#!/bin/bash

tempfile="$(tempfile)"

# how can I get the --graph with only the desired commits?

if ! editor="$(git config --get git-rebasei-editor.editor)"; then
    editor="${EDITOR:-editor}"
fi


if [ "$editor" == "emacs" ]; then
    force_color=--color=always
else
    force_color=""
fi

esccolor="\(\|`printf '\033\[[0-9;]*m\)'`"

process_input_lines() {
    while IFS=$'\n' read line; do
        if [[ "$line" =~ ^( *#) ]]; then
            : # TODO: should print the comments inline, and move the first block of comments to the end.
        elif [[ "$line" =~ ^( *)$ ]]; then
            echo "$line"
        elif [ "${line:0:5}" = "exec " ]; then
            echo "$line"
        elif [[ "$line" =~ ^([^# ]+ +)([^ ]+)( +.*)$ ]]; then
            # TODO: try to recreate a --graph, if possible?
            # This would require advanced editing of the history, however.
            echo -n "${BASH_REMATCH[1]}"
            git log -1 --oneline --decorate --name-status $force_color \
                "${BASH_REMATCH[2]}" -- \
            | sed -e '2,$ s/^/| /'
        else
            echo "#??# $line"
        fi
    done
}

# The sed command discards the blank lines at the beginning
cat "$1" \
    | tac \
    | process_input_lines \
    | sed -r -n -e '/^.+$/,$p' \
    > "$tempfile"

# with --graph, if there are actually any pipes, use (+ color handling):
# | sed -e 's~^\([ |\\/*]* \)\([0-9a-f][0-9a-f]* \)~\1pick \2~' \

echo >> "$tempfile"
echo "## Originial git rebase -i data:" >> "$tempfile"
cat "$1" | sed -e 's/^/## /' -e "s/^## $//" -e "s/^## #/#/" >> "$tempfile"

if [ "$editor" == "emacs" ]; then
    emacs --eval "(with-current-buffer (find-file \"$tempfile\") (require 'ansi-color) (ansi-color-apply-on-region (point-min) (point-max)) (save-buffer))"
else
    # Allow spaces in the git-rebasei-editor.editor config and in $EDITOR
    # TODO: check that the spaces can actually be present in $EDITOR
    $editor "$tempfile"
fi

# p, pick
# r, reword
# e, edit
# s, squash
# f, fixup
# x, exec
# d, drop

commands='p\|pick\|r\|reword\|e\|edit\|s\|squash\|f\|fixup\|x\|exec\|d\|drop'

cat "$tempfile" \
    | grep -v "^#" \
    | grep -v "^ *[|\\/][ |\\/]*[^|\\/*]" \
    | tac \
    | sed -e 's~^\([ |\\/*]* \)\(\('"$commands"'\)[0-9a-f][0-9a-f]* \)~\2~' \
    | tee "$1" >&2