# truncates a string on the left
# $1: string to truncate
# $2: maximum length
# $3: truncation string replacement (optional)
# $4: separator symbol (optional, prevents truncation of rightmost item)
__truncate_left() {
    local str="$1"
    local maxlen="$2"
    local trunc_symbol="$3"
    local sep_symbol="$4"

    # get minimum length to not truncate a long name
    if [ -n "$sep_symbol" ]
    then
        local component=${1##*$sep_symbol}
        maxlen=$(( ( maxlen < ${#component} ) ? ${#component} : maxlen ))
    fi

    # truncation point
    local offset=$(( ${#str} - maxlen ))

    if [ ${offset} -gt "0" ]
    then
        #truncation is needed
        str=${str:$offset:$maxlen}  #truncate
        str=${trunc_symbol}/${str#*/}  #add symbol
    fi
    echo "$str"
}

# truncates a path
__truncate_path() {
    #gain some place with '~'
    local path=${1/#$HOME/\~}
    __truncate_left "$path" 25 '…' '/'
}

# truncates CWD
__tpwd() {
    __truncate_path "$PWD"
}

clear_incomplete_line() {
    # ask for cursor position
    echo -en "\033[6n"
    # read answer
    IFS=';' read -r -d R -a pos
    # extract tput-compatible answer
    local row=$((${pos[0]:2} - 1))
    local col=$((${pos[1]} - 1))
    # move back over terminal answer echo, which will hopefully be overwritten
    tput cup $row $col

    # not on first column? clean up! (overwrites answer)
    # we print a terminal width worth of columns, but since 
    # it goes too far, we backtrack with CR
    [[ $col != 0 ]] && printf "\e[7m%%\e[m%*s\r" $((COLUMNS-1))
    # else e.g prompt will overwrite answer echo
}

# git prompt info
source $DOTFILES_BASH_DIR/git_prompt_info
GIT_PS1_SHOWDIRTYSTATE=1
GIT_PS1_SHOWSTASHSTATE=1
GIT_PS1_SHOWUNTRACKEDFILES=1

# dynamic prompt
set_prompt() {
    # save last command exit code (requires set_prompt to be first in PROMPT_COMMAND)
    local last_exit_code="$?"

    # load color vars
    source "$DOTFILES_BASH_DIR/ansi_colors"

    # set up git status env vars
    __git_ps1_vars

    # build prompt
    PS1=""

    # opening + user@host
    PS1+="${B}[${UC}\u@\h"

    # git?
    if [[ -n "${GIT_PS1_NAME-}" ]]; then
        # basic info
        PS1+=" ${Y}${GIT_PS1_NAME}"
        [[ "$GIT_PS1_STATUS" == *b* ]] && PS1+="${NONE}›"
        PS1+="${NONE}›${B}${GIT_PS1_BRANCH}"
        [[ "$GIT_PS1_STATUS" == *g* ]] && PS1+="${NONE}›"
        PS1+="${NONE}›${G}${GIT_PS1_PREFIX}"

        # status symbols
        local status=""
        [[ "$GIT_PS1_STATUS" == *h* ]] && status+="${NONE}↰"
        [[ "$GIT_PS1_STATUS" == *t* ]] && status+="${R}!"
        [[ "$GIT_PS1_STATUS" == *u* ]] && status+="${Y}≠"
        [[ "$GIT_PS1_STATUS" == *s* ]] && status+="${R}±"
        [[ "$GIT_PS1_STATUS" == *n* ]] && status+="${BB}∅"
        [[ -n "$status" ]] && PS1+=" ${status}"

        # action info
        local action=""
        [[ "$GIT_PS1_STATUS" == *R* ]] && action+=" rebase"
        [[ "$GIT_PS1_STATUS" == *i* ]] && action+="-i"
        [[ "$GIT_PS1_STATUS" == *A* ]] && action+=" apply"
        [[ "$GIT_PS1_STATUS" == *M* ]] && action+=" merge"
        [[ "$GIT_PS1_STATUS" == *B* ]] && action+=" bisect"
        [[ -n "$action" ]] && PS1+="${R}${action}"
    else
        # no git => just a smartly truncated path
        PS1+=" ${G}$(__tpwd)"
    fi

    # exit code
    [[ $last_exit_code -ne 0 ]] && PS1+=" ${BW}↪${last_exit_code}"

    # closing prompt
    PS1+="${B}]"
    PS1+="${UC}\\$ ${NONE}"
}

# vim: ft=sh