From 228c930ffd2697cfbed0aecf8f25ffcd58733cde Mon Sep 17 00:00:00 2001
From: Case Duckworth
Date: Mon, 1 Jun 2020 14:58:51 -0500
Subject: Add rudimentary history support.

This commit adds `history_init`, `history_append`, `history_back`, and
`history_forward` functions.

The history is implemented as an array, HISTORY, which is appended to
with history_append when pages are visited, and a pointer, HN, which
points to the current position in the array.  When history_back is
called, it moves the pointer back 2 and calls blastoff to the URL there.
When history_forward is called, it does not move the pointer and
blastsoff to the URL.  Why back and forward basically have an off-by-one
error is beyond me at this time.

ISSUES:
- if the user goes back then forward, the history is not rewritten for
later URLs. for example, if the history is

	1.gmi	2.gmi	3.gmi*

where the * indicates the current history position, when the user goes
back 2, it looks like this:

	1.gmi*	2.gmi	3.gmi

if the user then navigates to another page:

	1.gmi	4.gmi*	3.gmi

3.gmi is still in the history, so the user can go forward from 4.  This
is unexpected as far as every other client that I know of goes.
---
 bollux | 52 +++++++++++++++++++++++++++++++++++++++++++---------
 1 file changed, 43 insertions(+), 9 deletions(-)

diff --git a/bollux b/bollux
index 5b41cda..06e5403 100755
--- a/bollux
+++ b/bollux
@@ -66,6 +66,7 @@ log() {
 bollux() {
 	run bollux_config
 	run bollux_args "$@"
+	run history_init
 
 	if [[ ! "${BOLLUX_URL:+isset}" ]]; then
 		run prompt GO BOLLUX_URL
@@ -307,7 +308,7 @@ request_url() {
 }
 
 handle_response() {
-	local url="$1" code meta
+	local URL="$1" code meta
 
 	while read -r -d $'\r' hdr; do
 		code="$(gawk '{print $1}' <<<"$hdr")"
@@ -322,14 +323,14 @@ handle_response() {
 	case "$code" in
 	1*)
 		REDIRECTS=0
-		BOLLUX_URL="$URL"
+		run history_append "$URL"
 		run prompt "$meta" QUERY
 		# shellcheck disable=2153
 		run blastoff "?$QUERY"
 		;;
 	2*)
 		REDIRECTS=0
-		BOLLUX_URL="$URL"
+		run history_append "$URL"
 		run display "$meta"
 		;;
 	3*)
@@ -337,7 +338,6 @@ handle_response() {
 		if ((REDIRECTS > BOLLUX_MAXREDIR)); then
 			die $((100 + code)) "Too many redirects!"
 		fi
-		BOLLUX_URL="$URL"
 		run blastoff "$meta"
 		;;
 	4*)
@@ -368,7 +368,6 @@ display() {
 	mime="$(trim "${hdr[0],,}")"
 	for ((i = 1; i <= "${#hdr[@]}"; i++)); do
 		h="$(trim "${hdr[$i]}")"
-		log d "'$h'"
 		case "$h" in
 		charset=*) charset="${h#charset=}" ;;
 		esac
@@ -590,10 +589,16 @@ handle_keypress() {
 		run blastoff -u "$URL"
 		;;
 	50) # [ - back in the history
-		run history_back
+		run history_back || {
+			sleep 0.5
+			run blastoff "$BOLLUX_URL"
+		}
 		;;
 	51) # ] - forward in the history
-		run history_forward
+		run history_forward || {
+			sleep 0.5
+			run blastoff "$BOLLUX_URL"
+		}
 		;;
 	52) # r - re-request the current resource
 		run blastoff "$BOLLUX_URL"
@@ -643,8 +648,37 @@ download() {
 	fi
 }
 
-history_back() { log error "Not implemented."; }
-history_forward() { log error "Not implemented."; }
+history_init() {
+	declare -a HISTORY # history is kept in an array
+	HN=0               # position of history in the array
+}
+
+history_append() { # history_append URL
+	BOLLUX_URL="$1"
+	HISTORY[$HN]="$BOLLUX_URL"
+	log d "HN=$HN HISTORY: ${HISTORY[*]}"
+	((HN += 1))
+}
+
+history_back() {
+	log d "HN=$HN"
+	((HN -= 2))
+	if ((HN <= 0)); then
+		HN=0
+		log e "Beginning of history."
+		return 1
+	fi
+	blastoff "${HISTORY[$HN]}"
+}
+history_forward() {
+	log d "HN=$HN"
+	if ((HN >= ${#HISTORY[@]})); then
+		HN="${#HISTORY[@]}"
+		log e "End of history."
+		return 1
+	fi
+	blastoff "${HISTORY[$HN]}"
+}
 
 if [[ "${BASH_SOURCE[0]}" == "$0" ]]; then
 	run bollux "$@"
-- 
cgit 1.4.1-21-gabe81