/*
 * Copyright (C) 2011 Andrea Mazzoleni
 *
 * 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 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */

#include "portable.h"

#include "util.h"
#include "elem.h"
#include "state.h"
#include "parity.h"
#include "handle.h"

/****************************************************************************/
/* dry */

static int state_dry_process(struct snapraid_state* state, struct snapraid_parity_handle** parity, block_off_t blockstart, block_off_t blockmax)
{
	struct snapraid_handle* handle;
	unsigned diskmax;
	block_off_t i;
	unsigned j;
	void* buffer_alloc;
	unsigned char* buffer_aligned;
	int ret;
	data_off_t countsize;
	block_off_t countpos;
	block_off_t countmax;
	unsigned error;
	unsigned l;

	handle = handle_map(state, &diskmax);

	buffer_aligned = malloc_nofail_align(state->block_size, &buffer_alloc);

	error = 0;

	/* drop until now */
	state_usage_waste(state);

	countmax = blockmax - blockstart;
	countsize = 0;
	countpos = 0;
	state_progress_begin(state, blockstart, blockmax, countmax);
	for (i = blockstart; i < blockmax; ++i) {
		/* for each disk, process the block */
		for (j = 0; j < diskmax; ++j) {
			int read_size;
			struct snapraid_block* block = BLOCK_EMPTY;
			struct snapraid_disk* disk = handle[j].disk;

			if (!disk) {
				/* if no disk, nothing to do */
				continue;
			}

			block = disk_block_get(disk, i);

			if (!block_has_file(block)) {
				/* if no file, nothing to do */
				continue;
			}

			/* until now is CPU */
			state_usage_cpu(state);

			/* if the file is closed or different than the current one */
			if (handle[j].file == 0 || handle[j].file != block_file_get(block)) {
				struct snapraid_file* file = handle[j].file;
				ret = handle_close(&handle[j]);
				if (ret == -1) {
					/* LCOV_EXCL_START */
					msg_tag("error:%u:%s:%s: Close error. %s\n", i, disk->name, esc(file->sub), strerror(errno));
					msg_error("DANGER! Unexpected close error in a data disk, it isn't possible to dry.\n");
					msg_error("Stopping at block %u\n", i);
					++error;
					goto bail;
					/* LCOV_EXCL_STOP */
				}

				/* open the file only for reading */
				ret = handle_open(&handle[j], block_file_get(block), state->file_mode, msg_error);
				if (ret == -1) {
					/* LCOV_EXCL_START */
					msg_error("DANGER! Unexpected open error in a data disk, it isn't possible to dry.\n");
					msg_error("Stopping at block %u\n", i);
					++error;
					goto bail;
					/* LCOV_EXCL_STOP */
				}
			}

			/* read from the file */
			read_size = handle_read(&handle[j], block, buffer_aligned, state->block_size, msg_warning);
			if (read_size == -1) {
				msg_tag("error:%u:%s:%s: Read error at position %u\n", i, disk->name, esc(block_file_get(block)->sub), block_file_pos(block));
				++error;
				continue;
			}

			/* until now is disk */
			state_usage_disk(state, disk);

			countsize += read_size;
		}

		/* read the parity */
		for (l = 0; l < state->level; ++l) {
			if (parity[l]) {
				/* until now is CPU */
				state_usage_cpu(state);

				ret = parity_read(parity[l], i, buffer_aligned, state->block_size, msg_warning);
				if (ret == -1) {
					msg_tag("parity_error:%u:%s: Read error\n", i, lev_config_name(l));
					++error;
				}

				/* until now is parity */
				state_usage_parity(state, l);
			}
		}

		/* count the number of processed block */
		++countpos;

		/* progress */
		if (state_progress(state, i, countpos, countmax, countsize)) {
			/* LCOV_EXCL_START */
			break;
			/* LCOV_EXCL_STOP */
		}
	}

	state_progress_end(state, countpos, countmax, countsize);

	state_usage_print(state);

bail:
	/* close all the files left open */
	for (j = 0; j < diskmax; ++j) {
		struct snapraid_file* file = handle[j].file;
		struct snapraid_disk* disk = handle[j].disk;
		ret = handle_close(&handle[j]);
		if (ret == -1) {
			/* LCOV_EXCL_START */
			msg_tag("error:%u:%s:%s: Close error. %s\n", i, disk->name, esc(file->sub), strerror(errno));
			msg_error("DANGER! Unexpected close error in a data disk.\n");
			++error;
			/* continue, as we are already exiting */
			/* LCOV_EXCL_STOP */
		}
	}

	if (error) {
		msg_status("\n");
		msg_status("%8u errors\n", error);
	} else {
		msg_status("Everything OK\n");
	}

	if (error)
		msg_error("DANGER! Unexpected errors!\n");

	free(handle);
	free(buffer_alloc);

	if (error != 0)
		return -1;
	return 0;
}

void state_dry(struct snapraid_state* state, block_off_t blockstart, block_off_t blockcount)
{
	block_off_t blockmax;
	int ret;
	struct snapraid_parity_handle parity[LEV_MAX];
	/* the following initialization is to avoid clang warnings about */
	/* potential state->level change, that never happens */
	struct snapraid_parity_handle* parity_ptr[LEV_MAX] = { 0 };
	unsigned error;
	unsigned l;

	msg_progress("Drying...\n");

	blockmax = parity_allocated_size(state);

	if (blockstart > blockmax) {
		/* LCOV_EXCL_START */
		msg_error("Error in the specified starting block %u. It's bigger than the parity size %u.\n", blockstart, blockmax);
		exit(EXIT_FAILURE);
		/* LCOV_EXCL_STOP */
	}

	/* adjust the number of block to process */
	if (blockcount != 0 && blockstart + blockcount < blockmax) {
		blockmax = blockstart + blockcount;
	}

	/* open the file for reading */
	/* it may fail if the file doesn't exist, in this case we continue to dry the files */
	for (l = 0; l < state->level; ++l) {
		parity_ptr[l] = &parity[l];
		ret = parity_open(parity_ptr[l], state->parity[l].path, state->file_mode);
		if (ret == -1) {
			msg_status("No accessible %s file.\n", lev_name(l));
			/* continue anyway */
			parity_ptr[l] = 0;
		}
	}

	error = 0;

	/* skip degenerated cases of empty parity, or skipping all */
	if (blockstart < blockmax) {
		ret = state_dry_process(state, parity_ptr, blockstart, blockmax);
		if (ret == -1) {
			/* LCOV_EXCL_START */
			++error;
			/* continue, as we are already exiting */
			/* LCOV_EXCL_STOP */
		}
	}

	/* try to close only if opened */
	for (l = 0; l < state->level; ++l) {
		if (parity_ptr[l]) {
			ret = parity_close(parity_ptr[l]);
			if (ret == -1) {
				/* LCOV_EXCL_START */
				++error;
				/* continue, as we are already exiting */
				/* LCOV_EXCL_STOP */
			}
		}
	}

	/* abort if required */
	if (error != 0) {
		/* LCOV_EXCL_START */
		exit(EXIT_FAILURE);
		/* LCOV_EXCL_STOP */
	}
}