#!/bin/sh

repo_status_git() {
	BRANCH_NAME="$(git rev-parse --abbrev-ref HEAD)"
	OUT="$(git status --short --branch --porcelain)"
	BRANCH_LINE="$(echo "$OUT" | head -n 1)"
	DIFF_LINES="$(echo "$OUT" | tail -n +2)"

	IS_AHEAD=false
	IS_BEHIND=false
	if echo "$BRANCH_LINE" | grep -q 'ahead'; then
		IS_AHEAD=true
	fi
	if echo "$BRANCH_LINE" | grep -q 'behind'; then
		IS_BEHIND=true
	fi

	LINE=''

	if [ "$IS_AHEAD" = true ] && [ "$IS_BEHIND" = true ]; then
		LINE="^^^ $BRANCH_NAME vvv"
	elif [ "$IS_AHEAD" = true ]; then
		LINE="^ $BRANCH_NAME ^"
	elif [ "$IS_BEHIND" = true ]; then
		LINE="v $BRANCH_NAME v"
	else
		LINE="$BRANCH_NAME"
	fi

	HAS_DIFF=false
	HAS_UNTRACKED=false
	if echo "$DIFF_LINES" | grep -q '^[A|D|M| ][M|D| ]'; then
		HAS_DIFF=true
	fi
	if echo "$DIFF_LINES" | grep -q '^[?][?]'; then
		HAS_UNTRACKED=true
	fi

	if [ "$HAS_DIFF" = true ]; then
		COLOR_FN=redb
		LINE="{$LINE}"
	elif [ "$IS_AHEAD" = true ] || [ "$IS_BEHIND" = true ]; then
		COLOR_FN=bluei
		LINE="[$LINE]"
	elif [ "$HAS_UNTRACKED" = true ]; then
		COLOR_FN=lightblue
		LINE="{$LINE}"
	else
		COLOR_FN=green
		LINE="($LINE)"
	fi

	color -c "$COLOR_FN" "$LINE"

	BRANCH_COUNT="$(git branch --list | wc -l)"
	if [ "$BRANCH_COUNT" -gt 1 ]; then
		color -c lightblue "<$BRANCH_COUNT>"
	fi

	STASH_COUNT="$(git stash list | wc -l)"
	if [ "$STASH_COUNT" != 0 ]; then
		color -c red "*$STASH_COUNT"
	fi

	color -c blacki " - git/$(git rev-parse HEAD)"
}

repo_status_fossil() {
	BRANCH_NAME="$(fossil branch current)"

	if [ -n "$(fossil extras)" ]; then
		HAS_UNTRACKED=1
	fi

	BRANCH_MARKER="$BRANCH_NAME"

	if [ -n "${HAS_UNTRACKED:-}" ]; then
		COLOR_FN=lightblue
		LINE="($BRANCH_MARKER)"
	else
		COLOR_FN=green
		LINE="($BRANCH_MARKER)"
	fi

	color -c "$COLOR_FN" "$LINE"

	color -c blacki " - fossil/$(fossil info | awk '/^checkout:/ { print $2 }')"
}

repo_status_mercurial() {
	BRANCH_NAME="$(hg branch)"
}

repo_status() {
	dir="$(basename "$PWD")"
	if   [ -d .git ]; then
		repo_status_git
	elif [ -f "$dir.fossil" ]; then
		repo_status_fossil
	elif [ -d .hg ]; then
		repo_status_mercurial
	fi
}


error_marker() {
	STATUS=$?
	if [ "$STATUS" != 0 ]; then
		color -c redb " (!! $STATUS !!) "
	fi
}

shell_level() {
	if [ -n "${SHLVL:-}" ]; then
		if [ -n "${TMUX:-}" ]; then
			LVL=$((SHLVL - 1))
		else
			LVL="$SHLVL"
		fi
		if [ "$LVL" != 1 ]; then
			color -c white "[$LVL] "
		fi
	fi
}

timestamp() {
	color -c blacki '\T'
}

path() {
	color -c yellowb '\w/'
}

guix_env() {
	if [ "$GUIX_ENVIRONMENT" != '' ]; then
		printf '\n'
		color -c blacki '~> '
		color -c purple 'guix environment '
		printf '('
		color -c blueb "$GUIX_ENVIRONMENT"
		printf ')'
	fi
}

in_nix_shell() {
	if [ "$IN_NIX_SHELL" != '' ]; then
		printf '\n'
		color -c blacki '~> '
		color -c purpleb "$IN_NIX_SHELL "
		color -c purple 'nix-shell '
		printf '('
		color -c blueb "${name:-}"
		printf ')'
	fi
}

PS1='`error_marker`'$(timestamp)' '$(path)' `shell_level``repo_status``guix_env``in_nix_shell`
$ '


vcs_status() {
	git status "$@"
}

vcs_diff() {
	git diff "$@"
}

vcs_diff_staged() {
	git diff --staged "$@"
}