# Provider catalog contract — declarative shape every provider exports via
# its `nickel/catalog.ncl`. Round-trip target: the Rust types in
# `libre-forge-fleet/crates/fleet-protocol/src/provider.rs`
# (BillingPolicy, InstanceType, Supports, Arch, Rounding). Field names and
# allowed string-enum values match Rust's `#[serde(rename_all = "snake_case")]`
# representation so `nickel export --format json` produces JSON the daemon
# can deserialize directly.
#
# Add a new provider:
#   1. Copy `hetzner/nickel/catalog.ncl` to `<new>/nickel/catalog.ncl`.
#   2. Populate `instance_types`, `billing_policy`, `supports` for that cloud.
#   3. Run `nickel export --import-path <prov_root> <new>/nickel/catalog.ncl`
#      and verify the JSON deserialises as `ProviderCatalog` in fleet-protocol.

let _Arch = std.contract.from_predicate (fun v =>
  std.is_string v && (v == "x86_64" || v == "arm64")
) in

let _Rounding = std.contract.from_predicate (fun v =>
  std.is_string v && (v == "ceil_hour" || v == "ceil_minute" || v == "ceil_second" || v == "exact")
) in

let _NonNeg = std.contract.from_predicate (fun v =>
  std.is_number v && v >= 0
) in

{
  # Cents per hour, sub-cent granularity. 1 EUR = 10_000 Cents.
  # See fleet-protocol::provider::Cents (i64).
  InstanceType = {
    id           | String,
    arch         | _Arch,
    cpu          | _NonNeg,
    ram_gb       | _NonNeg,
    disk_gb      | _NonNeg,
    hourly_cents | _NonNeg,
  },

  BillingPolicy = {
    granularity_s     | _NonNeg | doc "smallest billable increment in seconds",
    minimum_s         | _NonNeg | doc "lower bound applied after granularity rounding",
    monthly_cap_hours | _NonNeg | doc "hours after which price plateaus inside a calendar month",
    rounding          | _Rounding,
  },

  Supports = {
    resize                 | Bool | default = false,
    resize_needs_reboot    | Bool | default = false,
    stop_start_free        | Bool | default = false,
    spot                   | Bool | default = false,
    sustained_use_discount | Bool | default = false,
  },

  # Top-level shape every <provider>/nickel/catalog.ncl returns.
  ProviderCatalog = {
    name           | String              | doc "stable provider id matching fleet-protocol::Provider::name()",
    instance_types | Array InstanceType,
    billing_policy | BillingPolicy,
    supports       | Supports,
  },
}