defmodule Mix.Tasks.Rustq.Templates.Check do
  @moduledoc false

  use Mix.Task

  @shortdoc "Checks RustQ's Rustler helper templates"

  @fixture Path.expand("../../../test/fixtures/rustler_template_check", __DIR__)
  @generated Path.join(@fixture, "src/generated.rs")

  @impl Mix.Task
  def run(_args) do
    File.write!(@generated, generated_source())

    cargo(["fmt", "--manifest-path", Path.join(@fixture, "Cargo.toml"), "--", "--check"])
    cargo(["check", "--manifest-path", Path.join(@fixture, "Cargo.toml")])

    cargo([
      "clippy",
      "--manifest-path",
      Path.join(@fixture, "Cargo.toml"),
      "--",
      "-D",
      "warnings"
    ])
  end

  defp generated_source do
    RustQ.render!("__splice_items!();", "generated.rs",
      preamble:
        "// This file is generated by mix rustq.templates.check. Do not edit by hand.\n\n",
      splice: [items: generated_items()]
    )
  end

  defp generated_items do
    List.flatten([
      RustQ.Rustler.resource(:Document, fields: [nodes: {:vec, :Node}]),
      RustQ.Rustler.resource_type(:Document),
      RustQ.Rustler.resource_decoder(:Document),
      RustQ.Rustler.term_helpers(type_key: "atoms::r#type()"),
      RustQ.Rustler.term_decoder(:ProgramInput,
        fields: [body: [type: {:vec, "Term<'a>"}, key: "atoms::body()", required: true]]
      ),
      RustQ.Rustler.term_decoder(:IfStatementInput,
        fields: [
          test: [type: "Term<'a>", key: "atoms::test()", required: true],
          consequent: [type: "Term<'a>", key: "atoms::consequent()", required: true],
          alternate: [type: {:option, "Term<'a>"}, key: "atoms::alternate()"]
        ]
      ),
      RustQ.Rustler.nif_struct(:ExText, "Folio.Content.Text",
        attrs: ["allow(dead_code)"],
        fields: [text: :String, size: {:option, :String}]
      ),
      RustQ.Rustler.nif_struct(:ExSpace, "Folio.Content.Space",
        attrs: ["allow(dead_code)"],
        fields: []
      ),
      RustQ.Rustler.tagged_enum(:ExContent,
        attrs: ["allow(dead_code)"],
        tag: "atom_struct()",
        variants: [
          Text: [type: :ExText, module: "Elixir.Folio.Content.Text"],
          Space: [type: :ExSpace, module: "Elixir.Folio.Content.Space"]
        ]
      ),
      RustQ.Rustler.cached_atoms([:ok, {:node_changes, "nodeChanges"}]),
      RustQ.Rustler.term_builders(),
      RustQ.Rustler.nif_term_builders()
    ])
  end

  defp cargo(args) do
    {_, status} = System.cmd("cargo", args, into: IO.stream(), stderr_to_stdout: true)

    if status != 0 do
      Mix.raise("cargo #{Enum.join(args, " ")} failed")
    end
  end
end