#!/usr/bin/env bash
# Roll back the ambrosio production stack to a previously-deployed commit.
#
# Usage:
#   infra/scripts/rollback-erosi.sh --list             # print recent deploys
#   infra/scripts/rollback-erosi.sh --previous         # roll back to N-1
#   infra/scripts/rollback-erosi.sh --to=<git-sha>     # roll back to a specific deploy
#   infra/scripts/rollback-erosi.sh --code-only --to=<sha>   # skip DB restore
#
# Env:
#   DEPLOY_HOST=ambrosio (override if needed)
#   DEPLOY_PATH=/opt/colectivo
#
# How it works:
#   The deploy script (deploy-erosi.sh) writes one line per successful
#   deploy to /opt/colectivo/.deploys.log:
#       <iso-ts>  <git-sha>  <backup-file>
#   Rollback reads that log, picks the row matching --previous or --to,
#   then:
#     1. Verifies the SHA is reachable in the local git repo.
#     2. Verifies the matching backup file still exists on ambrosio.
#     3. Asks for explicit confirmation (destructive op).
#     4. Checks out that SHA into a temp worktree on this machine.
#     5. rsync (excluding .git, etc.) → ambrosio.
#     6. Restores the DB from the matched backup.
#     7. Rebuilds the app image at the rollback SHA and brings the stack
#        up. NOTE: --code-only skips step 6.
#     8. Cleans up the worktree. Does NOT write a new line to
#        .deploys.log — rollback is intentionally not deploy-equivalent.
#
# What is NOT rolled back:
#   * Storage volume (/var/lib/storage) — user uploads. Treated as
#     append-only; backup taken pre-deploy but never restored on rollback.
#   * Realtime tenant state, Kong runtime config. They are stateless or
#     re-bootstrap from the DB.

set -euo pipefail

DEPLOY_HOST="${DEPLOY_HOST:-ambrosio}"
DEPLOY_PATH="${DEPLOY_PATH:-/opt/colectivo}"
REPO_ROOT="$(cd "$(dirname "$0")/../.." && pwd)"

MODE=""
TARGET_SHA=""
CODE_ONLY=0

while [ $# -gt 0 ]; do
	case "$1" in
		--list)        MODE="list" ;;
		--previous)    MODE="previous" ;;
		--to=*)        MODE="to"; TARGET_SHA="${1#--to=}" ;;
		--code-only)   CODE_ONLY=1 ;;
		-h|--help)
			grep '^#' "$0" | sed 's/^# \{0,1\}//' | head -40
			exit 0
			;;
		*) echo "Unknown arg: $1" >&2; exit 1 ;;
	esac
	shift
done

[ -z "$MODE" ] && { echo "Specify --list, --previous, or --to=<sha>." >&2; exit 1; }

# ── 1. Read deploy log from ambrosio ──────────────────────────────────────
log=$(ssh "$DEPLOY_HOST" "cat $DEPLOY_PATH/.deploys.log 2>/dev/null || true")
if [ -z "$log" ]; then
	echo "No deploy history found at $DEPLOY_HOST:$DEPLOY_PATH/.deploys.log" >&2
	exit 1
fi

if [ "$MODE" = "list" ]; then
	echo "Recent deploys ($DEPLOY_HOST):"
	echo "------------------------------------------------------------"
	# Fase 17.3.3 — re-format each row so the tag (column 4, optional)
	# is visible at a glance. Rows from before Fase 17 only have 3
	# columns; the 4th `cut` returns empty and we substitute "(no tag)".
	# Falls back to the raw log if awk isn't present (it always is on
	# the deploy host, but we want the script to be robust on any
	# operator laptop).
	if command -v awk >/dev/null 2>&1; then
		printf '%s\n' "$log" \
			| awk -F '\t' '{ tag = ($4 == "" ? "(no tag)" : $4); printf "%s\t%s\t%s\t%s\n", $1, $2, tag, $3 }' \
			| nl -ba
	else
		printf '%s\n' "$log" | nl -ba
	fi
	exit 0
fi

# ── 2. Pick the target row ────────────────────────────────────────────────
if [ "$MODE" = "previous" ]; then
	# Last line = current deploy. Second-to-last = previous.
	target_row=$(printf '%s\n' "$log" | tail -n 2 | head -n 1)
elif [ "$MODE" = "to" ]; then
	target_row=$(printf '%s\n' "$log" | grep -F "	$TARGET_SHA	" | tail -n 1 || true)
fi

if [ -z "${target_row:-}" ]; then
	echo "No matching deploy found." >&2
	exit 1
fi

target_ts=$(printf '%s' "$target_row" | cut -f1)
target_sha=$(printf '%s' "$target_row" | cut -f2)
target_backup=$(printf '%s' "$target_row" | cut -f3)
# Fase 17.3.3 — 4th column is the tag (optional, empty on pre-Fase-17 rows).
target_tag=$(printf '%s' "$target_row" | cut -f4)

echo "==> Rollback target"
echo "    timestamp: $target_ts"
echo "    git sha:   $target_sha"
if [ -n "${target_tag:-}" ]; then
	echo "    git tag:   $target_tag"
fi
echo "    backup:    $target_backup"

# ── 3. Verify SHA + backup ───────────────────────────────────────────────
if ! git -C "$REPO_ROOT" cat-file -e "${target_sha}^{commit}" 2>/dev/null; then
	echo "ERROR: commit $target_sha not present in local repo. Fetch first." >&2
	exit 1
fi

if [ "$CODE_ONLY" -eq 0 ]; then
	if ! ssh "$DEPLOY_HOST" "test -f $DEPLOY_PATH/$target_backup"; then
		echo "ERROR: backup $target_backup missing on $DEPLOY_HOST." >&2
		echo "       Use --code-only to skip the DB restore." >&2
		exit 1
	fi
fi

# ── 4. Confirm ────────────────────────────────────────────────────────────
echo ""
echo "WARNING: This is DESTRUCTIVE."
if [ "$CODE_ONLY" -eq 1 ]; then
	echo "         Code will be rolled back to $target_sha; DB is NOT touched."
else
	echo "         Code AND database will be rolled back."
	echo "         Current DB state will be overwritten by $target_backup."
fi
echo "         5s window to abort (Ctrl-C)..."
sleep 5

# ── 5. Worktree at the target SHA ────────────────────────────────────────
worktree_dir=$(mktemp -d -t colectivo-rollback-XXXXXX)
trap 'git -C "$REPO_ROOT" worktree remove --force "$worktree_dir" 2>/dev/null || rm -rf "$worktree_dir"' EXIT

echo "--- Materialising worktree at $target_sha → $worktree_dir"
git -C "$REPO_ROOT" worktree add --detach "$worktree_dir" "$target_sha" >/dev/null

# ── 6. rsync worktree → ambrosio ─────────────────────────────────────────
echo "--- rsync code to $DEPLOY_HOST:$DEPLOY_PATH"
rsync -az --delete \
	--exclude '.git' \
	--exclude 'node_modules' \
	--exclude '.svelte-kit' \
	--exclude 'apps/web/build' \
	--exclude 'apps/web/.vite' \
	--exclude '**/*.log' \
	--exclude '**/.env' \
	--exclude '**/.env.development' \
	--exclude '**/.env.local' \
	--exclude 'backups' \
	--exclude '.deploys.log' \
	"$worktree_dir/" "$DEPLOY_HOST:$DEPLOY_PATH/"

# ── 7. Restore DB (unless --code-only) ───────────────────────────────────
if [ "$CODE_ONLY" -eq 0 ]; then
	echo "--- Stopping app + auth + rest before DB restore"
	ssh "$DEPLOY_HOST" bash -s << REMOTE
set -euo pipefail
cd $DEPLOY_PATH
docker compose --env-file .env -f infra/docker-compose.erosi.yml stop app auth rest realtime storage
REMOTE

	echo "--- Restoring DB from $target_backup"
	ssh "$DEPLOY_HOST" bash -s << REMOTE
set -euo pipefail
cd $DEPLOY_PATH
gunzip -c $target_backup \
	| docker compose --env-file .env -f infra/docker-compose.erosi.yml exec -T db \
		psql -U postgres -d postgres -v ON_ERROR_STOP=1
REMOTE
fi

# ── 8. Rebuild + bring the stack back up at the rollback SHA ────────────
echo "--- Rebuild app at $target_sha + bring stack up"
ssh "$DEPLOY_HOST" env GIT_SHA="$target_sha" bash -s << 'REMOTE'
set -euo pipefail
cd /opt/colectivo
: "${GIT_SHA:=dev}"

GIT_SHA="$GIT_SHA" docker compose --env-file .env -f infra/docker-compose.erosi.yml \
	build --build-arg GIT_SHA="$GIT_SHA" app
GIT_SHA="$GIT_SHA" docker compose --env-file .env -f infra/docker-compose.erosi.yml up -d

# Reload PostgREST schema cache so any RPCs that changed shape between
# the rolled-back schema and the current rest container snapshot are
# resolved. Mirrors the same step at the end of deploy-erosi.sh.
docker compose --env-file .env -f infra/docker-compose.erosi.yml exec -T db \
	psql -U postgres -d postgres </dev/null \
	-c "NOTIFY pgrst, 'reload schema';"
REMOTE

echo ""
echo "==> Rollback complete."
echo "    code:  $target_sha"
if [ "$CODE_ONLY" -eq 1 ]; then
	echo "    db:    UNCHANGED (--code-only)"
else
	echo "    db:    restored from $target_backup"
fi
echo "    App:   https://erosi.limonia.net"
echo ""
echo "NOTE: .deploys.log is intentionally not updated by rollback."
echo "      The next 'just deploy' will be from your current HEAD."