/* -*- Mode: C; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */

/*  Fluent Bit Demo
 *  ===============
 *  Copyright (C) 2015-2022 The Fluent Bit Authors
 *
 *  Licensed under the Apache License, Version 2.0 (the "License");
 *  you may not use this file except in compliance with the License.
 *  You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 *  Unless required by applicable law or agreed to in writing, software
 *  distributed under the License is distributed on an "AS IS" BASIS,
 *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 *  See the License for the specific language governing permissions and
 *  limitations under the License.
 */


#include <fluent-bit/flb_lib.h>
#include <fluent-bit/flb_mem.h>
#include <fluent-bit/flb_pipe.h>
#include <fluent-bit/flb_engine.h>
#include <fluent-bit/flb_input.h>
#include <fluent-bit/flb_output.h>
#include <fluent-bit/flb_filter.h>
#include <fluent-bit/flb_utils.h>
#include <fluent-bit/flb_time.h>
#include <fluent-bit/flb_coro.h>
#include <fluent-bit/flb_callback.h>
#include <fluent-bit/flb_kv.h>
#include <fluent-bit/flb_metrics.h>
#include <fluent-bit/flb_upstream.h>
#include <fluent-bit/flb_downstream.h>
#include <fluent-bit/tls/flb_tls.h>

#include <signal.h>
#include <stdarg.h>

#ifdef FLB_HAVE_MTRACE
#include <mcheck.h>
#endif

#ifdef FLB_HAVE_AWS_ERROR_REPORTER
#include <fluent-bit/aws/flb_aws_error_reporter.h>

struct flb_aws_error_reporter *error_reporter;
#endif

/* thread initializator */
static pthread_once_t flb_lib_once = PTHREAD_ONCE_INIT;

/* reference to the last 'flb_lib_ctx' context started through flb_start() */
FLB_TLS_DEFINE(flb_ctx_t, flb_lib_active_context);

/* reference to the last 'flb_cf' context started through flb_start() */
FLB_TLS_DEFINE(struct flb_cf, flb_lib_active_cf_context);

#ifdef FLB_SYSTEM_WINDOWS
static inline int flb_socket_init_win32(void)
{
    WSADATA wsaData;
    int err;

    err = WSAStartup(MAKEWORD(2, 2), &wsaData);
    if (err != 0) {
        fprintf(stderr, "WSAStartup failed with error: %d\n", err);
        return err;
    }
    return 0;
}
#endif

static inline struct flb_input_instance *in_instance_get(flb_ctx_t *ctx,
                                                         int ffd)
{
    struct mk_list *head;
    struct flb_input_instance *i_ins;

    mk_list_foreach(head, &ctx->config->inputs) {
        i_ins = mk_list_entry(head, struct flb_input_instance, _head);
        if (i_ins->id == ffd) {
            return i_ins;
        }
    }

    return NULL;
}

static inline struct flb_output_instance *out_instance_get(flb_ctx_t *ctx,
                                                           int ffd)
{
    struct mk_list *head;
    struct flb_output_instance *o_ins;

    mk_list_foreach(head, &ctx->config->outputs) {
        o_ins = mk_list_entry(head, struct flb_output_instance, _head);
        if (o_ins->id == ffd) {
            return o_ins;
        }
    }

    return NULL;
}

static inline struct flb_filter_instance *filter_instance_get(flb_ctx_t *ctx,
                                                              int ffd)
{
    struct mk_list *head;
    struct flb_filter_instance *f_ins;

    mk_list_foreach(head, &ctx->config->filters) {
        f_ins = mk_list_entry(head, struct flb_filter_instance, _head);
        if (f_ins->id == ffd) {
            return f_ins;
        }
    }

    return NULL;
}

void flb_init_env()
{
    flb_tls_init();
    flb_coro_init();
    flb_upstream_init();
    flb_downstream_init();
    flb_output_prepare();

    FLB_TLS_INIT(flb_lib_active_context);
    FLB_TLS_INIT(flb_lib_active_cf_context);

    /* libraries */
    cmt_initialize();
}

flb_ctx_t *flb_create()
{
    int ret;
    flb_ctx_t *ctx;
    struct flb_config *config;

#ifdef FLB_HAVE_MTRACE
    /* Start tracing malloc and free */
    mtrace();
#endif

#ifdef FLB_SYSTEM_WINDOWS
    /* Ensure we initialized Windows Sockets */
    if (flb_socket_init_win32()) {
        return NULL;
    }
#endif

    ctx = flb_calloc(1, sizeof(flb_ctx_t));
    if (!ctx) {
        perror("malloc");
        return NULL;
    }

    config = flb_config_init();
    if (!config) {
        flb_free(ctx);
        return NULL;
    }
    ctx->config = config;
    ctx->status = FLB_LIB_NONE;

    /*
     * Initialize our pipe to send data to our worker, used
     * by 'lib' input plugin.
     */
    ret = flb_pipe_create(config->ch_data);
    if (ret == -1) {
        perror("pipe");
        flb_config_exit(ctx->config);
        flb_free(ctx);
        return NULL;
    }

    /* Create the event loop to receive notifications */
    ctx->event_loop = mk_event_loop_create(256);
    if (!ctx->event_loop) {
        flb_config_exit(ctx->config);
        flb_free(ctx);
        return NULL;
    }
    config->ch_evl = ctx->event_loop;

    /* Prepare the notification channels */
    ctx->event_channel = flb_calloc(1, sizeof(struct mk_event));
    if (!ctx->event_channel) {
        perror("calloc");
        flb_config_exit(ctx->config);
        flb_free(ctx);
        return NULL;
    }

    MK_EVENT_ZERO(ctx->event_channel);

    ret = mk_event_channel_create(config->ch_evl,
                                  &config->ch_notif[0],
                                  &config->ch_notif[1],
                                  ctx->event_channel);
    if (ret != 0) {
        flb_error("[lib] could not create notification channels");
        flb_stop(ctx);
        flb_destroy(ctx);
        return NULL;
    }

    #ifdef FLB_HAVE_AWS_ERROR_REPORTER
    if (is_error_reporting_enabled()) {
        error_reporter = flb_aws_error_reporter_create();
    }
    #endif

    return ctx;
}

/* Release resources associated to the library context */
void flb_destroy(flb_ctx_t *ctx)
{
    if (!ctx) {
        return;
    }

    if (ctx->event_channel) {
        mk_event_del(ctx->event_loop, ctx->event_channel);
        flb_free(ctx->event_channel);
    }

    /* Remove resources from the event loop */
    mk_event_loop_destroy(ctx->event_loop);

    /* cfg->is_running is set to false when flb_engine_shutdown has been invoked (event loop) */
    if (ctx->config) {
        if (ctx->config->is_running == FLB_TRUE) {
            flb_engine_shutdown(ctx->config);
        }
        flb_config_exit(ctx->config);
    }

    #ifdef FLB_HAVE_AWS_ERROR_REPORTER
    if (is_error_reporting_enabled()) {
        flb_aws_error_reporter_destroy(error_reporter);
    }
    #endif

    flb_free(ctx);
    ctx = NULL;

#ifdef FLB_HAVE_MTRACE
    /* Stop tracing malloc and free */
    muntrace();
#endif
}

/* Defines a new input instance */
int flb_input(flb_ctx_t *ctx, const char *input, void *data)
{
    struct flb_input_instance *i_ins;

    i_ins = flb_input_new(ctx->config, input, data, FLB_TRUE);
    if (!i_ins) {
        return -1;
    }

    return i_ins->id;
}

/* Defines a new output instance */
int flb_output(flb_ctx_t *ctx, const char *output, struct flb_lib_out_cb *cb)
{
    struct flb_output_instance *o_ins;

    o_ins = flb_output_new(ctx->config, output, cb, FLB_TRUE);
    if (!o_ins) {
        return -1;
    }

    return o_ins->id;
}

/* Defines a new filter instance */
int flb_filter(flb_ctx_t *ctx, const char *filter, void *data)
{
    struct flb_filter_instance *f_ins;

    f_ins = flb_filter_new(ctx->config, filter, data);
    if (!f_ins) {
        return -1;
    }

    return f_ins->id;
}

/* Set an input interface property */
int flb_input_set(flb_ctx_t *ctx, int ffd, ...)
{
    int ret;
    char *key;
    char *value;
    va_list va;
    struct flb_input_instance *i_ins;

    i_ins = in_instance_get(ctx, ffd);
    if (!i_ins) {
        return -1;
    }

    va_start(va, ffd);
    while ((key = va_arg(va, char *))) {
        value = va_arg(va, char *);
        if (!value) {
            /* Wrong parameter */
            va_end(va);
            return -1;
        }
        ret = flb_input_set_property(i_ins, key, value);
        if (ret != 0) {
            va_end(va);
            return -1;
        }
    }

    va_end(va);
    return 0;
}

static inline int flb_config_map_property_check(char *plugin_name, struct mk_list *config_map, char *key, char *val)
{
    struct flb_kv *kv;
    struct mk_list properties;
    int r;

    mk_list_init(&properties);

    kv = flb_kv_item_create(&properties, (char *) key, (char *) val);
    if (!kv) {
        return FLB_LIB_ERROR;
    }

    r = flb_config_map_properties_check(plugin_name, &properties, config_map);
    flb_kv_item_destroy(kv);
    return r;
}

/* Check if a given k, v is a valid config directive for the given output plugin */
int flb_output_property_check(flb_ctx_t *ctx, int ffd, char *key, char *val)
{
    struct flb_output_instance *o_ins;
    struct mk_list *config_map;
    struct flb_output_plugin *p;
    int r;

    o_ins = out_instance_get(ctx, ffd);
    if (!o_ins) {
      return FLB_LIB_ERROR;
    }

    p = o_ins->p;
    if (!p->config_map) {
        return FLB_LIB_NO_CONFIG_MAP;
    }

    config_map = flb_config_map_create(ctx->config, p->config_map);
    if (!config_map) {
        return FLB_LIB_ERROR;
    }

    r = flb_config_map_property_check(p->name, config_map, key, val);
    flb_config_map_destroy(config_map);
    return r;
}

/* Check if a given k, v is a valid config directive for the given input plugin */
int flb_input_property_check(flb_ctx_t *ctx, int ffd, char *key, char *val)
{
    struct flb_input_instance *i_ins;
    struct flb_input_plugin *p;
    struct mk_list *config_map;
    int r;

    i_ins = in_instance_get(ctx, ffd);
    if (!i_ins) {
      return FLB_LIB_ERROR;
    }

    p = i_ins->p;
    if (!p->config_map) {
        return FLB_LIB_NO_CONFIG_MAP;
    }

    config_map = flb_config_map_create(ctx->config, p->config_map);
    if (!config_map) {
        return FLB_LIB_ERROR;
    }

    r = flb_config_map_property_check(p->name, config_map, key, val);
    flb_config_map_destroy(config_map);
    return r;
}

/* Check if a given k, v is a valid config directive for the given filter plugin */
int flb_filter_property_check(flb_ctx_t *ctx, int ffd, char *key, char *val)
{
    struct flb_filter_instance *f_ins;
    struct flb_filter_plugin *p;
    struct mk_list *config_map;
    int r;

    f_ins = filter_instance_get(ctx, ffd);
    if (!f_ins) {
      return FLB_LIB_ERROR;
    }

    p = f_ins->p;
    if (!p->config_map) {
        return FLB_LIB_NO_CONFIG_MAP;
    }

    config_map = flb_config_map_create(ctx->config, p->config_map);
    if (!config_map) {
        return FLB_LIB_ERROR;
    }

    r = flb_config_map_property_check(p->name, config_map, key, val);
    flb_config_map_destroy(config_map);
    return r;
}

/* Set an output interface property */
int flb_output_set(flb_ctx_t *ctx, int ffd, ...)
{
    int ret;
    char *key;
    char *value;
    va_list va;
    struct flb_output_instance *o_ins;

    o_ins = out_instance_get(ctx, ffd);
    if (!o_ins) {
        return -1;
    }

    va_start(va, ffd);
    while ((key = va_arg(va, char *))) {
        value = va_arg(va, char *);
        if (!value) {
            /* Wrong parameter */
            va_end(va);
            return -1;
        }

        ret = flb_output_set_property(o_ins, key, value);
        if (ret != 0) {
            va_end(va);
            return -1;
        }
    }

    va_end(va);
    return 0;
}

int flb_output_set_callback(flb_ctx_t *ctx, int ffd, char *name,
                            void (*cb)(char *, void *, void *))
{
    struct flb_output_instance *o_ins;

    o_ins = out_instance_get(ctx, ffd);
    if (!o_ins) {
        return -1;
    }

    return flb_callback_set(o_ins->callback, name, cb);
}

int flb_output_set_test(flb_ctx_t *ctx, int ffd, char *test_name,
                        void (*out_callback) (void *, int, int, void *, size_t, void *),
                        void *out_callback_data,
                        void *test_ctx)
{
    struct flb_output_instance *o_ins;

    o_ins = out_instance_get(ctx, ffd);
    if (!o_ins) {
        return -1;
    }

    /*
     * Enabling a test, set the output instance in 'test' mode, so no real
     * flush callback is invoked, only the desired implemented test.
     */

    /* Formatter test */
    if (strcmp(test_name, "formatter") == 0) {
        o_ins->test_mode = FLB_TRUE;
        o_ins->test_formatter.rt_ctx = ctx;
        o_ins->test_formatter.rt_ffd = ffd;
        o_ins->test_formatter.rt_out_callback = out_callback;
        o_ins->test_formatter.rt_data = out_callback_data;
        o_ins->test_formatter.flush_ctx = test_ctx;
    }
    else {
        return -1;
    }

    return 0;
}

/* Set an filter interface property */
int flb_filter_set(flb_ctx_t *ctx, int ffd, ...)
{
    int ret;
    char *key;
    char *value;
    va_list va;
    struct flb_filter_instance *f_ins;

    f_ins = filter_instance_get(ctx, ffd);
    if (!f_ins) {
        return -1;
    }

    va_start(va, ffd);
    while ((key = va_arg(va, char *))) {
        value = va_arg(va, char *);
        if (!value) {
            /* Wrong parameter */
            va_end(va);
            return -1;
        }

        ret = flb_filter_set_property(f_ins, key, value);
        if (ret != 0) {
            va_end(va);
            return -1;
        }
    }

    va_end(va);
    return 0;
}

/* Set a service property */
int flb_service_set(flb_ctx_t *ctx, ...)
{
    int ret;
    char *key;
    char *value;
    va_list va;

    va_start(va, ctx);

    while ((key = va_arg(va, char *))) {
        value = va_arg(va, char *);
        if (!value) {
            /* Wrong parameter */
            va_end(va);
            return -1;
        }

        ret = flb_config_set_property(ctx->config, key, value);
        if (ret != 0) {
            va_end(va);
            return -1;
        }
    }

    va_end(va);
    return 0;
}

/* Load a configuration file that may be used by the input or output plugin */
int flb_lib_config_file(struct flb_lib_ctx *ctx, const char *path)
{
    if (access(path, R_OK) != 0) {
        perror("access");
        return -1;
    }

    ctx->config->file = mk_rconf_open(path);
    if (!ctx->config->file) {
        fprintf(stderr, "Error reading configuration file: %s\n", path);
        return -1;
    }

    return 0;
}

/* This is a wrapper to release a buffer which comes from out_lib_flush() */
int flb_lib_free(void* data)
{
    if (data == NULL) {
        return -1;
    }
    flb_free(data);
    return 0;
}


/* Push some data into the Engine */
int flb_lib_push(flb_ctx_t *ctx, int ffd, const void *data, size_t len)
{
    int ret;
    struct flb_input_instance *i_ins;

    if (ctx->status == FLB_LIB_NONE || ctx->status == FLB_LIB_ERROR) {
        flb_error("[lib] cannot push data, engine is not running");
        return -1;
    }

    i_ins = in_instance_get(ctx, ffd);
    if (!i_ins) {
        return -1;
    }

    ret = flb_pipe_w(i_ins->channel[1], data, len);
    if (ret == -1) {
        flb_errno();
        return -1;
    }
    return ret;
}

static void flb_lib_worker(void *data)
{
    int ret;
    flb_ctx_t *ctx = data;
    struct flb_config *config;

    config = ctx->config;
    flb_context_set(ctx);
    mk_utils_worker_rename("flb-pipeline");
    ret = flb_engine_start(config);
    if (ret == -1) {
        flb_engine_failed(config);
        flb_engine_shutdown(config);
    }
    config->exit_status_code = ret;
    ctx->status = FLB_LIB_NONE;
}

/* Return the current time to be used by lib callers */
double flb_time_now()
{
    struct flb_time t;

    flb_time_get(&t);
    return flb_time_to_double(&t);
}

int static do_start(flb_ctx_t *ctx)
{
    int fd;
    int bytes;
    int ret;
    uint64_t val;
    pthread_t tid;
    struct mk_event *event;
    struct flb_config *config;

    pthread_once(&flb_lib_once, flb_init_env);

    flb_debug("[lib] context set: %p", ctx);

    /* set context as the last active one */

    /* spawn worker thread */
    config = ctx->config;
    ret = mk_utils_worker_spawn(flb_lib_worker, ctx, &tid);
    if (ret == -1) {
        return -1;
    }
    config->worker = tid;

    /* Wait for the started signal so we can return to the caller */
    mk_event_wait(config->ch_evl);
    mk_event_foreach(event, config->ch_evl) {
        fd = event->fd;
        bytes = flb_pipe_r(fd, &val, sizeof(uint64_t));
        if (bytes <= 0) {
#if defined(FLB_SYSTEM_MACOS)
            pthread_cancel(tid);
#endif
            pthread_join(tid, NULL);
            ctx->status = FLB_LIB_ERROR;
            return -1;
        }

        if (val == FLB_ENGINE_STARTED) {
            flb_debug("[lib] backend started");
            ctx->status = FLB_LIB_OK;
            break;
        }
        else if (val == FLB_ENGINE_FAILED) {
            flb_error("[lib] backend failed");
#if defined(FLB_SYSTEM_MACOS)
            pthread_cancel(tid);
#endif
            pthread_join(tid, NULL);
            ctx->status = FLB_LIB_ERROR;
            return -1;
        }
        else {
            flb_error("[lib] other error");
        }
    }

    return 0;
}

/* Start the engine */
int flb_start(flb_ctx_t *ctx)
{
    int ret;

    ret = do_start(ctx);
    if (ret == 0) {
        /* set context as the last active one */
        flb_context_set(ctx);
    }

    return ret;
}

/* Start the engine without setting the global context */
int flb_start_trace(flb_ctx_t *ctx)
{
    return do_start(ctx);
}

int flb_loop(flb_ctx_t *ctx)
{
    while (ctx->status == FLB_LIB_OK) {
        sleep(1);
    }
    return 0;
}

/* Stop the engine */
int flb_stop(flb_ctx_t *ctx)
{
    int ret;
    pthread_t tid;

    flb_debug("[lib] ctx stop address: %p, config context=%p\n", ctx, ctx->config);

    tid = ctx->config->worker;

    if (ctx->status == FLB_LIB_NONE || ctx->status == FLB_LIB_ERROR) {
        /*
         * There is a chance the worker thread is still active while
         * the service exited for some reason (plugin action). Always
         * wait and double check that the child thread is not running.
         */
#if defined(FLB_SYSTEM_MACOS)
        pthread_cancel(tid);
#endif
        pthread_join(tid, NULL);
        return 0;
    }

    if (!ctx->config) {
        return 0;
    }

    if (ctx->config->file) {
        mk_rconf_free(ctx->config->file);
    }

    flb_debug("[lib] sending STOP signal to the engine");

    flb_engine_exit(ctx->config);
#if defined(FLB_SYSTEM_MACOS)
    pthread_cancel(tid);
#endif
    ret = pthread_join(tid, NULL);
    if (ret != 0) {
        flb_errno();
    }
    flb_debug("[lib] Fluent Bit engine stopped");

    return ret;
}


void flb_context_set(flb_ctx_t *ctx)
{
    FLB_TLS_SET(flb_lib_active_context, ctx);
}

flb_ctx_t *flb_context_get()
{
    flb_ctx_t *ctx;

    ctx = FLB_TLS_GET(flb_lib_active_context);
    return ctx;
}

void flb_cf_context_set(struct flb_cf *cf)
{
    FLB_TLS_SET(flb_lib_active_cf_context, cf);
}

struct flb_cf *flb_cf_context_get()
{
    struct flb_cf *cf;

    cf = FLB_TLS_GET(flb_lib_active_cf_context);
    return cf;
}