#!/usr/bin/env bash
set -euo pipefail

REPO_ROOT="$(cd "$(dirname "$0")/.." && pwd)"
STATE_DIR="$REPO_ROOT/state/stacks"
VAULT_ADDR="${VAULT_ADDR:-https://vault.viktorbarzin.me}"

cmd="${1:-help}"
stack="${2:-}"  # optional: operate on single stack

# Check if Vault token is valid
vault_available() {
  VAULT_ADDR="$VAULT_ADDR" vault token lookup &>/dev/null 2>&1
}

# Per-stack Transit key URI
transit_uri() {
  local stack_name="$1"
  echo "${VAULT_ADDR}/v1/transit/keys/sops-state-${stack_name}"
}

# Extract stack name from directory path
stack_name_from_dir() {
  basename "$1"
}

# Read age recipients from .sops.yaml
AGE_RECIPIENTS="$(python3 -c "
import yaml, sys
with open('$REPO_ROOT/.sops.yaml') as f: c = yaml.safe_load(f)
for r in c.get('creation_rules', []):
    age = r.get('age', '')
    if age:
        print(age.replace('\n', '').strip())
        break
" 2>/dev/null || echo "")"

encrypt_state() {
  local dir="$1"
  local src="$dir/terraform.tfstate"
  local dst="$dir/terraform.tfstate.enc"
  local name
  name="$(stack_name_from_dir "$dir")"
  [ -f "$src" ] || return 0
  # Only re-encrypt if state is newer than encrypted version
  if [ ! -f "$dst" ] || [ "$src" -nt "$dst" ]; then
    sops -e --input-type json --output-type json \
      --hc-vault-transit "$(transit_uri "$name")" \
      --age "$AGE_RECIPIENTS" \
      "$src" > "$dst"
  fi
}

decrypt_state() {
  local dir="$1"
  local src="$dir/terraform.tfstate.enc"
  local dst="$dir/terraform.tfstate"
  [ -f "$src" ] || return 0

  if vault_available; then
    # Vault Transit — per-stack key, no local key needed
    sops -d --input-type json --output-type json "$src" > "$dst"
  elif [ -f "${SOPS_AGE_KEY_FILE:-$HOME/.config/sops/age/keys.txt}" ]; then
    # Fallback: age key on disk (bootstrap / Vault down)
    echo "state-sync: Vault unavailable, falling back to age key" >&2
    SOPS_AGE_KEY_FILE="${SOPS_AGE_KEY_FILE:-$HOME/.config/sops/age/keys.txt}" \
      sops -d --input-type json --output-type json "$src" > "$dst"
  else
    echo "state-sync: ERROR — no Vault token and no age key at ~/.config/sops/age/keys.txt" >&2
    return 1
  fi
}

case "$cmd" in
  encrypt)
    if [ -n "$stack" ]; then
      encrypt_state "$STATE_DIR/$stack"
    else
      for dir in "$STATE_DIR"/*/; do
        encrypt_state "$dir"
      done
    fi
    ;;
  decrypt)
    if [ -n "$stack" ]; then
      decrypt_state "$STATE_DIR/$stack"
    else
      for dir in "$STATE_DIR"/*/; do
        decrypt_state "$dir"
      done
    fi
    ;;
  commit)
    # Encrypt all changed state, then git add + commit
    "$0" encrypt
    cd "$REPO_ROOT"
    git add state/stacks/*/terraform.tfstate.enc
    if ! git diff --cached --quiet; then
      git commit -m "state: update encrypted terraform state"
    fi
    ;;
  help)
    echo "Usage: state-sync {encrypt|decrypt|commit} [stack-name]"
    echo "Encrypt uses per-stack Vault Transit key (transit/keys/sops-state-<stack>)."
    echo "Decrypt uses Vault Transit if logged in, falls back to age key."
    ;;
esac