# ── Cloud SQL — PostgreSQL 15 ─────────────────────────────────────────────────
# Single instance in us-central1 for the accounts service.
# Cloud Run services connect via the built-in Cloud SQL Auth Proxy
# (no direct IP exposure, encrypted, IAM-authenticated).
#
# Sizing: db-g1-small (1 shared vCPU, 1.7 GB) for launch. Scale up to
# db-n1-standard-2 once traffic warrants it — zero-downtime restart.

resource "google_sql_database_instance" "main" {
  name             = "neuron-prod-pg15"
  database_version = "POSTGRES_15"
  region           = "us-central1"
  project          = var.project_id

  # Prevent accidental deletion via terraform destroy
  deletion_protection = true

  settings {
    tier              = "db-g1-small"
    availability_type = "ZONAL"  # Upgrade to REGIONAL (HA) once > 1k users

    backup_configuration {
      enabled                        = true
      point_in_time_recovery_enabled = true
      start_time                     = "03:00"  # 3am UTC — before backup window on Legion
      transaction_log_retention_days = 7
      backup_retention_settings {
        retained_backups = 14
      }
    }

    maintenance_window {
      day          = 7  # Sunday
      hour         = 4  # 4am UTC
      update_track = "stable"
    }

    ip_configuration {
      # No public IP — Cloud Run uses the Auth Proxy via private service connect
      # Flip ipv4_enabled=true + authorized_networks if you ever need direct access
      # for migrations/seeding from a bastion.
      ipv4_enabled    = true   # Required for Cloud Run Auth Proxy (until VPC SC configured)
      ssl_mode        = "ENCRYPTED_ONLY"
    }

    database_flags {
      name  = "max_connections"
      value = "100"  # Cloud Run can burst many instances; cap connections early
    }

    database_flags {
      name  = "log_min_duration_statement"
      value = "500"  # Log queries taking > 500ms
    }

    insights_config {
      query_insights_enabled  = true
      query_string_length     = 1024
      record_application_tags = true
      record_client_address   = false
    }
  }
}

# ── Databases ─────────────────────────────────────────────────────────────────

resource "google_sql_database" "accounts" {
  name     = "accounts"
  instance = google_sql_database_instance.main.name
  project  = var.project_id
}

# ── Users ─────────────────────────────────────────────────────────────────────
# Passwords are stored in Secret Manager. The accounts service reads them
# at runtime via the ACCOUNTS_DATABASE_URL secret.
# Cloud IAM DB users are the preferred path long-term (no password rotation);
# using password auth here for compatibility with pgx/stdlib.

resource "google_sql_user" "accounts" {
  name     = "accounts"
  instance = google_sql_database_instance.main.name
  project  = var.project_id
  password = random_password.accounts_db.result
}

resource "random_password" "accounts_db" {
  length  = 32
  special = true
}

# ── Secret Manager — Database URL ─────────────────────────────────────────────
# Stored as a full DSN so the app just reads one env var.
# Uses /cloudsql/ Unix socket path — Cloud Run Auth Proxy mounts it there.

resource "google_secret_manager_secret" "accounts_database_url" {
  secret_id = "accounts-database-url"
  project   = var.project_id

  replication {
    auto {}
  }
}

resource "google_secret_manager_secret_version" "accounts_database_url" {
  secret = google_secret_manager_secret.accounts_database_url.id
  secret_data = "host=/cloudsql/${google_sql_database_instance.main.connection_name} user=accounts password=${random_password.accounts_db.result} dbname=accounts sslmode=disable"
}

# ── Secret Manager — JWT signing key ─────────────────────────────────────────
# Shared between accounts (issues tokens) and neuron-rest (validates tokens).

resource "random_password" "jwt_secret" {
  length  = 64
  special = false  # URL-safe; used as HMAC key
}

resource "google_secret_manager_secret" "jwt_secret" {
  secret_id = "jwt-signing-key"
  project   = var.project_id

  replication {
    auto {}
  }
}

resource "google_secret_manager_secret_version" "jwt_secret" {
  secret      = google_secret_manager_secret.jwt_secret.id
  secret_data = random_password.jwt_secret.result
}

# ── Secret Manager — License admin token ─────────────────────────────────────
# Used by neuron-rest to authorize license validation calls.
# Currently held in Vault under neuron-technologies/marketing.license_admin_token.
# Create this secret manually from Vault:
#   gcloud secrets create license-admin-token --data-file=<(vault kv get \
#     -field=license_admin_token secret/neuron-technologies/marketing)

resource "google_secret_manager_secret" "license_admin_token" {
  secret_id = "license-admin-token"
  project   = var.project_id

  replication {
    auto {}
  }
  # Version populated manually or via bootstrap script — not managed by Terraform
  # to avoid exposing the value in state.
  lifecycle {
    ignore_changes = [id]
  }
}

# ── Gitea — database + user on neuron-prod-pg15 ───────────────────────────────
# Gitea on GKE uses the existing Cloud SQL instance with a Cloud SQL Auth Proxy
# sidecar. Connection via unix socket — no public IP exposure.

resource "google_sql_database" "gitea" {
  name     = "gitea"
  instance = google_sql_database_instance.main.name
  project  = var.project_id
}

resource "random_password" "gitea_db" {
  length  = 32
  special = false # Cloud SQL unix socket path DSN; keep alphanumeric for simplicity
}

resource "google_sql_user" "gitea" {
  name     = "gitea"
  instance = google_sql_database_instance.main.name
  project  = var.project_id
  password = random_password.gitea_db.result
}

# ── Gitea service account (for Workload Identity → Cloud SQL) ─────────────────

resource "google_service_account" "gitea" {
  account_id   = "gitea-gke"
  display_name = "Gitea GKE SA"
  description  = "Service account for the Gitea pod on GKE. Used by the Cloud SQL Auth Proxy sidecar via Workload Identity."
  project      = var.project_id
}

resource "google_project_iam_member" "gitea_sql_client" {
  project = var.project_id
  role    = "roles/cloudsql.client"
  member  = "serviceAccount:${google_service_account.gitea.email}"
}

# ── Secret Manager — Gitea database URL ───────────────────────────────────────
# Full DSN using the Cloud SQL Auth Proxy unix socket path.
# The proxy sidecar mounts the socket at /cloudsql/<connection_name>.

resource "google_secret_manager_secret" "gitea_database_url" {
  secret_id = "gitea-database-url"
  project   = var.project_id

  replication {
    auto {}
  }
}

resource "google_secret_manager_secret_version" "gitea_database_url" {
  secret      = google_secret_manager_secret.gitea_database_url.id
  secret_data = "host=/cloudsql/${google_sql_database_instance.main.connection_name} user=gitea password=${random_password.gitea_db.result} dbname=gitea sslmode=disable"
}

# gitea-db-password — the raw password only, for use in Gitea's GITEA__database__PASSWD.
# The Cloud SQL Auth Proxy provides the unix socket; Gitea uses standard postgres
# password auth through the proxy socket.
resource "google_secret_manager_secret" "gitea_db_password" {
  secret_id = "gitea-db-password"
  project   = var.project_id

  replication {
    auto {}
  }
}

resource "google_secret_manager_secret_version" "gitea_db_password" {
  secret      = google_secret_manager_secret.gitea_db_password.id
  secret_data = random_password.gitea_db.result
}

# Allow the Gitea GCP SA to access its secrets
resource "google_secret_manager_secret_iam_member" "gitea_database_url_accessor" {
  project   = var.project_id
  secret_id = google_secret_manager_secret.gitea_database_url.secret_id
  role      = "roles/secretmanager.secretAccessor"
  member    = "serviceAccount:${google_service_account.gitea.email}"
}

resource "google_secret_manager_secret_iam_member" "gitea_db_password_accessor" {
  project   = var.project_id
  secret_id = google_secret_manager_secret.gitea_db_password.secret_id
  role      = "roles/secretmanager.secretAccessor"
  member    = "serviceAccount:${google_service_account.gitea.email}"
}

# ESO Workload Identity — allows the external-secrets controller SA on GKE
# to impersonate the gitea GCP SA for Secret Manager access.
resource "google_service_account_iam_member" "eso_gitea_wi" {
  service_account_id = google_service_account.gitea.name
  role               = "roles/iam.workloadIdentityUser"
  member             = "serviceAccount:${var.project_id}.svc.id.goog[external-secrets/external-secrets]"

  depends_on = [google_container_cluster.neuron_platform]
}

resource "google_service_account_iam_member" "eso_gitea_token_creator" {
  service_account_id = google_service_account.gitea.name
  role               = "roles/iam.serviceAccountTokenCreator"
  member             = "serviceAccount:${var.project_id}.svc.id.goog[external-secrets/external-secrets]"

  depends_on = [google_container_cluster.neuron_platform]
}

output "gitea_service_account_email" {
  description = "Gitea GKE SA email — used in the Workload Identity annotation"
  value       = google_service_account.gitea.email
}

output "gitea_database_secret_id" {
  description = "Secret Manager secret ID for the Gitea database URL"
  value       = google_secret_manager_secret.gitea_database_url.secret_id
}