#!/bin/bash

HAPROXY_CFG_DIR="/etc/haproxy"
HAPROXY_CFG="$HAPROXY_CFG_DIR/haproxy.cfg"
HAPROXY_SERVICE_DIR="$HAPROXY_CFG_DIR/services"

set -e

sudo mkdir -p $HAPROXY_SERVICE_DIR

sudo cp $HAPROXY_CFG $HAPROXY_CFG.bak

AUTOCONFIG_BEGIN="# === BEGIN autoconfig ==="
AUTOCONFIG_END="# === END autoconfig ==="
sudo sed -i "/$AUTOCONFIG_BEGIN/,/$AUTOCONFIG_END/d" $HAPROXY_CFG

echo "$AUTOCONFIG_BEGIN" | sudo tee -a $HAPROXY_CFG > /dev/null

if [ -z "$(ls -A $HAPROXY_SERVICE_DIR 2>/dev/null)" ]; then
    echo "No services found under $HAPROXY_SERVICE_DIR. Skipping autoconfig."
    echo "$AUTOCONFIG_END" | sudo tee -a $HAPROXY_CFG > /dev/null
    sudo systemctl restart haproxy
    exit 0
fi

# general http redirect
echo "Generating http redirect config.."
HTTP_REDIRECT=$(cat <<EOF
# === BEGIN autoconfig redirect ===
frontend http_redirect
    bind *:80
    http-request redirect scheme https code 301
# === END autoconfig redirect ===
EOF
)
echo "$HTTP_REDIRECT" | sudo tee -a $HAPROXY_CFG > /dev/null

# Frontend https config
echo "Generating frontend https config.."
HTTPS_BEGIN="# === BEGIN autoconfig https ==="
HTTPS_END="# === END autoconfig https ==="
BIND_LINE="    bind *:443 ssl"

for cert_file in $HAPROXY_SERVICE_DIR/*/cert.block; do
    while IFS= read -r line; do
        [[ -z "$line" || "$line" == \#* ]] && continue
        BIND_LINE+=" $line"
    done < "$cert_file"
done
BIND_LINE+=" alpn h2,http/1.1"

ACL_BLOCK=""
for acl_file in $HAPROXY_SERVICE_DIR/*/acl.block; do
    while IFS= read -r line; do
        [[ -z "$line" ]] && continue
        ACL_BLOCK+="    $line"$'\n'
    done < "$acl_file"
done

HTTPS_CONFIG=$(cat <<EOF
$HTTPS_BEGIN
frontend https
$BIND_LINE
    mode http
$ACL_BLOCK
$HTTPS_END
EOF
)

echo "$HTTPS_CONFIG" | sudo tee -a $HAPROXY_CFG > /dev/null

# Per service backend config
echo "Generating per service backend config"
BACKEND_BEGIN="# === BEGIN autoconfig backends ==="
BACKEND_END="# === END autoconfig backends ==="

BACKEND_BLOCK=""

for backend_file in $HAPROXY_SERVICE_DIR/*/backend.block; do
    while IFS= read -r line; do
        BACKEND_BLOCK+="$line"$'\n'
    done < "$backend_file"
    BACKEND_BLOCK+=$'\n'
done
BACKEND_CONFIG=$(cat <<EOF
$BACKEND_BEGIN
$BACKEND_BLOCK
$BACKEND_END
EOF
)

echo "$BACKEND_BLOCK" | sudo tee -a $HAPROXY_CFG > /dev/null

echo "$AUTOCONFIG_END" | sudo tee -a $HAPROXY_CFG > /dev/null

echo "Config complete. restart haproxy."
sudo systemctl restart haproxy