//
// Created by nicol on 2018-03-18.
//

#ifndef ESC_ESC_H
#define ESC_ESC_H

#include <stdint.h>

// bool
typedef int bool_t;
#define BOOL_TRUE 1
#define BOOL_FALSE 0

// array
typedef struct st_array array_t;
typedef void (*array_deallocator)(void*);
array_t* array_create(size_t n, ...);
void array_destroy(array_t* array, array_deallocator destroyer);

// uuid
#if defined(_WIN32) && defined(UUID_DEFINED)
#undef uuid_t
#endif
typedef struct st_uuid uuid_t;
uuid_t* uuid_create();
void uuid_destroy(uuid_t*);

// buffer
typedef struct st_buffer buffer_t;
void buffer_destroy(buffer_t*);
buffer_t* buffer_from_string(const char* str);
size_t buffer_size(buffer_t* b);

// error
#define ERROR_MSG_SIZE 1024
typedef struct st_error {
    const char* file;
    int line;
    int code;
    char message[ERROR_MSG_SIZE];
} error_t;

// esc
#define ESC_VERSION_NOSTREAM    -1
#define ESC_VERSION_EMPTYSTREAM -1
#define ESC_VERSION_ANY         -2

typedef struct st_esc_position esc_position_t;
typedef struct st_esc_connection_settings esc_connection_settings_t;
typedef struct st_esc_connection esc_connection_t;
typedef struct st_esc_credentials esc_credentials_t;

typedef struct st_esc_recorded_event {
    uuid_t* event_id;
    const char* event_type;
    int64_t event_number;
    const char *event_stream_id;
    int64_t created_epoch;
    buffer_t* data;
    buffer_t* metadata;
} esc_recorded_event_t;

typedef struct st_esc_resolved_event {
    esc_recorded_event_t* event;
    esc_recorded_event_t* link;
    esc_position_t* original_position;
} esc_resolved_event_t;

struct st_all_events_slice {
    char* read_direction;
    esc_position_t* from_position;
    esc_position_t* next_position;
    size_t n_events;
    esc_resolved_event_t** events;
    int is_end_of_stream;
};
typedef struct st_all_events_slice esc_all_events_slice_t;

typedef struct st_esc_write_result {
    int64_t next_expected_version;
    esc_position_t* log_position;
} esc_write_result_t;

typedef struct st_esc_event_data esc_event_data_t;

typedef struct st_esc_subscription esc_subscription_t;

typedef void (*esc_event_appeared_t)(void* ctx, esc_subscription_t* s, esc_resolved_event_t* ev);
typedef struct st_event_appeared_callback {
    esc_event_appeared_t fn;
    void* ctx;
} esc_event_appeared_callback_t;

typedef void (*esc_subscription_droppped_t)(void* ctx, esc_subscription_t* subscription, const char* reason, error_t* error);
typedef struct st_subscription_dropped_callback {
    esc_subscription_droppped_t fn;
    void* ctx;
} esc_subscription_dropped_callback_t;

esc_connection_settings_t* const esc_default_connection_settings;

// Connection
esc_connection_t* esc_connection_create(esc_connection_settings_t* connection_settings, const char* addr, const char* connection_name);
void esc_connection_destroy(esc_connection_t* conn);

int esc_connection_connect(esc_connection_t* conn);
void esc_connection_close(esc_connection_t* conn);

esc_credentials_t* esc_credentials_create(const char* username, const char* password);
void esc_credentials_destroy(esc_credentials_t* creds);

esc_event_data_t* esc_event_data_create(uuid_t* event_id, const char* event_type, bool_t is_json, buffer_t* data, buffer_t* metadata);
void esc_event_data_destroy(esc_event_data_t*);
esc_write_result_t* esc_append_to_stream(esc_connection_t* conn, const char* stream, int64_t expected_version, array_t* events);
void esc_write_result_destroy(esc_write_result_t* write_result);

esc_all_events_slice_t* esc_connection_read_all_forward(esc_connection_t* conn, esc_position_t* last_checkpoint, unsigned int count, esc_credentials_t* credentials);
void esc_all_events_slice_destroy(esc_all_events_slice_t* all_events_slice);

error_t* esc_connection_last_error(esc_connection_t* conn);

// Subscriptions
extern esc_event_appeared_callback_t esc_empty_event_appeared_callback;
extern esc_subscription_dropped_callback_t esc_empty_subscription_dropped_callback;

esc_subscription_t* esc_connection_subscribe_to_all(esc_connection_t* conn, bool_t resolve_link_tos, esc_event_appeared_callback_t event_appeared_callback, esc_subscription_dropped_callback_t subscription_dropped_callback, esc_credentials_t* credentials);
void esc_subscription_stop(esc_subscription_t* subscription);
void esc_subscription_destroy(esc_subscription_t* subscription);

// Formatting
const char* uuid_format(uuid_t* uuid, char* buf, size_t buf_size);
const char* esc_position_format(esc_position_t* position, char* buffer, size_t buf_size);

#endif //ESC_ESC_H