#include "tag.h"

#include "image.h"
#include "pipeline.h"
#include "status.h"

#include <blue/io/file.h>
#include <stdlib.h>
#include <string.h>

static enum ec3_status init_seq_write_temp_files(struct ec3_tag_ioctx *tag)
{
	b_status status = b_file_open_temp(
		B_FILE_READ_WRITE | B_FILE_BINARY,
		&tag->io_f_data);

	if (!B_OK(status)) {
		return ec3_status_from_b_status(status, EC3_ERR_IO_FAILURE);
	}

	status = b_file_open_temp(
		B_FILE_READ_WRITE | B_FILE_BINARY,
		&tag->io_f_cluster_table);

	if (!B_OK(status)) {
		return ec3_status_from_b_status(status, EC3_ERR_IO_FAILURE);
	}

	cluster_table_init(&tag->io_cluster_table, tag->io_f_cluster_table, 0);
	cluster_table_init_empty_table(&tag->io_cluster_table);

	return EC3_SUCCESS;
}

enum ec3_status ec3_tag_ioctx_create(
	struct ec3_tag_ioctx **out,
	size_t cluster_size,
	enum ec3_tag_ioctx_mode mode)
{
	if ((mode & EC3_TAG_IO_READ) && (mode & EC3_TAG_IO_SEQUENTIAL)) {
		return EC3_ERR_INVALID_VALUE;
	}

	struct ec3_tag_ioctx *ioctx = malloc(sizeof *ioctx);
	if (!ioctx) {
		return EC3_ERR_NO_MEMORY;
	}

	memset(ioctx, 0x0, sizeof *ioctx);

	ioctx->io_mode = mode;

	ioctx->io_cluster_buf = malloc(cluster_size);
	if (!ioctx->io_cluster_buf) {
		free(ioctx);
		return EC3_ERR_NO_MEMORY;
	}

	enum ec3_status status = EC3_SUCCESS;

	if (mode & EC3_TAG_IO_SEQUENTIAL) {
		status = init_seq_write_temp_files(ioctx);
	} else {
		status = cluster_cache_init(
			&ioctx->io_cache,
			(mode & EC3_TAG_IO_WRITE) == EC3_TAG_IO_WRITE,
			cluster_size);
	}

	if (status != EC3_SUCCESS) {
		ec3_tag_ioctx_close(ioctx);
		return status;
	}

	*out = ioctx;
	return EC3_SUCCESS;
}

enum ec3_status ec3_tag_ioctx_close(struct ec3_tag_ioctx *tag)
{
	enum ec3_tag_ioctx_mode mode = tag->io_mode;
	tag->io_mode |= EC3_TAG_IO_CLOSED;

	if (tag->io_f_image) {
		b_file_release(tag->io_f_image);
		tag->io_f_image = NULL;
	}

	if (tag->io_cluster_buf) {
		free(tag->io_cluster_buf);
		tag->io_cluster_buf = NULL;
	}

	if (mode & EC3_TAG_IO_WRITE) {
		/* leave the rest of the data for the image ioctx to use */
		return EC3_SUCCESS;
	}

	if (tag->io_pipeline) {
		ec3_pipeline_destroy(tag->io_pipeline);
		tag->io_pipeline = NULL;
	}

	if (tag->io_f_data) {
		b_file_release(tag->io_f_data);
		tag->io_f_data = NULL;
	}

	if (tag->io_f_cluster_table) {
		b_file_release(tag->io_f_cluster_table);
		tag->io_f_cluster_table = NULL;
	}

	cluster_cache_finish(&tag->io_cache);
	cluster_table_finish(&tag->io_cluster_table);
	b_btree_delete(&tag->io_parent->io_opened_tags, &tag->io_node);
	free(tag);

	return EC3_SUCCESS;
}

enum ec3_status ec3_tag_ioctx_read_cluster(
	struct ec3_tag_ioctx *tag,
	size_t cluster_id,
	void *buf,
	size_t *nr_read)
{
	if (!(tag->io_mode & EC3_TAG_IO_READ)) {
		return EC3_ERR_NOT_SUPPORTED;
	}

	if (tag->io_mode & EC3_TAG_IO_SEQUENTIAL) {
		return EC3_ERR_NOT_SUPPORTED;
	}

	enum ec3_status status
		= cluster_cache_get(&tag->io_cache, cluster_id, buf, nr_read);
	if (status == EC3_SUCCESS) {
		return EC3_SUCCESS;
	}

	size_t physical_cluster_id = 0;
	status = ec3_image_ioctx_cluster_logical_to_physical(
		tag->io_parent,
		tag->io_tag_info,
		cluster_id,
		&physical_cluster_id);

	if (status != EC3_SUCCESS) {
		return status;
	}

	/* the cluster isn't in the cache, and needs to be read from the main
	 * image */
	struct cluster cluster_info;
	status = cluster_table_get(
		&tag->io_cluster_table,
		physical_cluster_id,
		&cluster_info);

	if (status != EC3_SUCCESS) {
		return status;
	}

	if (cluster_info.c_len > tag->io_parent->io_header.img_cluster_size) {
		return EC3_ERR_BAD_FORMAT;
	}

	size_t offset = tag->io_cluster_data_offset + cluster_info.c_base;
	size_t r;
	enum b_status status2 = b_file_read(
		tag->io_f_image,
		offset,
		cluster_info.c_len,
		tag->io_cluster_buf,
		&r);

	if (!B_OK(status2)) {
		return ec3_status_from_b_status(status2, EC3_ERR_IO_FAILURE);
	}

	status = ec3_pipeline_decode_cluster(
		tag->io_pipeline,
		tag->io_cluster_buf,
		cluster_info.c_len,
		buf,
		tag->io_parent->io_header.img_cluster_size,
		nr_read);

	if (status != EC3_SUCCESS) {
		return status;
	}

	cluster_cache_put(&tag->io_cache, cluster_id, buf, *nr_read);
	return EC3_SUCCESS;
}

enum ec3_status ec3_tag_ioctx_write_cluster(
	struct ec3_tag_ioctx *tag,
	size_t cluster_id,
	void *buf,
	size_t len,
	size_t *nr_written)
{
	if (!(tag->io_mode & EC3_TAG_IO_WRITE)) {
		return EC3_ERR_NOT_SUPPORTED;
	}

	enum ec3_status status = EC3_SUCCESS;

	if (!(tag->io_mode & EC3_TAG_IO_SEQUENTIAL)) {
		status = cluster_cache_put(
			tag->io_cluster_buf,
			cluster_id,
			buf,
			len);

		if (status != EC3_SUCCESS) {
			return status;
		}

		*nr_written = len;
		return EC3_SUCCESS;
	}

	if (cluster_id != tag->io_seq_cluster_id) {
		/* can only write to each cluster once, sequentially, in this
		 * mode */
		return EC3_ERR_NOT_SUPPORTED;
	}

	size_t offset = 0;
	b_file_size(tag->io_f_data, &offset);

	size_t encoded_len = 0;
	ec3_pipeline_encode_cluster(
		tag->io_pipeline,
		buf,
		len,
		tag->io_cluster_buf,
		tag->io_parent->io_header.img_cluster_size,
		&encoded_len);

	b_status status2 = b_file_write(
		tag->io_f_data,
		offset,
		encoded_len,
		tag->io_cluster_buf,
		nr_written);

	if (!B_OK(status2)) {
		return ec3_status_from_b_status(status2, EC3_ERR_IO_FAILURE);
	}

	struct cluster cluster = {0};
	cluster.c_id = cluster_id;
	cluster.c_base = offset;
	cluster.c_len = *nr_written;

	cluster_table_put(&tag->io_cluster_table, &cluster);

	tag->io_seq_cluster_id++;

	return EC3_SUCCESS;
}

enum ec3_status ec3_tag_ioctx_get_nr_clusters(
	struct ec3_tag_ioctx *tag,
	size_t *out_nr_clusters)
{
	size_t nr_clusters = 0;

	const struct ec3_extent_info *extents
		= ec3_image_ioctx_get_extent_info(tag->io_parent);
	size_t nr_extents = tag->io_parent->io_header.img_nr_extents;

	for (size_t i = 0; i < nr_extents; i++) {
		const struct ec3_extent_info *x = &extents[i];
		if (x->ex_owner != tag->io_tag_info->tag_ident) {
			continue;
		}

		if (x->ex_logical_cluster + x->ex_count > nr_clusters) {
			nr_clusters = x->ex_logical_cluster + x->ex_count;
		}
	}

	size_t highest_cached_cluster;

	enum ec3_status status = cluster_cache_get_highest_cluster_id(
		&tag->io_cache,
		&highest_cached_cluster);

	if (status == EC3_SUCCESS && highest_cached_cluster >= nr_clusters) {
		nr_clusters = highest_cached_cluster + 1;
	}

	*out_nr_clusters = nr_clusters;
	return EC3_SUCCESS;
}