#!/bin/bash
#
# Boot Update Script: pull latest main, install, build, and prepare for PM2.
# Runs on LXC container boot BEFORE PM2 starts (my-weekly-todo-update.service).
#
# The whole body is wrapped in a function so bash parses it in one go: this script lives
# inside the very checkout it updates, and `git pull` rewriting it mid-run would otherwise
# make bash resume at a stale file offset.

main() {
    # pipefail matters here: every command used to be piped into `tee`, so the shell saw
    # tee's exit status (always 0). A failed npm install or build did not stop the script
    # and did not fail the unit — it just logged "finished" and left a half-built tree.
    set -euo pipefail

    local APP_DIR="/root/My-Weekly-ToDo-List"
    local LOG_FILE="/var/log/app-boot-update.log"

    # Send everything to the log once, instead of piping each command through tee.
    exec > >(tee -a "$LOG_FILE") 2>&1

    log() { echo "[$(date '+%Y-%m-%d %H:%M:%S')] $1"; }

    trap 'log "!!! Boot update FAILED at line $LINENO (exit $?) — not restarting the app"' ERR

    # Fail fast instead of hanging on a credential prompt when run without a terminal
    # (systemd has no tty). The host authenticates via a read-only SSH deploy key.
    export GIT_TERMINAL_PROMPT=0

    log "=== Boot update started ==="

    cd "$APP_DIR"

    log "Ensuring main branch..."
    git checkout main

    log "Fetching from origin..."
    git fetch origin main

    local LOCAL REMOTE NEXT_DIR
    LOCAL=$(git rev-parse HEAD)
    REMOTE=$(git rev-parse origin/main)
    NEXT_DIR="$APP_DIR/.next"

    if [ "$LOCAL" = "$REMOTE" ] && [ -d "$NEXT_DIR" ]; then
        log "Already up-to-date and .next exists. No rebuild needed."
        log "=== Boot update finished (no changes) ==="
        return 0
    fi

    if [ "$LOCAL" != "$REMOTE" ]; then
        log "Changes detected. Updating from $LOCAL to $REMOTE"
        git pull origin main

        # npm ci, not npm install: it installs exactly what package-lock.json specifies and
        # never rewrites it. npm install rewrites the lockfile, which leaves the working
        # tree dirty and makes the *next* git pull abort. npm ci also clears node_modules
        # itself; if that ever fails with ENOTEMPTY, delete the directory by hand and rerun.
        log "Installing dependencies..."
        npm ci
    fi

    if [ ! -d "$NEXT_DIR" ] || [ "$LOCAL" != "$REMOTE" ]; then
        log "Updating database schema (safe migrate)..."
        npx prisma migrate deploy || {
            log "migrate deploy failed, falling back to db push..."
            npx prisma db push --accept-data-loss
        }

        log "Regenerating Prisma client..."
        npx prisma generate

        log "Building application..."
        npm run build

        # next.config.js sets output: 'standalone', and Next.js does NOT copy public/ or
        # .next/static/ into .next/standalone — that is a documented manual step. Skipping
        # it ships new server code whose HTML references new chunk hashes while the old
        # chunks sit in the standalone tree: they 404, React never hydrates, and every page
        # hangs on "Loading session..." while the API still answers 200.
        log "Preparing standalone directory (static assets and env)..."
        cp -r public .next/standalone/
        mkdir -p .next/standalone/.next/static
        cp -r .next/static .next/standalone/.next/
        cp .env .next/standalone/ 2>/dev/null || true
    fi

    log "Deployed version: $(node -p "require('$APP_DIR/package.json').version")"
    log "=== Boot update finished (verified/rebuilt) ==="
}

main "$@"