#!/bin/bash

# Log output:
#
# * 51c333e    (12 days)    <Gary Bernhardt>   add vim-eunuch
#
# The time massaging regexes start with ^[^<]* because that ensures that they
# only operate before the first "<". That "<" will be the beginning of the
# author name, ensuring that we don't destroy anything in the commit message
# that looks like time.
#
# The log format uses } characters between each field, and `column` is later
# used to split on them. A } in the commit subject or any other field will
# break this.

HASH="%C(12)%h%Creset"
RELATIVE_TIME="%C(7)(%ar)%Creset"
AUTHOR="%C(249)<%an>%Creset"
REFS="%C(magenta)%d%Creset"
SUBJECT="%C(245)%s"

FORMAT="$HASH}$RELATIVE_TIME}$AUTHOR}$REFS $SUBJECT"

ANSI_BLACK='\033[30m'
ANSI_BLACK_BOLD='\033[0;30;1m'
ANSI_RED='\033[31m'
ANSI_RED_BOLD='\033[0;31;1m'
ANSI_GREEN='\033[32m'
ANSI_GREEN_BOLD='\033[0;32;1m'
ANSI_YELLOW='\033[33m'
ANSI_YELLOW_BOLD='\033[0;33;1m'
ANSI_BLUE='\033[34m'
ANSI_BLUE_BOLD='\033[0;34;1m'
ANSI_MAGENTA='\033[35m'
ANSI_MAGENTA_BOLD='\033[0;35;1m'
ANSI_CYAN='\033[36m'
ANSI_CYAN_BOLD='\033[0;36;1m'
ANSI_WHITE='\033[37m'
ANSI_WHITE_BOLD='\033[0;37;1m'
ANSI_RESET='\033[0m'

BLUE_GRAY='\033[0;38;5;12m'
BR_YELLOW='\033[0;38;5;3m'

show_git_head() {
    pretty_git_log -1
    git show -p --pretty="tformat:"
}

pretty_git_log() {
    git log --graph --pretty="tformat:${FORMAT}" $* |
        # Replace (2 years ago) with (2 years)
        sed -Ee 's/(^[^<]*) ago\)/\1)/' |
        # Replace (2 years, 5 months) with (2 years)
        sed -Ee 's/(^[^<]*), [[:digit:]]+ .*months?\)/\1)/' |
        # Line columns up based on } delimiter
        column -s '}' -t |
        # Color merge commits specially
        sed -Ee "s/(Merge (branch|remote-tracking branch|pull request) .*$)/$(printf $BR_YELLOW)\1$(printf $ANSI_RESET)/" |
        # Page only if we're asked to.
        if [ -n "$GIT_NO_PAGER" ]; then
            cat
        else
            # Page only if needed.
            less --quit-if-one-screen --no-init --RAW-CONTROL-CHARS --chop-long-lines
        fi
}