#
# bash autocomplete, that can work with:
# a) --help of program
#
# Also you may like:
# $ bind "set completion-ignore-case on"
# $ bind "set show-all-if-ambiguous on"
#
# It uses bash-completion dynamic loader.

# Known to work with bash 3.* with programmable completion and extended
# pattern matching enabled (use 'shopt -s extglob progcomp' to enable
# these if they are not already enabled).
shopt -s extglob

export _CLICKHOUSE_COMPLETION_LOADED=1

CLICKHOUSE_QueryProcessingStage=(
    complete
    fetch_columns
    with_mergeable_state
    with_mergeable_state_after_aggregation
)

function _clickhouse_bin_exist()
{ [ -x "$1" ] || command -v "$1" >& /dev/null; }

function _clickhouse_quote()
{
    local quoted=${1//\'/\'\\\'\'};
    printf "'%s'" "$quoted"
}

# Extract every option (everything that starts with "-") from the --help dialog.
function _clickhouse_get_options()
{
    "$@" --help 2>&1 | awk -F '[ ,=<>]' '{ for (i=1; i <= NF; ++i) { if (substr($i, 0, 1) == "-" && length($i) > 1) print $i; } }' | sort -u
}

function _complete_for_clickhouse_generic_bin_impl()
{
    local prev=$1 && shift

    case "$prev" in
        -C|--config-file|--config)
            return 1
            ;;
        --stage)
            COMPREPLY=( $(compgen -W "${CLICKHOUSE_QueryProcessingStage[*]}" -- "$cur") )
            return 1
            ;;
        --host)
            COMPREPLY=( $(compgen -A hostname -- "$cur") )
            return 1
            ;;
        # Argh...  This looks like a bash bug...
        # Redirections are passed to the completion function
        # although it is managed by the shell directly...
        '<'|'>'|'>>'|[12]'>'|[12]'>>')
            return 1
            ;;
    esac

    return 0
}

function _complete_for_clickhouse_generic_bin()
{
    local cur prev
    eval local cmd="$( _clickhouse_quote "$1" )"
    _clickhouse_bin_exist "$cmd" || return 0

    COMPREPLY=()
    _get_comp_words_by_ref cur prev

    if _complete_for_clickhouse_generic_bin_impl "$prev"; then
        COMPREPLY=( $(compgen -W "$(_clickhouse_get_options "$cmd")" -- "$cur") )
    fi

    return 0
}

function _complete_clickhouse_generic()
{
    local bin=$1 && shift
    local f=${1:-_complete_for_clickhouse_generic_bin}
    local o=(
        -o default
        -o bashdefault
        -o nospace
        -F "$f"
        "$bin"
    )
    complete "${o[@]}"
}

function _complete_clickhouse_bootstrap_main()
{
    local runtime=/usr/share/bash-completion/bash_completion
    if ! type _get_comp_words_by_ref >& /dev/null && [[ -f $runtime ]]; then
        source $runtime
    fi
    type _get_comp_words_by_ref >& /dev/null || return 0
}
_complete_clickhouse_bootstrap_main "$@"