import core from "grapheme/core"

struct Release {
  service: String
  step: Float
  status: String
}

glyph Main { Rollout }

query Rollout on Any -> Release {
  Release { service: "checkout", step: 0.0, status: "ramping" }
  |> Ramp
}

iterator Ramp on Release -> Release @core_default @loop(max: 10, merge: "replace") {
  match $state.status {
    case complete => return
    default => Advance
  }
}

mutation Advance on Release -> Release @core_default {
  inc_field(field: "step")
  |> if $state.step >= 3.0 then set { status: "complete" } else set { status: "ramping" }
}