

    if (!cmd->priv->running)
        return;

    if (!cmd->priv->child_watch && !cmd->priv->stdout_watch && !cmd->priv->stderr_watch)
    {
        g_object_ref (cmd);
        g_signal_emit (cmd, signals[CMD_EXIT], 0, cmd->priv->exit_status, &result);
        moo_cmd_cleanup (cmd);
        g_object_unref (cmd);
    }
}


static void
moo_cmd_cleanup (MooCmd *cmd)
{
    if (!cmd->priv->running)
        return;

    cmd->priv->running = FALSE;

    if (cmd->priv->child_watch)
        g_source_remove (cmd->priv->child_watch);
    if (cmd->priv->stdout_watch)
        g_source_remove (cmd->priv->stdout_watch);
    if (cmd->priv->stderr_watch)
        g_source_remove (cmd->priv->stderr_watch);

    if (cmd->priv->stdout_io)
        g_io_channel_unref (cmd->priv->stdout_io);
    if (cmd->priv->stderr_io)
        g_io_channel_unref (cmd->priv->stderr_io);

    if (cmd->priv->pid)
    {
#ifndef __WIN32__
        kill (-cmd->priv->pid, SIGHUP);
#else
        TerminateProcess (cmd->priv->pid, 1);
#endif
        g_spawn_close_pid (cmd->priv->pid);
        cmd->priv->pid = 0;
    }

    cmd->priv->pid = 0;
    cmd->priv->stdout = -1;
    cmd->priv->stderr = -1;
    cmd->priv->child_watch = 0;
    cmd->priv->stdout_watch = 0;
    cmd->priv->stderr_watch = 0;
    cmd->priv->stdout_io = NULL;
    cmd->priv->stderr_io = NULL;
}


static gboolean
moo_cmd_abort_real (MooCmd *cmd)
{
    if (!cmd->priv->running)
        return TRUE;

    g_return_val_if_fail (cmd->priv->pid != 0, TRUE);

#ifndef __WIN32__
    kill (-cmd->priv->pid, SIGHUP);
#else
    TerminateProcess (cmd->priv->pid, 1);
#endif

    if (cmd->priv->stdout_watch)
    {
        g_source_remove (cmd->priv->stdout_watch);
        cmd->priv->stdout_watch = 0;
    }

    if (cmd->priv->stderr_watch > 0)
    {
        g_source_remove (cmd->priv->stderr_watch);
        cmd->priv->stderr_watch = 0;
    }

    return TRUE;
}


void
moo_cmd_abort (MooCmd *cmd)
{
    gboolean handled;
    g_return_if_fail (MOO_IS_CMD (cmd));
    g_signal_emit (cmd, signals[ABORT], 0, &handled);
}


static gboolean
moo_cmd_stdout_text (MooCmd     *cmd,
                     const char *text)
{
    if (cmd->priv->cmd_flags & MOO_CMD_COLLECT_STDOUT)
        g_string_append (cmd->out_buffer, text);
    return FALSE;
}


static gboolean
moo_cmd_stderr_text (MooCmd     *cmd,
                     const char *text)
{
    if (cmd->priv->cmd_flags & MOO_CMD_COLLECT_STDERR)
        g_string_append (cmd->err_buffer, text);
    return FALSE;
}