#include "pipeline.h"

#include <stdlib.h>
#include <string.h>

extern const struct ec3_pipeline_stage_type pipeline_zstd;
extern const struct ec3_pipeline_stage_type pipeline_aes256;
extern const struct ec3_pipeline_stage_type pipeline_file;

static const struct ec3_pipeline_stage_type *stage_types[] = {
	[EC3_PIPELINE_ZSTD] = &pipeline_zstd,
	[EC3_PIPELINE_AES256] = &pipeline_aes256,
	[EC3_PIPELINE_FILE] = &pipeline_file,
};
static const size_t nr_stage_types = sizeof stage_types / sizeof stage_types[0];

static enum ec3_status create_pipeline_stage(
	const struct ec3_pipeline_stage_type *type,
	size_t cluster_size,
	void *arg,
	struct ec3_pipeline_stage **out)
{
	struct ec3_pipeline_stage *stage = malloc(sizeof *stage);
	if (!stage) {
		return EC3_ERR_NO_MEMORY;
	}

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

	stage->s_type = type;
	stage->s_arg = arg;

	if (type->t_flags & EC3_PIPELINE_F_BUFFERED) {
		stage->s_buf = malloc(cluster_size);

		if (!stage) {
			free(stage);
			return EC3_ERR_NO_MEMORY;
		}

		memset(stage->s_buf, 0x0, cluster_size);
	}

	*out = stage;
	return EC3_SUCCESS;
}

extern enum ec3_status ec3_pipeline_create(
	struct ec3_pipeline_stage_args stages[],
	size_t nr_stages,
	size_t cluster_size,
	struct ec3_pipeline **out)
{
	enum ec3_status status = EC3_SUCCESS;
	struct ec3_pipeline *pipeline = malloc(sizeof *pipeline);

	if (!pipeline) {
		return EC3_ERR_NO_MEMORY;
	}

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

	for (size_t i = 0; i < nr_stages; i++) {
		struct ec3_pipeline_stage_args *args = &stages[i];

		if (args->type == EC3_PIPELINE_NONE) {
			continue;
		}

		if (args->type < 0 || args->type >= nr_stage_types) {
			return EC3_ERR_NOT_SUPPORTED;
		}

		const struct ec3_pipeline_stage_type *type
			= stage_types[stages[i].type];

		if (!type) {
			return EC3_ERR_NOT_SUPPORTED;
		}

		struct ec3_pipeline_stage *stage = NULL;
		status = create_pipeline_stage(
			type,
			cluster_size,
			args->arg,
			&stage);
		if (status != EC3_SUCCESS) {
			return status;
		}

		b_queue_push_back(&pipeline->p_stages, &stage->s_entry);
	}

	*out = pipeline;
	return status;
}

void ec3_pipeline_destroy(struct ec3_pipeline *p)
{
}

enum ec3_status ec3_pipeline_data_out(
	struct ec3_pipeline *pipeline,
	void *p,
	size_t len,
	size_t *nr_written)
{
	b_queue_entry *cur = b_queue_first(&pipeline->p_stages);
	enum ec3_status status = EC3_SUCCESS;
	void *src = p;

	size_t stage_in_size = len;
	size_t stage_out_size = 0;

	while (cur) {
		struct ec3_pipeline_stage *stage
			= b_unbox(struct ec3_pipeline_stage, cur, s_entry);

		void *dest;
		if (stage->s_type->t_flags & EC3_PIPELINE_F_BUFFERED) {
			dest = stage->s_buf;
		} else {
			dest = src;
		}

		status = stage->s_type->t_data_out(
			stage,
			src,
			stage_in_size,
			dest,
			&stage_out_size);

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

		src = dest;
		stage_in_size = stage_out_size;
		cur = b_queue_next(cur);
	}

	if (nr_written) {
		*nr_written = stage_out_size;
	}

	return EC3_SUCCESS;
}

enum ec3_status ec3_pipeline_data_in(
	struct ec3_pipeline *pipeline,
	void *p,
	size_t max,
	size_t *nr_read)
{
	return EC3_ERR_NOT_SUPPORTED;
}