#!/bin/sh
# shellcheck disable=1090,2153
set -eu

usage() {
	cat <<-'EOF'
		Usage:
		  mailcfg ACTION
		  mailcfg -h
	EOF
}

help() {
	cat <<-'EOF'

		Options:
		  -h, --help    show this message

		  ACTION        one of:
		                - mbsync
		                - msmtp
		                - notmuchcfg
		                - notmuchhook
		                - alot


		Emit the generated configuration file for the chosen email
		program.  Get the configuration files from
		$XDG_CONFIG_HOME/mailcfg/*.env, where every *.env file is a
		shell script that defines the variables used in this program:
		- $NAME
		- $LABEL
		- $IMAP
		- $SMTP
		- $ADDR

		One of the files also needs to define:
		- $DEFAULT_NAME
		- $DEFAULT_ADDR
		- $DEFAULT_LABEL

		An example of such file could be "30-andre@work.com.env":

		  #!/bin/sh
		  set -eu


		  NAME='André!'
		  LABEL='Work'
		  IMAP='imap.work.com'
		  SMTP='smtp.work.com'
		  ADDR='andre@work.com'


		Examples:

		  Get the alot configuration file:

		    $ mailcfg alot
	EOF
}


for flag; do
	case "$flag" in
		--)
			break
			;;
		--help)
			usage
			help
			exit
			;;
		*)
			;;
	esac
done

while getopts 'h' flag; do
	case "$flag" in
		h)
			usage
			help
			exit
			;;
		*)
			usage >&2
			exit 2
			;;
	esac
done
shift $((OPTIND - 1))

ACTION="${1:-}"
eval "$(assert-arg "$ACTION" 'ACTION')"

CFGDIR="${XDG_CONFIG_HOME:-$HOME/.config}/mailcfg"


mbsync() {
	cat <<-'EOF'
		SyncState *
		Create Both
		Expunge Both
		Remove Both
		Sync All
	EOF

	for env in "$CFGDIR"/*.env; do
		. "$env"
		cat <<-EOF


			## $LABEL

			IMAPAccount $LABEL
			Host $IMAP
			User $ADDR
			PassCmd "pass show $ADDR"
			SSLType IMAPS

			IMAPStore ${LABEL}Remote
			Account   $LABEL

			MaildirStore ${LABEL}Local
			Path  ~/Maildir/$LABEL/
			Inbox ~/Maildir/$LABEL/INBOX
			SubFolders Verbatim

			Channel ${LABEL}Folders
			Far    :${LABEL}Remote:
			Near   :${LABEL}Local:
			Patterns *

			Group   $LABEL
			Channel ${LABEL}Folders
		EOF
	done
}

msmtp() {
	cat <<-'EOF'
		defaults
		 auth on
		 tls on
		 port 587
		 syslog on
		 logfile ~/.local/var/log/msmtp
	EOF

	for env in "$CFGDIR"/*.env; do
		. "$env"
		cat <<-EOF

			account $LABEL
			 host $SMTP
			 from $ADDR
			 user $ADDR
			 passwordeval pass show $ADDR
		EOF
	done

	cat <<-EOF

		account default : $DEFAULT_LABEL
	EOF
}

notmuchcfg() {
	for env in "$CFGDIR"/*.env; do
		. "$env"
	done

	cat <<-EOF
		[user]
		name = $DEFAULT_NAME
		primary_email = $DEFAULT_ADDR
	EOF

	printf 'other_email = '
	for env in "$CFGDIR"/*.env; do
		. "$env"
		if [ "$ADDR" = "$DEFAULT_ADDR" ]; then
			continue
		fi
		echo "$ADDR"
	done | paste -sd';'

	cat <<-'EOF'

		[new]
		tags = new;
		ignore = .mbsyncstate;.uidvalidity

		[search]
		exclude_tags = deleted;spam

		[maildir]
		synchronize_flags = true
	EOF
}

notmuchhook() {
	LABELS=''
	for env in "$CFGDIR"/*.env; do
		. "$env"
		if [ -z "$LABELS" ]; then
			LABELS="$LABEL"
		else
			LABELS="$LABELS $LABEL"
		fi
	done
	sed \
		-e "s|@DIRS@|$LABELS|g" \
		-e "s|@DEFAULT_LABEL@|$DEFAULT_LABEL|g" \
		"$CFGDIR"/post-new
}

alot() {
	cat <<-'EOF'
		attachment_prefix = "~/Downloads/"

		[bindings]
		  i = toggletags inbox
		  I = search folder:/INBOX/ AND NOT tag:killed AND NOT tag:archive
	EOF
	echo "
		z archive
		s spam
		u unread
		r keep
		t track
	" | while read -r l; do
		if [ -z "$l" ]; then
			continue
		fi
		LC="$( echo "$l" | cut -d' ' -f1)"
		TAG="$(echo "$l" | cut -d' ' -f2)"
		UC="$(echo "$LC" | tr '[:lower:]' '[:upper:]')"
		cat <<-EOF
			  $LC = toggletags $TAG
			  $UC = search tag:$TAG AND NOT tag:killed
		EOF
	done

	cat <<-'EOF'
		  M = search folder:/lists/ AND NOT tag:killed
		  m = compose --tags inbox
		  [[thread]]
		    v = pipeto urlscan 2>/dev/null
		    V = pipeto 'gpg -d | less'
		    r = reply --all
		    R = reply
		    ' ' = fold; untag unread; move next unfolded
		    P = pipeto 'git am'

		[accounts]
	EOF

	for env in "$CFGDIR"/*.env; do
		. "$env"
		cat <<-EOF
			  [[$LABEL]]
			    realname = $NAME
			    address = $ADDR
			    sendmail_command = msmtpq --account=$LABEL -t
			    sent_box = maildir://~/Maildir/$LABEL/Sent
			    draft_box = maildir://~/Maildir/$LABEL/Drafts
			    gpg_key = 5BDAE9B8B2F6C6BCBB0D6CE581F90EC3CD356060
		EOF
	done
}


case "$ACTION" in
	mbsync|msmtp|notmuchcfg|notmuchhook|alot)
		"$1"
		;;
	*)
		printf 'Unsupported ACTION: "%s".\n\n' "$ACTION" >&2
		usage >&2
		exit 2
		;;
esac