#!/bin/bash
set -euo pipefail

ROOT=$(CDPATH='' cd -- "$(dirname -- "$0")/.." && pwd)
env_file=${1:-}
expected_domain=${2:-}

usage() {
  echo "Usage: $0 ENV_FILE EXPECTED_DOMAIN" >&2
}

if [[ -z "$env_file" || -z "$expected_domain" ]]; then
  usage
  exit 1
fi

if [[ ! -f "$env_file" ]]; then
  echo "Deployment environment does not exist: $env_file" >&2
  exit 1
fi

if [[ "$(stat -c '%a' "$env_file")" != 600 ]]; then
  echo "Deployment environment must have mode 0600: $env_file" >&2
  exit 1
fi

if [[ "$(stat -c '%u' "$env_file")" != "$(id -u)" ]]; then
  echo "Deployment environment must be owned by the current operator." >&2
  exit 1
fi

read_value() {
  local key=$1

  awk -v key="$key" '
    index($0, key "=") == 1 {
      print substr($0, length(key) + 2)
      found = 1
    }
    END { if (!found) exit 1 }
  ' "$env_file"
}

require_value() {
  local key=$1
  local value

  if ! value=$(read_value "$key") || [[ -z "$value" ]]; then
    echo "$key is missing or empty in $env_file." >&2
    exit 1
  fi

  printf '%s' "$value"
}

reject_marker() {
  local key=$1
  local value=$2

  case "$value" in
    *REPLACE* | *GENERATE* | *example.com*)
      echo "$key still contains a template value." >&2
      exit 1
      ;;
  esac
}

phx_host=$(require_value PHX_HOST)
phx_scheme=$(require_value PHX_SCHEME)
phx_url_port=$(require_value PHX_URL_PORT)
base_url=$(require_value WNH_BASE_URL)
debug_base_url=$(require_value WNH_DEBUG_BASE_URL)
http_bind_address=$(require_value HTTP_BIND_ADDRESS)
trusted_proxy_ips=$(require_value TRAEFIK_TRUSTED_IPS)
postgres_password=$(require_value POSTGRES_PASSWORD)
database_url=$(require_value DATABASE_URL)
secret_key_base=$(require_value SECRET_KEY_BASE)
handover_secret=$(require_value HANDOVER_SECRET)
release_cookie=$(require_value RELEASE_COOKIE)
metrics_token=$(require_value METRICS_TOKEN)
smtp_relay=$(require_value SMTP_RELAY)
smtp_port=$(require_value SMTP_PORT)
smtp_auth=$(require_value SMTP_AUTH)
smtp_tls=$(require_value SMTP_TLS)
smtp_ssl=$(require_value SMTP_SSL)
email_from_address=$(require_value EMAIL_FROM_ADDRESS)

[[ "$phx_host" == "$expected_domain" ]] || {
  echo "PHX_HOST does not match EXPECTED_DOMAIN." >&2
  exit 1
}
[[ "$phx_scheme" == https && "$phx_url_port" == 443 ]] || {
  echo "Production PHX_SCHEME/PHX_URL_PORT must describe the public HTTPS origin." >&2
  exit 1
}
[[ "$base_url" == "https://$expected_domain" ]] || {
  echo "WNH_BASE_URL does not match the public HTTPS origin." >&2
  exit 1
}
[[ "$debug_base_url" == "$base_url" ]] || {
  echo "WNH_DEBUG_BASE_URL and WNH_BASE_URL must use the same deployment origin." >&2
  exit 1
}

for pair in \
  "HTTP_BIND_ADDRESS:$http_bind_address" \
  "TRAEFIK_TRUSTED_IPS:$trusted_proxy_ips" \
  "POSTGRES_PASSWORD:$postgres_password" \
  "DATABASE_URL:$database_url" \
  "SECRET_KEY_BASE:$secret_key_base" \
  "HANDOVER_SECRET:$handover_secret" \
  "RELEASE_COOKIE:$release_cookie" \
  "METRICS_TOKEN:$metrics_token" \
  "SMTP_RELAY:$smtp_relay" \
  "EMAIL_FROM_ADDRESS:$email_from_address"
do
  reject_marker "${pair%%:*}" "${pair#*:}"
done

[[ "$smtp_relay" != mailpit ]] || {
  echo "SMTP_RELAY still targets local Mailpit; public registration needs a transactional relay." >&2
  exit 1
}
[[ "$smtp_port" =~ ^[0-9]+$ ]] || {
  echo "SMTP_PORT must be numeric." >&2
  exit 1
}
[[ "$smtp_auth" =~ ^(always|never|if_available)$ ]] || {
  echo "SMTP_AUTH has an unsupported value." >&2
  exit 1
}
[[ "$smtp_tls" =~ ^(always|never|if_available)$ ]] || {
  echo "SMTP_TLS has an unsupported value." >&2
  exit 1
}
[[ "$smtp_ssl" =~ ^(true|false|0|1)$ ]] || {
  echo "SMTP_SSL has an unsupported value." >&2
  exit 1
}
[[ "$email_from_address" == *@* ]] || {
  echo "EMAIL_FROM_ADDRESS is not an email address." >&2
  exit 1
}

secrets=(
  "$postgres_password"
  "$secret_key_base"
  "$handover_secret"
  "$release_cookie"
  "$metrics_token"
)

for ((left = 0; left < ${#secrets[@]}; left++)); do
  for ((right = left + 1; right < ${#secrets[@]}; right++)); do
    if [[ "${secrets[$left]}" == "${secrets[$right]}" ]]; then
      echo "Deployment secrets must be independent." >&2
      exit 1
    fi
  done
done

expected_database_url="ecto://postgres:$postgres_password@db/who_need_help"
[[ "$database_url" == "$expected_database_url" ]] || {
  echo "DATABASE_URL does not match the generated PostgreSQL role/password/database." >&2
  exit 1
}

docker compose \
  --env-file "$env_file" \
  --file "$ROOT/compose.yaml" \
  --file "$ROOT/compose.production.yaml" \
  config --quiet

echo "Production environment structure passed validation without printing secrets."
echo "This does not test DNS, TLS, SMTP reachability/delivery, proxy source IPs, or server capacity."