# mutt completion                                          -*- shell-script -*-
#
# Mutt doesn't have an "addressbook" like Pine, but it has aliases and
# a "query" function to retrieve addresses, so that's what we use here.

# @param $1 (cur) Current word to complete
_muttaddr()
{
    _muttaliases "$1"
    _muttquery "$1"

    COMPREPLY+=($(compgen -u -- "$1"))
}

# Find muttrc to use
# @output  muttrc filename
_muttrc()
{
    # Search COMP_WORDS for '-F muttrc' or '-Fmuttrc' argument
    set -- "${words[@]}"
    while (($# > 0)); do
        if [[ $1 == -F* ]]; then
            if ((${#1} > 2)); then
                muttrc="$(dequote "${1:2}")"
            else
                shift
                [[ $1 ]] && muttrc="$(dequote "$1")"
            fi
            break
        fi
        shift
    done

    if [[ ! -v muttrc ]]; then
        if [[ -f ~/.${muttcmd}rc ]]; then
            muttrc=\~/.${muttcmd}rc
        elif [[ -f ~/.${muttcmd}/${muttcmd}rc ]]; then
            muttrc=\~/.${muttcmd}/${muttcmd}rc
        fi
    fi
    printf "%s" "${muttrc-}"
}

# Recursively build list of sourced config files
# @param $1  List of config files found so far
# @param $2  Config file to process
# @output  List of config files
_muttconffiles()
{
    local file sofar
    local -a newconffiles

    sofar=" $1 "
    shift
    while [[ ${1-} ]]; do
        newconffiles=($(command sed -n 's|^source[[:space:]]\{1,\}\([^[:space:]]\{1,\}\).*$|\1|p' "$(eval printf %s $1)"))
        for file in ${newconffiles+"${newconffiles[@]}"}; do
            __expand_tilde_by_ref file
            [[ ! -f $file || $sofar == *\ $file\ * ]] && continue
            sofar+=" $file"
            sofar=" $(eval _muttconffiles \"$sofar\" $file) "
        done
        shift
    done
    printf '%s\n' $sofar
}

# @param $1 (cur) Current word to complete
_muttaliases()
{
    local cur=$1 muttrc muttcmd=${words[0]}
    local -a conffiles aliases

    muttrc=$(_muttrc)
    [[ -z $muttrc ]] && return

    conffiles=($(eval _muttconffiles $muttrc $muttrc))
    # shellcheck disable=SC2046
    aliases=("$(command sed -n 's|^alias[[:space:]]\{1,\}\([^[:space:]]\{1,\}\).*$|\1|p' \
        $(eval echo "${conffiles[@]}"))")
    COMPREPLY+=($(compgen -W "${aliases[*]}" -- "$cur"))
}

# @param $1 (cur) Current word to complete
_muttquery()
{
    local cur=$1 querycmd muttcmd=${words[0]}
    local -a queryresults

    querycmd="$($muttcmd -Q query_command 2>/dev/null | command sed -e 's|^query_command=\"\(.*\)\"$|\1|' -e 's|%s|'$cur'|')"
    if [[ -z $cur || -z $querycmd ]]; then
        queryresults=()
    else
        __expand_tilde_by_ref querycmd
        queryresults=($($querycmd |
            command sed -n '2,$s|^\([^[:space:]]\{1,\}\).*|\1|p'))
    fi

    COMPREPLY+=($(compgen -W "${queryresults[*]}" -- "$cur"))
}

# @param $1 (cur) Current word to complete
_muttfiledir()
{
    local cur=$1 folder muttrc spoolfile muttcmd=${words[0]}

    muttrc=$(_muttrc)
    if [[ $cur == [=+]* ]]; then
        folder="$($muttcmd -F "$muttrc" -Q folder 2>/dev/null | command sed -e 's|^folder=\"\(.*\)\"$|\1|')"
        : folder:=~/Mail

        # Match any file in $folder beginning with $cur
        # (minus the leading '=' sign).
        compopt -o filenames
        COMPREPLY=($(compgen -f -- "$folder/${cur:1}"))
        COMPREPLY=(${COMPREPLY[@]#$folder/})
        return
    elif [[ $cur == !* ]]; then
        spoolfile="$($muttcmd -F "$muttrc" -Q spoolfile 2>/dev/null |
            command sed -e 's|^spoolfile=\"\(.*\)\"$|\1|')"
        [[ -n $spoolfile ]] && eval cur="${cur/^!/$spoolfile}"
    fi
    _filedir
}

_mutt()
{
    local cur prev words cword
    _init_completion -n =+! || return

    case $cur in
        -*)
            COMPREPLY=($(compgen -W '-A -a -b -c -e -f -F -H -i -m -n -p -Q -R -s
            -v -x -y -z -Z -h' -- "$cur"))
            return
            ;;
        *)
            case $prev in
                -*[afFHi])
                    _muttfiledir "$cur"
                    return
                    ;;
                -*A)
                    _muttaliases "$cur"
                    return
                    ;;
                -*[emQshpRvyzZ])
                    return
                    ;;
                *)
                    _muttaddr "$cur"
                    return
                    ;;
            esac
            ;;
    esac
} &&
    complete -F _mutt -o default mutt muttng

# ex: filetype=sh
