#!/usr/bin/env bash
# Deploy Kadence on the server. Idempotent: run it for the first install and for
# every update after.
#
#   ssh sw_pl_1 '/opt/kadence/deploy/deploy.sh'
#
# What it does, skipping whatever is already true:
#   1. fetches the pinned branch from Gitea over SSH
#   2. makes sure .env exists and has the secrets that must not be defaults
#   3. installs the nginx vhost and gets a Let's Encrypt certificate
#   4. rebuilds and restarts the containers, then waits for /api/health
#
# It never writes .env values that are already set, so rotating a secret by hand
# survives the next deploy.
set -euo pipefail

REPO_DIR=${REPO_DIR:-/opt/kadence}
DOMAIN=${DOMAIN:-kadence.timka.su}
BRANCH=${BRANCH:-master}
BIND=${KADENCE_BIND:-127.0.0.1:8010}
COMPOSE=(docker compose -f docker-compose.yml -f docker-compose.prod.yml)

say() { printf '\n\033[1;36m==> %s\033[0m\n' "$*"; }
warn() { printf '\033[1;33m !! %s\033[0m\n' "$*"; }

cd "$REPO_DIR"

# ---- 1. code ---------------------------------------------------------------
# This script lives in the repo it updates, so `git reset --hard` rewrites the
# file bash is in the middle of reading. Bash reads a script incrementally and
# keeps a byte offset, so after the reset it resumes at that offset in the *new*
# file — silently skipping or garbling whatever the diff shifted. (That is not
# hypothetical: it is how the certbot renewal hook came to be committed, present
# on disk, and never executed.)
#
# So: stage one updates the checkout and re-execs a *copy* outside the repo,
# which nothing can rewrite underneath it. Stage two does the actual work.
if [[ ${KADENCE_DEPLOY_STAGE:-} != run ]]; then
    say "Fetching $BRANCH from $(git remote get-url origin)"
    git fetch --prune origin
    git checkout -q "$BRANCH"
    git reset --hard "origin/$BRANCH"
    echo "now at $(git log --oneline -1)"

    staged=$(mktemp /tmp/kadence-deploy.XXXXXX.sh)
    cat "$REPO_DIR/deploy/deploy.sh" > "$staged"
    chmod +x "$staged"
    export KADENCE_DEPLOY_STAGE=run KADENCE_DEPLOY_STAGED="$staged"
    exec "$staged" "$@"
fi

# Stage two: started from the copy, so clean it up on the way out.
trap '[[ -n ${KADENCE_DEPLOY_STAGED:-} ]] && rm -f "$KADENCE_DEPLOY_STAGED"' EXIT

# ---- 2. secrets ------------------------------------------------------------
setkv() {
    local key=$1 value=$2
    sed -i "/^${key}=/d" .env 2>/dev/null || true
    printf '%s=%s\n' "$key" "$value" >> .env
}

# `.env.example` ships placeholders rather than blanks — `POSTGRES_PASSWORD=change-me`
# is the dangerous one — so "already set" has to mean "set to something real", not
# merely "present".
is_placeholder() {
    case "$1" in
        ''|change-me|changeme|'*'|your-*|TODO) return 0 ;;
        *) return 1 ;;
    esac
}

# Generated once, then left alone: a deploy that silently rotated API_TOKEN would
# lock out the phone and the desktop app, so this only ever fills a blank.
ensure_secret() {
    local key=$1 value=$2
    local current
    current=$(sed -n "s/^${key}=//p" .env 2>/dev/null | tail -1)
    if ! is_placeholder "$current"; then
        return
    fi
    setkv "$key" "$value"
    echo "   generated $key"
}

if [[ ! -f .env ]]; then
    say "Creating .env from .env.example"
    cp .env.example .env
fi
chmod 600 .env

say "Checking secrets"
ensure_secret API_TOKEN         "$(openssl rand -hex 32)"
ensure_secret POSTGRES_PASSWORD "$(openssl rand -hex 24)"

# Deployment facts rather than secrets: these describe where this instance runs,
# so the script owns them outright and corrects them if they drift.
setkv KADENCE_BIND "$BIND"
setkv CORS_ORIGINS "https://${DOMAIN}"
setkv TIMEZONE     "${TIMEZONE:-Europe/Moscow}"

if ! grep -qE '^AUTH_PASSWORD=.+' .env; then
    warn "AUTH_PASSWORD is blank — the browser UI is open to anyone who finds the"
    warn "domain. Set it in .env and re-run, or run:"
    warn "   cd $REPO_DIR && ${COMPOSE[*]} exec app python -m app.cli set-password"
fi

# ---- 3. nginx + TLS --------------------------------------------------------
VHOST_SRC="deploy/nginx/${DOMAIN}.conf"
VHOST_DST="/etc/nginx/sites-available/${DOMAIN}"
CERT_DIR="/etc/letsencrypt/live/${DOMAIN}"

mkdir -p /var/www/certbot

if [[ ! -d $CERT_DIR ]]; then
    say "No certificate yet — serving the ACME challenge over plain HTTP first"
    # The repo vhost references a cert that does not exist, so nginx would refuse
    # to load it. Stand up an HTTP-only vhost just long enough to be validated.
    cat > "$VHOST_DST" <<EOF
server {
    listen 80;
    listen [::]:80;
    server_name ${DOMAIN};
    location /.well-known/acme-challenge/ { root /var/www/certbot; }
    location / { return 503; }
}
EOF
    ln -sfn "$VHOST_DST" "/etc/nginx/sites-enabled/${DOMAIN}"
    nginx -t && systemctl reload nginx

    say "Requesting a certificate for ${DOMAIN}"
    # `certonly --webroot`, not `--nginx`: the vhost is managed in git and
    # certbot's nginx installer would rewrite it behind our back.
    certbot certonly --webroot -w /var/www/certbot -d "$DOMAIN" \
        --non-interactive --agree-tos --register-unsafely-without-email \
        --keep-until-expiring
fi

# `certonly` renews the files but tells nothing to pick them up, so without a
# deploy hook nginx keeps serving the old certificate until something reloads it
# by chance — i.e. it silently expires. `--nginx` would have done this for us;
# this is the price of keeping the vhost in git.
say "Installing the renewal hook"
install -d /etc/letsencrypt/renewal-hooks/deploy
cat > /etc/letsencrypt/renewal-hooks/deploy/reload-nginx.sh <<'HOOK'
#!/bin/sh
# Installed by kadence's deploy/deploy.sh. Runs after any successful renewal.
nginx -t && systemctl reload nginx
HOOK
chmod 755 /etc/letsencrypt/renewal-hooks/deploy/reload-nginx.sh

say "Installing the vhost"
install -m 644 "$VHOST_SRC" "$VHOST_DST"
ln -sfn "$VHOST_DST" "/etc/nginx/sites-enabled/${DOMAIN}"
nginx -t
systemctl reload nginx

# ---- 4. containers ---------------------------------------------------------
say "Building and starting"
"${COMPOSE[@]}" up -d --build

say "Waiting for the API"
for attempt in $(seq 1 60); do
    if curl -fsS "http://${BIND}/api/health" >/dev/null 2>&1; then
        echo "   healthy after ${attempt}s"
        break
    fi
    if [[ $attempt == 60 ]]; then
        warn "still not healthy; last 40 lines of the app log:"
        "${COMPOSE[@]}" logs --tail 40 app
        exit 1
    fi
    sleep 1
done

say "Done"
curl -fsS "https://${DOMAIN}/api/health" && echo
curl -fsS "https://${DOMAIN}/api/info" && echo