/* Copyright (c) 2010-2018 Dovecot authors, see the included COPYING file */

#include "lib.h"
#include "array.h"
#include "str.h"
#include "strescape.h"
#include "ostream.h"
#include "doveadm.h"
#include "doveadm-print-private.h"
#include "client-connection.h"

#define DOVEADM_PRINT_FLUSH_TIMEOUT_SECS 60

struct doveadm_print_server_context {
	unsigned int header_idx, header_count;

	string_t *str;
};

static struct doveadm_print_server_context ctx;

static void doveadm_print_server_flush(void);

static void doveadm_print_server_init(void)
{
	ctx.str = str_new(default_pool, 256);
}

static void doveadm_print_server_deinit(void)
{
	str_free(&ctx.str);
}

static void
doveadm_print_server_header(const struct doveadm_print_header *hdr ATTR_UNUSED)
{
	/* no need to transfer these. the client should already know what
	   it's getting */
	ctx.header_count++;
}

static void doveadm_print_server_print(const char *value)
{
	str_append_tabescaped(ctx.str, value);
	str_append_c(ctx.str, '\t');

	if (++ctx.header_idx == ctx.header_count) {
		ctx.header_idx = 0;
		doveadm_print_server_flush();
	}
}

static void
doveadm_print_server_print_stream(const unsigned char *value, size_t size)
{
	if (size == 0) {
		doveadm_print_server_print("");
		return;
	}
	str_append_tabescaped_n(ctx.str, value, size);

	if (str_len(ctx.str) >= IO_BLOCK_SIZE)
		doveadm_print_server_flush();
}

static int flush_callback(struct doveadm_print_server_context *ctx ATTR_UNUSED)
{

	int ret;
	/* Keep flushing until everything is sent */
	if ((ret = o_stream_flush(doveadm_print_ostream)) != 0)
		io_loop_stop(current_ioloop);
	return ret;
}

static void handle_flush_timeout(struct doveadm_print_server_context *ctx ATTR_UNUSED)
{
	io_loop_stop(current_ioloop);
	o_stream_close(doveadm_print_ostream);
	i_error("write(%s) failed: Timed out after %u seconds",
		o_stream_get_name(doveadm_print_ostream),
		DOVEADM_PRINT_FLUSH_TIMEOUT_SECS);
}

static void doveadm_print_server_flush(void)
{
	o_stream_nsend(doveadm_print_ostream,
		       str_data(ctx.str), str_len(ctx.str));
	str_truncate(ctx.str, 0);
	o_stream_uncork(doveadm_print_ostream);

	if (o_stream_get_buffer_used_size(doveadm_print_ostream) < IO_BLOCK_SIZE ||
	    doveadm_print_ostream->stream_errno != 0)
		return;
	/* Wait until buffer is flushed to avoid it growing too large */
	struct ioloop *prev_loop = current_ioloop;
	struct ioloop *loop = io_loop_create();
	/* Ensure we don't get stuck here forever */
	struct timeout *to =
		timeout_add(DOVEADM_PRINT_FLUSH_TIMEOUT_SECS*1000, handle_flush_timeout, &ctx);
	o_stream_switch_ioloop_to(doveadm_print_ostream, loop);
	o_stream_set_flush_callback(doveadm_print_ostream, flush_callback, &ctx);
	io_loop_run(loop);
	timeout_remove(&to);
	o_stream_unset_flush_callback(doveadm_print_ostream);
	o_stream_switch_ioloop_to(doveadm_print_ostream, prev_loop);
	io_loop_destroy(&loop);
}

struct doveadm_print_vfuncs doveadm_print_server_vfuncs = {
	DOVEADM_PRINT_TYPE_SERVER,

	doveadm_print_server_init,
	doveadm_print_server_deinit,
	doveadm_print_server_header,
	doveadm_print_server_print,
	doveadm_print_server_print_stream,
	doveadm_print_server_flush
};