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

/*  Fluent Bit
 *  ==========
 *  Copyright (C) 2019      The Fluent Bit Authors
 *  Copyright (C) 2015-2018 Treasure Data Inc.
 *
 *  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_mem.h>
#include <fluent-bit/flb_output.h>
#include <fluent-bit/flb_pack.h>
#include <fluent-bit/flb_utils.h>
#include <fluent-bit/flb_time.h>
#include <msgpack.h>

#include <stdio.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>

#include "file.h"

#ifdef FLB_SYSTEM_WINDOWS
#define NEWLINE "\r\n"
#else
#define NEWLINE "\n"
#endif

struct flb_file_conf {
    const char *out_file;
    const char *delimiter;
    const char *label_delimiter;
    int  format;
};

static char* check_delimiter(const char *str)
{
    if (str == NULL) {
        return NULL;
    }

    if (!strcasecmp(str, "\\t") || !strcasecmp(str, "tab")) {
        return "\t";
    }
    else if (!strcasecmp(str, "space")) {
        return " ";
    }
    else if (!strcasecmp(str, "comma")) {
        return ",";
    }

    return NULL;
}


static int cb_file_init(struct flb_output_instance *ins,
                        struct flb_config *config,
                        void *data)
{
    const char *tmp;
    char *ret_str;
    (void) config;
    (void) data;
    struct flb_file_conf *conf;

    conf = flb_calloc(1, sizeof(struct flb_file_conf));
    if (!conf) {
        flb_errno();
        return -1;
    }

    conf->format = FLB_OUT_FILE_FMT_JSON; /* default */
    conf->delimiter = NULL;
    conf->label_delimiter = NULL;

    /* Optional output file name/path */
    tmp = flb_output_get_property("Path", ins);
    if (tmp) {
        conf->out_file = tmp;
    }

    /* Optional, file format */
    tmp = flb_output_get_property("Format", ins);
    if (tmp) {
        if (!strcasecmp(tmp, "csv")) {
            conf->format    = FLB_OUT_FILE_FMT_CSV;
            conf->delimiter = ",";
        }
        else if (!strcasecmp(tmp, "ltsv")) {
            conf->format    = FLB_OUT_FILE_FMT_LTSV;
            conf->delimiter = "\t";
            conf->label_delimiter = ":";
        }
        else if (!strcasecmp(tmp, "plain")) {
            conf->format    = FLB_OUT_FILE_FMT_PLAIN;
            conf->delimiter = NULL;
            conf->label_delimiter = NULL;
        }
        else if (!strcasecmp(tmp, "msgpack")) {
            conf->format    = FLB_OUT_FILE_FMT_MSGPACK;
            conf->delimiter = NULL;
            conf->label_delimiter = NULL;
        }
    }

    tmp = flb_output_get_property("delimiter", ins);
    ret_str = check_delimiter(tmp);
    if (ret_str != NULL) {
        conf->delimiter = ret_str;
    }

    tmp = flb_output_get_property("label_delimiter", ins);
    ret_str = check_delimiter(tmp);
    if (ret_str != NULL) {
        conf->label_delimiter = ret_str;
    }

    /* Set the context */
    flb_output_set_context(ins, conf);

    return 0;
}

static int csv_output(FILE *fp, struct flb_time *tm, msgpack_object *obj,
                      struct flb_file_conf *ctx)
{
    int i;
    int map_size;
    msgpack_object_kv *kv = NULL;

    if (obj->type == MSGPACK_OBJECT_MAP && obj->via.map.size > 0) {
        kv = obj->via.map.ptr;
        map_size = obj->via.map.size;
        fprintf(fp, "%f%s", flb_time_to_double(tm), ctx->delimiter);

        for (i = 0; i < map_size - 1; i++) {
            msgpack_object_print(fp, (kv+i)->val);
            fprintf(fp, "%s", ctx->delimiter);
        }

        msgpack_object_print(fp, (kv+(map_size-1))->val);
        fprintf(fp, NEWLINE);
    }
    return 0;
}

static int ltsv_output(FILE *fp, struct flb_time *tm, msgpack_object *obj,
                       struct flb_file_conf *ctx)
{
    msgpack_object_kv *kv = NULL;
    int i;
    int map_size;

    if (obj->type == MSGPACK_OBJECT_MAP && obj->via.map.size > 0) {
        kv = obj->via.map.ptr;
        map_size = obj->via.map.size;
        fprintf(fp, "\"time\"%s%f%s",
                ctx->label_delimiter,
                flb_time_to_double(tm),
                ctx->delimiter);

        for (i = 0; i < map_size - 1; i++) {
            msgpack_object_print(fp, (kv+i)->key);
            fprintf(fp, "%s", ctx->label_delimiter);
            msgpack_object_print(fp, (kv+i)->val);
            fprintf(fp, "%s", ctx->delimiter);
        }

        msgpack_object_print(fp, (kv+(map_size-1))->key);
        fprintf(fp, "%s", ctx->label_delimiter);
        msgpack_object_print(fp, (kv+(map_size-1))->val);
        fprintf(fp, NEWLINE);
    }
    return 0;
}

static int plain_output(FILE *fp, msgpack_object *obj, size_t alloc_size)
{
    char *buf;

    buf = flb_msgpack_to_json_str(alloc_size, obj);
    if (buf) {
        fprintf(fp, "%s" NEWLINE,
                buf);
        flb_free(buf);
    }
    return 0;
}

static void cb_file_flush(const void *data, size_t bytes,
                          const char *tag, int tag_len,
                          struct flb_input_instance *i_ins,
                          void *out_context,
                          struct flb_config *config)
{
    int ret;
    FILE * fp;
    msgpack_unpacked result;
    size_t off = 0;
    size_t last_off = 0;
    size_t alloc_size = 0;
    size_t total;
    const char *out_file;
    char *buf;
    char *tag_buf;
    msgpack_object *obj;
    struct flb_file_conf *ctx = out_context;
    struct flb_time tm;
    (void) i_ins;
    (void) config;

    /* Set the right output */
    if (!ctx->out_file) {
        out_file = tag;
    }
    else {
        out_file = ctx->out_file;
    }

    /* Open output file with default name as the Tag */
    fp = fopen(out_file, "ab+");
    if (fp == NULL) {
        flb_errno();
        FLB_OUTPUT_RETURN(FLB_ERROR);
    }

    tag_buf = flb_malloc(tag_len + 1);
    if (!tag_buf) {
        flb_errno();
        fclose(fp);
        FLB_OUTPUT_RETURN(FLB_RETRY);
    }
    memcpy(tag_buf, tag, tag_len);
    tag_buf[tag_len] = '\0';

    /*
     * Msgpack output format used to create unit tests files, useful for
     * Fluent Bit developers.
     */
    if (ctx->format == FLB_OUT_FILE_FMT_MSGPACK) {
        off = 0;
        total = 0;

        do {
            ret = fwrite((char *)data + off, 1, bytes - off, fp);
            if (ret < 0) {
                flb_errno();
                fclose(fp);
                flb_free(tag_buf);
                FLB_OUTPUT_RETURN(FLB_RETRY);
            }
            total += ret;
        } while (total < bytes);

        fclose(fp);
        flb_free(tag_buf);
        FLB_OUTPUT_RETURN(FLB_OK);
    }

    /*
     * Upon flush, for each array, lookup the time and the first field
     * of the map to use as a data point.
     */
    msgpack_unpacked_init(&result);
    while (msgpack_unpack_next(&result, data, bytes, &off) == MSGPACK_UNPACK_SUCCESS) {
        alloc_size = (off - last_off) + 128; /* JSON is larger than msgpack */
        last_off = off;

        flb_time_pop_from_msgpack(&tm, &result, &obj);

        switch (ctx->format){
        case FLB_OUT_FILE_FMT_JSON:
            buf = flb_msgpack_to_json_str(alloc_size, obj);
            if (buf) {
                fprintf(fp, "%s: [%f, %s]" NEWLINE,
                        tag_buf,
                        flb_time_to_double(&tm),
                        buf);
                flb_free(buf);
            }
            else {
                msgpack_unpacked_destroy(&result);
                fclose(fp);
                flb_free(tag_buf);
                FLB_OUTPUT_RETURN(FLB_RETRY);
            }
            break;
        case FLB_OUT_FILE_FMT_CSV:
            csv_output(fp, &tm, obj, ctx);
            break;
        case FLB_OUT_FILE_FMT_LTSV:
            ltsv_output(fp, &tm, obj, ctx);
            break;
        case FLB_OUT_FILE_FMT_PLAIN:
            plain_output(fp, obj, alloc_size);
            break;
        }
    }

    flb_free(tag_buf);
    msgpack_unpacked_destroy(&result);
    fclose(fp);

    FLB_OUTPUT_RETURN(FLB_OK);
}

static int cb_file_exit(void *data, struct flb_config *config)
{
    struct flb_file_conf *ctx = data;

    flb_free(ctx);

    return 0;
}

struct flb_output_plugin out_file_plugin = {
    .name         = "file",
    .description  = "Generate log file",
    .cb_init      = cb_file_init,
    .cb_flush     = cb_file_flush,
    .cb_exit      = cb_file_exit,
    .flags        = 0,
};