#include <assert.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <time.h>
#include <math.h>

#include "harvensine_compute.h"
#include "timer.c"
#include "json_parser.c"
#include "harvensine_formula.c"

struct point_pair {
	f64 x0;
	f64 y0;
	f64 x1;
	f64 y1;
};

struct point_pairs {
	struct point_pair *pairs;
	size_t count;
};

void print_usage(char *program)
{
	printf("Usage: %s <json-file> [reference-bin-file]\n", program);
}

size_t get_file_size(FILE *f)
{
	fseek(f, 0, SEEK_END);
	size_t size = ftell(f);
	fseek(f, 0, SEEK_SET);
	return size;
}

u64 get_current_time_us()
{
	struct timespec time;
	clock_gettime(CLOCK_MONOTONIC_RAW, &time);
	return time.tv_sec * 1000000 + time.tv_nsec / 1000;
}

static struct point_pairs *convert_to_struct(struct json_value *json)
{
	assert(json->type == JSON_TYPE_OBJECT);
	assert(json->object->count == 1);
	assert(!strncmp(json->object->keys[0]->str, "pairs", sizeof("pairs")-1));
	assert(json->object->values[0]->type == JSON_TYPE_ARRAY);
	struct json_array *pairs_array = json->object->values[0]->array;

	struct point_pairs *result = malloc(sizeof(struct point_pairs));
	result->pairs = malloc(pairs_array->count * sizeof(struct point_pair));
	result->count = pairs_array->count;

	for (int i = 0; i < result->count; i++)
	{
		assert(pairs_array->values[i]->type == JSON_TYPE_OBJECT);
		assert(pairs_array->values[i]->object->count == 4);

		struct json_object *json_pair = pairs_array->values[i]->object;
		struct json_value *x0 = get_json_object_value(json_pair, "x0", sizeof("x0")-1);
		assert(x0 != NULL && x0->type == JSON_TYPE_NUMBER);
		struct json_value *y0 = get_json_object_value(json_pair, "y0", sizeof("y0")-1);
		assert(y0 != NULL && y0->type == JSON_TYPE_NUMBER);
		struct json_value *x1 = get_json_object_value(json_pair, "x1", sizeof("x1")-1);
		assert(x1 != NULL && x1->type == JSON_TYPE_NUMBER);
		struct json_value *y1 = get_json_object_value(json_pair, "y1", sizeof("y1")-1);
		assert(y1 != NULL && y1->type == JSON_TYPE_NUMBER);

		struct point_pair *pair = &result->pairs[i];
		pair->x0 = x0->number;
		pair->y0 = y0->number;
		pair->x1 = x1->number;
		pair->y1 = y1->number;

	}

	return result;
}

static void free_point_pairs(struct point_pairs *pairs)
{
	if (pairs == NULL)  return;
	free(pairs->pairs);
	free(pairs);
}

int main(int argc, char **argv)
{
	struct timer total_timer = START_TIMER("Total time");

	if (argc <= 1) {
		print_usage(argv[0]);
		return -1;
	}

	char *json_filename = argv[1];

	FILE *f = fopen(json_filename, "r");
	if (f == NULL) {
		printf("Failed to open: %s\n", json_filename);
		return -1;
	}

	struct timer read_files_timer = START_TIMER("Read files");
	size_t json_size = get_file_size(f);
	char json_data[json_size];
	size_t bytes_read = fread(json_data, 1, json_size, f);
	if (bytes_read != json_size) {
		printf("Failed to read all contents of file\n");
		return -1;
	}
	fclose(f);

	f64 *reference_harvensines = NULL;
	size_t reference_harvensines_count = 0;
	f64 reference_harvensine_sum = 0;
	if (argc >= 3)
	{
		char *answers_filename = argv[2];
		FILE *f = fopen(answers_filename, "r");
		if (f == NULL) {
			printf("Failed to open: %s\n", json_filename);
			return -1;
		}
		size_t file_size = get_file_size(f);
		assert(file_size % sizeof(f64) == 0);
		reference_harvensines_count = file_size / sizeof(f64) - 1;
		reference_harvensines = malloc(reference_harvensines_count * sizeof(f64));
		for (int i = 0; i < reference_harvensines_count; i++) {
			fread(&reference_harvensines[i], sizeof(f64), 1, f);
		}
		fread(&reference_harvensine_sum, sizeof(f64), 1, f);

		fclose(f);
	}
	END_TIMER(read_files_timer);

	// Step 1. Read json file

	struct timer json_parse_timer = START_TIMER("Parse JSON");
	struct json_value *parsed = NULL;
	{
		parsed = malloc(sizeof(struct json_value));
		int bytes_parsed = parse_json_value(parsed, json_data, json_size);
		assert(bytes_parsed >= 0);
	}
	END_TIMER(json_parse_timer);

	u32 row_count = parsed->object->values[0]->array->count;
	if (reference_harvensines_count > 0) {
		assert(row_count == reference_harvensines_count);
	}

	// Step 2. Convert json object to struct

	struct timer struct_convert_timer = START_TIMER("Conver to struct");
	struct point_pairs *pairs = convert_to_struct(parsed);
	END_TIMER(struct_convert_timer);

	// Step 3. Calculate harvensine distances

	struct timer harvensines_timer = START_TIMER("Compute harvensines");
	f64 *harvensines = malloc(pairs->count*sizeof(f64));
	for (int i = 0; i < pairs->count; i++) {
		struct point_pair *p = &pairs->pairs[i];
		harvensines[i] = get_harvensine_distance(p->x0, p->y0, p->x1, p->y1, EARTH_RADIUS);
	}
	END_TIMER(harvensines_timer);

	struct timer sum_harvensines_timer = START_TIMER("Sum harvensines");
	f64 harvensine_sum = 0;
	for (int i = 0; i < pairs->count; i++) {
		harvensine_sum += harvensines[i];
	}
	END_TIMER(sum_harvensines_timer);


	struct timer freeing_timer = START_TIMER("Free memory");
	free(reference_harvensines);
	free(harvensines);
	free_json_value(parsed);
	free_point_pairs(pairs);
	END_TIMER(freeing_timer);

	END_TIMER(total_timer);

	// Output results

	printf("Row count: %d\n", row_count);
	printf("Sum of all harvensines: %f\n", harvensine_sum);

	if (reference_harvensines_count > 0) {
		printf("Diff of reference harvensine sum: %.16f\n", harvensine_sum - reference_harvensine_sum);
	}

	u64 cpu_hz = get_cpu_timer_hz(100);
	u64 total_time = TIMER_DURATION(total_timer);

	printf("\nTotal time taken: %.3fms\n", (float)total_time*1000/cpu_hz);
	struct timer timers[] = {
		read_files_timer,
		json_parse_timer,
		struct_convert_timer,
		harvensines_timer,
		sum_harvensines_timer,
		freeing_timer
	};
	for (size_t i = 0; i < ARRAY_LEN(timers); i++) {
		u64 duration = TIMER_DURATION(timers[i]);
		printf("\t%20s - %9lu (%.03f%%)\n", timers[i].name, duration, (float)duration*100/total_time);
	}
	u64 other_duration = total_time - sum_timer(timers, ARRAY_LEN(timers));
	printf("\t%20s - %9lu (%.03f%%)\n", "Other", other_duration, (float)other_duration*100/total_time);

	return 0;
}