dp_exchange_gemini

defmodule DpExchangeGemini.MixProject do
  use Mix.Project

  # SEED, not a release. CI increments the last segment of whatever it finds here, so
  # `0.1.0` first publishes as `0.1.1`. Hand-editing this to `0.2.0` is how a breaking
  # change is signalled. The bump script matches the attribute assignment below by its
  # exact literal form — do not reformat it, and do not repeat that form anywhere else
  # in this file, comments included, or the script will rewrite the wrong line.
  @version "0.2.9"
  @source_url "https://github.com/DistortionPoint/dp-exchange-gemini"

  def project do
    [
      app: :dp_exchange_gemini,
      version: @version,
      elixir: "~> 1.18",
      elixirc_paths: elixirc_paths(Mix.env()),
      start_permanent: Mix.env() == :prod,
      deps: deps(),
      aliases: aliases(),
      dialyzer: dialyzer(),
      preferred_cli_env: preferred_cli_env(),
      test_coverage: test_coverage(),

      # Hex.pm
      name: "DpExchangeGemini",
      description:
        "EXPERIMENTAL — Gemini venue package for the DpExchange family. Market data, " <>
          "trading and streaming behind the shared DpExchange.Core.Venue facade.",
      package: package(),
      source_url: @source_url,
      docs: docs(),
      usage_rules: usage_rules()
    ]
  end

  # No `mod:` — a library does not start itself. A consumer supervises this venue
  # through `child_spec/1` and decides restart strategy, shutdown order and naming. A
  # consumer that has not asked for Gemini must not find a socket open.
  def application do
    [extra_applications: [:logger]]
  end

  defp elixirc_paths(:test), do: ["lib", "test/support"]
  defp elixirc_paths(_env), do: ["lib"]

  defp deps do
    [
      # The contract. Three-part pin: while Core is 0.x a minor bump may break us, and
      # that is the signal it is meant to send. `0.1.53` is the floor because it is where
      # `Types.OrderBookDelta` shipped — `WsDecode.to_order_book_delta/2` decodes `depth`
      # and `depthFast` frames straight into it, and `Socket` forwards that value without
      # building a book here at all (see `socket.ex`'s moduledoc). A lower resolution has
      # no `OrderBookDelta` module to alias; `~> 0.1.48` previously allowed one and only
      # compiled here because CI always resolves the newest allowed version.
      # `0.2.6` is the floor now, and unlike the history below it is a HARD one: `Feed`
      # calls `Core.Fanout.max_queue_len!/2` in `init/1` and `Core.Fanout.deliver/4` on
      # every payload, and neither existed before 0.2.6. Against a lower Core this package
      # does not merely misbehave, it fails to compile — which is the good outcome, and the
      # reason the floor is stated rather than left to `script/check_dependency_floor.sh` to
      # discover. The older floor history is kept above because its lesson is the one that
      # keeps applying: a floor is only correct once it has been RESOLVED and compiled
      # against, never once it has been reasoned about.
      #
      # `0.3.1` is a MINOR bump, and the signal is deliberate: Core 0.3.0 deleted
      # `Core.DataProvider` and `Core.FeedBehaviour`, two contracts with zero implementers.
      # Nothing in this package referenced either, so there is no code change here — the
      # floor moves because a pin of `~> 0.2.8` would not resolve 0.3.x, which is the pin
      # doing its job rather than a problem to route around. Resolved and compiled against
      # before this line was written, per the lesson recorded below: a floor is only correct
      # once it has been RESOLVED, never once it has been reasoned about.
      #
      {:dp_exchange_core, "~> 0.3.1"},

      # This venue's own transport. Core ships no transport library at any strength —
      # a venue that speaks WebSocket ships what it needs to speak it.
      {:websockex, "~> 0.4"},
      {:jason, "~> 1.4"},
      {:decimal, "~> 2.0"},

      # Dev/Test
      {:usage_rules, "~> 1.2", only: :dev},
      {:ex_doc, "~> 0.34", only: :dev, runtime: false},
      {:credo, "~> 1.7", only: [:dev, :test], runtime: false},
      {:dialyxir, "~> 1.4", only: [:dev, :test], runtime: false},
      {:sobelow, "~> 0.13", only: [:dev, :test], runtime: false},

      # Exercises the REST pipeline through Req's test seam, so tier-1 tests reach no
      # network. Never ships.
      {:plug, "~> 1.16", only: :test}
    ]
  end

  defp test_coverage, do: [threshold: 90, ignore_modules: []]

  defp aliases do
    [quality: ["format --check-formatted", "credo --strict", "dialyzer", "sobelow --config"]]
  end

  defp dialyzer do
    [plt_add_apps: [:mix, :ex_unit], plt_file: {:no_warn, "priv/plts/dialyzer.plt"}]
  end

  defp preferred_cli_env, do: [quality: :test]

  defp package do
    [
      licenses: ["MIT"],
      links: %{"GitHub" => @source_url},
      maintainers: ["bcatherall"],

      # `files:` belongs HERE, not at the project level. Hex reads `package[:files]`; a
      # `files:` in `project/0` is silently ignored and Hex ships its own defaults —
      # which puts `priv/plts/dialyzer.plt` in the tarball and leaves out anything you
      # meant to add. Nothing warns. Inspect `mix hex.build` before every publish.
      #
      # `priv/` is absent because the only thing in it is the dialyzer PLT.
      # `config/` is absent: it governs this package's own dev and test, never a
      # consumer's.
      files: [
        "lib",
        "mix.exs",
        ".formatter.exs",
        "README.md",
        "LICENSE",
        "CHANGELOG.md",
        "AGENTS.md",
        "usage-rules.md",
        "docs/reference"
      ]
    ]
  end

  defp docs do
    [
      main: "DpExchange.Gemini",
      extras: ["README.md", "CHANGELOG.md", "usage-rules.md"],
      source_ref: "v#{@version}"
    ]
  end

  defp usage_rules, do: [file: "AGENTS.md", usage_rules: [:usage_rules]]
end