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

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

if [[ "$env_file" != /* ]]; then
  env_file="$ROOT/$env_file"
fi

if [[ "$mode" != "" && "$mode" != "--require-release" ]]; then
  echo "Usage: $0 [ENV_FILE] [--require-release]" >&2
  exit 2
fi

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

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

read_value() {
  local key=$1

  awk -v key="$key" '
    index($0, key "=") == 1 {
      value = substr($0, length(key) + 2)
      if (value ~ /^".*"$/ || value ~ /^'\''.*'\''$/) {
        value = substr(value, 2, length(value) - 2)
      }
      print value
      found = 1
      exit
    }
    END { if (!found) exit 1 }
  ' "$env_file"
}

value() {
  read_value "$1" 2>/dev/null || true
}

is_set() {
  [[ -n "$(value "$1")" ]]
}

all_set() {
  local key
  for key in "$@"; do
    is_set "$key" || return 1
  done
}

all_empty() {
  local key
  for key in "$@"; do
    is_set "$key" && return 1
  done
  return 0
}

contains_template_marker() {
  local observed=$1
  [[ "$observed" == *REPLACE* || "$observed" == *GENERATE* ||
    "$observed" == *example.com* || "$observed" == *example.invalid* ]]
}

valid_fcm_service_account_json() {
  jq -e '
    .type == "service_account" and
    (.project_id | type == "string" and length > 0) and
    (.client_email | type == "string" and length > 0) and
    (.private_key | type == "string" and length > 0)
  ' >/dev/null 2>&1
}

fcm_service_account_project_id() {
  jq -er '
    select(
      .type == "service_account" and
      (.project_id | type == "string" and length > 0) and
      (.client_email | type == "string" and length > 0) and
      (.private_key | type == "string" and length > 0)
    )
    | .project_id
  ' 2>/dev/null
}

firebase_client_values_valid() {
  local application_id sender_id prefix

  application_id=$(value WNH_FIREBASE_APPLICATION_ID)
  sender_id=$(value WNH_FIREBASE_GCM_SENDER_ID)
  prefix="1:$sender_id:android:"

  [[ "$sender_id" =~ ^[0-9]+$ &&
    "$application_id" == "$prefix"* &&
    -n "${application_id#"$prefix"}" ]]
}

valid_sha256_fingerprint_list() {
  local fingerprint compact
  local -a fingerprint_list

  IFS=',' read -r -a fingerprint_list <<<"$1"
  [[ ${#fingerprint_list[@]} -gt 0 ]] || return 1

  for fingerprint in "${fingerprint_list[@]}"; do
    compact=${fingerprint//:/}
    compact=${compact//[[:space:]]/}
    [[ "$compact" =~ ^[0-9A-Fa-f]{64}$ ]] || return 1
  done
}

failures=0
warnings=0

ready() {
  printf 'READY      %-24s %s\n' "$1" "$2"
}

local_only() {
  printf 'LOCAL_ONLY %-24s %s\n' "$1" "$2"
  warnings=$((warnings + 1))
}

missing() {
  printf 'MISSING    %-24s %s\n' "$1" "$2"
  failures=$((failures + 1))
}

invalid() {
  printf 'INVALID    %-24s %s\n' "$1" "$2"
  failures=$((failures + 1))
}

partial() {
  printf 'PARTIAL    %-24s %s\n' "$1" "$2"
  failures=$((failures + 1))
}

deployment_env=$(value DEPLOYMENT_ENV)
phx_host=$(value PHX_HOST)
phx_scheme=$(value PHX_SCHEME)
phx_port=$(value PHX_URL_PORT)
base_url=$(value WNH_BASE_URL)
debug_base_url=$(value WNH_DEBUG_BASE_URL)

if all_set DEPLOYMENT_ENV PHX_HOST PHX_SCHEME PHX_URL_PORT WNH_BASE_URL WNH_DEBUG_BASE_URL &&
  [[ "$base_url" == "$debug_base_url" ]] &&
  [[ "$base_url" == "$phx_scheme://$phx_host" ||
    "$base_url" == "$phx_scheme://$phx_host:$phx_port" ]] &&
  ! contains_template_marker "$base_url"; then
  ready "public origin" "deployment=$deployment_env; one canonical Android/web origin"
else
  invalid "public origin" "DEPLOYMENT_ENV/PHX_*/WNH_*_BASE_URL are incomplete or inconsistent"
fi

if all_set SECRET_KEY_BASE HANDOVER_SECRET RELEASE_COOKIE METRICS_TOKEN; then
  ready "application secrets" "four required independent values are present"
else
  missing "application secrets" "SECRET_KEY_BASE, HANDOVER_SECRET, RELEASE_COOKIE, METRICS_TOKEN"
fi

smtp_relay=$(value SMTP_RELAY)
email_delivery_provider=$(value EMAIL_DELIVERY_PROVIDER)
email_delivery_provider=${email_delivery_provider:-smtp}
if [[ "$email_delivery_provider" != "smtp" ]]; then
  invalid "transactional email" "EMAIL_DELIVERY_PROVIDER must be smtp"
elif ! all_set SMTP_RELAY SMTP_PORT SMTP_AUTH SMTP_TLS SMTP_SSL EMAIL_FROM_ADDRESS; then
  missing "transactional email" "SMTP transport and sender fields"
elif [[ "$smtp_relay" == "mailpit" ]]; then
  local_only "transactional email" "Mailpit captures messages locally; it cannot deliver public email"
elif [[ "$(value SMTP_AUTH)" == "always" ]] && ! all_set SMTP_USERNAME SMTP_PASSWORD; then
  partial "transactional email" "authenticated SMTP requires both username and password"
else
  ready "transactional email" "external SMTP transport is configured"
fi

if is_set SUPPORT_INBOX_ADDRESS; then
  ready "support inbox" "operator destination is configured"
else
  missing "support inbox" "SUPPORT_INBOX_ADDRESS"
fi

if all_empty GOOGLE_OAUTH_CLIENT_ID GOOGLE_OAUTH_CLIENT_SECRET; then
  missing "Google sign-in" "GOOGLE_OAUTH_CLIENT_ID and GOOGLE_OAUTH_CLIENT_SECRET"
elif all_set GOOGLE_OAUTH_CLIENT_ID GOOGLE_OAUTH_CLIENT_SECRET; then
  ready "Google sign-in" "client ID and secret are both configured"
else
  partial "Google sign-in" "client ID and secret must be configured together"
fi

if all_empty WEB_PUSH_VAPID_PUBLIC_KEY WEB_PUSH_VAPID_PRIVATE_KEY WEB_PUSH_VAPID_SUBJECT; then
  missing "browser Web Push" "VAPID public/private keys and subject"
elif all_set WEB_PUSH_VAPID_PUBLIC_KEY WEB_PUSH_VAPID_PRIVATE_KEY WEB_PUSH_VAPID_SUBJECT; then
  case "$(value WEB_PUSH_VAPID_SUBJECT)" in
    mailto:* | https://*) ready "browser Web Push" "complete VAPID configuration" ;;
    *) invalid "browser Web Push" "WEB_PUSH_VAPID_SUBJECT must use mailto: or https://" ;;
  esac
else
  partial "browser Web Push" "all three VAPID values are required together"
fi

if all_empty WNH_FIREBASE_APPLICATION_ID WNH_FIREBASE_API_KEY \
  WNH_FIREBASE_PROJECT_ID WNH_FIREBASE_GCM_SENDER_ID; then
  missing "Android Firebase client" "four WNH_FIREBASE_* Android client values"
elif all_set WNH_FIREBASE_APPLICATION_ID WNH_FIREBASE_API_KEY \
  WNH_FIREBASE_PROJECT_ID WNH_FIREBASE_GCM_SENDER_ID; then
  if firebase_client_values_valid; then
    ready "Android Firebase client" "complete internally consistent client configuration"
  else
    invalid "Android Firebase client" \
      "application ID must belong to the numeric configured sender/project number"
  fi
else
  partial "Android Firebase client" "all four WNH_FIREBASE_* values are required together"
fi

fcm_file=$(value FCM_SERVICE_ACCOUNT_FILE)
fcm_base64=$(value FCM_SERVICE_ACCOUNT_JSON_BASE64)
fcm_project_id=$(value FCM_PROJECT_ID)
firebase_project_id=$(value WNH_FIREBASE_PROJECT_ID)
fcm_credential_project_id=
if [[ -z "$fcm_project_id" && -z "$fcm_file" && -z "$fcm_base64" ]]; then
  missing "Android FCM delivery" "FCM project ID and one service-account source"
elif [[ -z "$fcm_project_id" || (-n "$fcm_file" && -n "$fcm_base64") ||
  (-z "$fcm_file" && -z "$fcm_base64") ]]; then
  partial "Android FCM delivery" "project ID and exactly one credential source are required"
elif [[ -n "$fcm_file" ]]; then
  if [[ "$fcm_file" == /* && -r "$fcm_file" ]] &&
    fcm_credential_project_id=$(fcm_service_account_project_id <"$fcm_file") &&
    [[ "$fcm_credential_project_id" == "$fcm_project_id" ]] &&
    [[ -z "$firebase_project_id" || "$fcm_project_id" == "$firebase_project_id" ]]; then
    ready "Android FCM delivery" "service account and Android client use the same project"
  else
    invalid "Android FCM delivery" \
      "credential source and configured Firebase/FCM project IDs are incomplete or inconsistent"
  fi
elif fcm_credential_project_id=$(
  printf '%s' "$fcm_base64" |
    base64 --decode 2>/dev/null |
    fcm_service_account_project_id
) &&
  [[ "$fcm_credential_project_id" == "$fcm_project_id" ]] &&
  [[ -z "$firebase_project_id" || "$fcm_project_id" == "$firebase_project_id" ]]; then
  ready "Android FCM delivery" "service account and Android client use the same project"
else
  invalid "Android FCM delivery" \
    "credential source and configured Firebase/FCM project IDs are incomplete or inconsistent"
fi

expected_android_package=
case "$deployment_env" in
  development) expected_android_package=org.whoneedhelp.mobile.development ;;
  test) expected_android_package=org.whoneedhelp.mobile.staging ;;
  production) expected_android_package=org.whoneedhelp.mobile ;;
esac

if all_empty ANDROID_APP_LINKS_PACKAGE_NAME \
  ANDROID_APP_LINKS_SHA256_CERT_FINGERPRINTS \
  ANDROID_PLAY_APP_SIGNING_SHA256_CERT_FINGERPRINTS; then
  missing "Android App Links" "package name and signing certificate fingerprint"
elif all_set ANDROID_APP_LINKS_PACKAGE_NAME ANDROID_APP_LINKS_SHA256_CERT_FINGERPRINTS; then
  if [[ -z "$expected_android_package" ||
    "$(value ANDROID_APP_LINKS_PACKAGE_NAME)" != "$expected_android_package" ]]; then
    invalid "Android App Links" "package does not match DEPLOYMENT_ENV=$deployment_env"
  elif ! valid_sha256_fingerprint_list \
    "$(value ANDROID_APP_LINKS_SHA256_CERT_FINGERPRINTS)"; then
    invalid "Android App Links" "published signing fingerprints are malformed"
  elif [[ "$deployment_env" != production ]]; then
    ready "Android App Links" "package and signing fingerprints match this environment"
  elif ! is_set ANDROID_PLAY_APP_SIGNING_SHA256_CERT_FINGERPRINTS; then
    missing "Android App Links" "production requires the Play App Signing SHA-256 fingerprint"
  elif ! valid_sha256_fingerprint_list \
    "$(value ANDROID_PLAY_APP_SIGNING_SHA256_CERT_FINGERPRINTS)"; then
    invalid "Android App Links" "Play App Signing fingerprints are malformed"
  else
    published_fingerprints=$(value ANDROID_APP_LINKS_SHA256_CERT_FINGERPRINTS)
    play_fingerprints=$(value ANDROID_PLAY_APP_SIGNING_SHA256_CERT_FINGERPRINTS)
    all_play_fingerprints_published=true
    IFS=',' read -r -a play_fingerprint_list <<<"$play_fingerprints"
    IFS=',' read -r -a published_fingerprint_list <<<"$published_fingerprints"
    for play_fingerprint in "${play_fingerprint_list[@]}"; do
      compact_play=${play_fingerprint//:/}
      compact_play=${compact_play//[[:space:]]/}
      play_found=false
      for published_fingerprint in "${published_fingerprint_list[@]}"; do
        compact_published=${published_fingerprint//:/}
        compact_published=${compact_published//[[:space:]]/}
        if [[ "${compact_play^^}" == "${compact_published^^}" ]]; then
          play_found=true
          break
        fi
      done
      if [[ "$play_found" != true ]]; then
        all_play_fingerprints_published=false
        break
      fi
    done
    if [[ "$all_play_fingerprints_published" == true ]]; then
      ready "Android App Links" "published identities include the Play App Signing certificate"
    else
      invalid "Android App Links" "Play App Signing fingerprint is absent from the published identities"
    fi
  fi
else
  partial "Android App Links" "package and signing fingerprints are incomplete"
fi

android_signing_alias=
android_signing_label=
case "$deployment_env" in
  development)
    android_signing_alias=WNH_ANDROID_DEVELOPMENT_SIGNING_KEY_ALIAS
    android_signing_label=development
    ;;
  test)
    android_signing_alias=WNH_ANDROID_STAGING_SIGNING_KEY_ALIAS
    android_signing_label=staging
    ;;
  production)
    android_signing_alias=WNH_ANDROID_SIGNING_KEY_ALIAS
    android_signing_label=production
    ;;
esac

if [[ -n "$android_signing_alias" ]] &&
  all_set WNH_ANDROID_VERSION_CODE WNH_ANDROID_VERSION_NAME "$android_signing_alias"; then
  ready "Android release inputs" \
    "version and $android_signing_label signing alias are present"
else
  missing "Android release inputs" \
    "version code/name and the signing alias for DEPLOYMENT_ENV=$deployment_env"
fi

printf '\nEnvironment readiness: %d blocking item(s), %d local-only warning(s).\n' \
  "$failures" "$warnings"

if [[ "$mode" == "--require-release" && ($failures -ne 0 || $warnings -ne 0) ]]; then
  exit 1
fi