#!/usr/bin/env bash

__isint='^[0-9]+$'
__isvalidstr='^[a-z0-9]+$'
__isvalidaddr='^[a-z]+$|^((25[0-5]|2[0-4]?[0-9]|1[0-9]?[0-9]|[3-9][0-9]|[0-9])\.){3}(25[0-5]|2[0-4]?[0-9]|1[0-9]?[0-9]|[3-9][0-9]|[0-9])$'

create_template() {
    curl -H "Content-Type: application/json" -X PUT "$1:$2/_index_template/papers_t" -d '
        {
            "index_patterns": ["papers*"],
            "priority": 1,
            "template": {
                "aliases": {
                    "papers": {}
                },
                "mappings": {
                    "properties": {
                        "id": {
                            "type": "keyword"
                        },
                        "title": {
                            "type": "text",
                            "analyzer": "title_analyzer"
                        },
                        "authors": {
                            "type": "text"
                        },
                        "topic": {
                            "type": "text"
                        },
                        "summary": {
                            "type": "text"
                        },
                        "tags": {
                            "type": "keyword"
                        },
                        "content": {
                            "type": "text"
                        },
                        "publisher": {
                            "type": "text"
                        }
                    }
                },
                "settings": {
                    "analysis": {
                        "analyzer": {
                            "title_analyzer": {
                                "type": "custom",
                                "tokenizer": "title_engram_tokenizer"
                            },
                            "content_analyzer_i": {
                                "type": "custom",
                                "tokenizer": "content_onchar_tokenizer",
                                "char_filter": [
                                    "markdown_token_filter"
                                ]
                            },
                            "content_analyzer_s": {
                                "type": "custom",
                                "tokenizer": "content_onchar_tokenizer",
                                "char_filter": [
                                    "markdown_token_filter"
                                ],
                                "filter": [
                                ]
                            },
                            "basic_analyzer": {

                            }
                        },
                        "tokenizer": {
                            "title_engram_tokenizer": {
                                "type": "edge_ngram",
                                "min_gram": 2,
                                "max_gram": 10,
                                "token_chars": [
                                    "letter",
                                    "digit"
                                ]
                            },
                            "content_onchar_tokenizer": {
                                "type": "char_group",
                                "tokenize_on_chars": [
                                    "whitespace",
                                    ".", ",", "(", ")", "-", "[", "]", "{", 
                                    "}", "#", ":", ";", "`", "!", "*"
                                ]
                            }
                        },
                        "char_filter": {
                            "markdown_token_filter": {
                                "type": "pattern_replace",
                                "pattern": "[[a-z][0-9]]*://[[a-z][0-9]]*.[a-z]*",
                                "replacement": ""
                            }
                        },
                        "filter": {
                        }
                    }
                }
            }
        }
    '
}

#=============================================================================================================================================================================

create_index() {
    curl -X PUT "$1:$2/papers-$3?pretty"
}

#=============================================================================================================================================================================

__usage="
    Usage: $(basename $0)
    ---------------------------------------------------------------------------
    | -c, --create-only | Skip template initialization and only create        |
    |                   | specified index. Result index name will be          |
    |                   | 'papers-{specified name}'                           |
    |                                                                         |
    |               -h  | Help information                                    |
    |                                                                         |
    |               -a  | Specifies the address                               |
    |                                                                         |
    |       -p, --port  | Specifies the port                                  |
    |                                                                         |
    | -i, --index-name  | Specifies the index name:                           |
    |                   | Must be lowercase, cannot include [\/*?\"<>| ,#:],   |
    |                   | cannot start with [.-_+], cannot be \".\" or \"..\"     |
    |                   | cannot be longer than 255 bytes (note: multi-byte   | 
    |                   | characters will count towards the limit faster)     |
    |                   | Result index name will be 'papers-{specified name}' |
    ---------------------------------------------------------------------------
"
#=============================================================================================================================================================================

CTRL=0

if [[ "$1" == "-h" ]]; then
    echo "$__usage"
else
    while [[ $# -gt 0 ]]; do
        case "$1" in
            -p | --port)
                if [[ -n "$2" && $2 =~ $__isint && "$2" -ge 1 && "$2" -le 65535 ]]; then
                    PORT="$2"
                    shift
                else 
                    echo "Invalid port number!"
                fi
                ;;
            -a | --address)
                if [[ -n "$2" ]]; then
                    IP="$2"
                    shift
                else
                    echo "Address is not specified!"
                fi
                ;;
            -i | --index-name)
                if [[ -n "$2" && $2 =~ $__isvalidstr ]]; then
                    IND="$2"
                    shift
                else 
                    echo "Index name is not specified!"
                fi
                ;;
            -c | --create-only)
                CTRL=2
                ;;
            -*)
                echo "Option '$1' is not supported"
                exit
                ;;
            *)
                if [[ $1 =~ $__isvalidaddr ]]; then
                    IP="$1"
                elif [[ $1 =~ $__isint && "$1" -ge 1 && "$1" -le 65535 ]]; then
                    PORT="$1"
                elif [[ $1 =~ $__isvalidstr ]]; then
                    IND="$1"
                else 
                    echo "Invalid argument!"
                    exit;
                fi
                ;;
        esac
        shift
    done

    echo "Specified: $IP:$PORT | Index name: $IND"

    case $CTRL in
        0) # Default behaviour - full initialization (template creation and index creation)
            create_template "$IP" "$PORT"
            echo "Elasticsearch index template created"
            create_index "$IP" "$PORT" "$IND"
            echo "Elasticsearch index (papers-$IND) created"
            exit
            ;;
        2) # Create index, skip creating the template
            create_index "$IP" "$PORT" "$IND"
            echo "Elasticsearch index (papers-$IND) created"
            exit
            ;;
    esac
fi