defmodule CljElixir.CompilerTest do
  use ExUnit.Case, async: true

  describe "compile_string/2" do
    test "returns {:ok, ast} for valid source" do
      # This test exercises the full pipeline. It requires Reader and Transformer
      # to be implemented. Until then, it verifies the Compiler module compiles
      # and the function heads are correct.
      source = "(+ 1 2)"

      case CljElixir.Compiler.compile_string(source) do
        {:ok, _ast} ->
          :ok

        {:error, diagnostics} ->
          # Expected when Reader/Transformer are not yet implemented
          assert is_list(diagnostics)
      end
    end

    test "returns {:error, diagnostics} for missing file" do
      {:error, diagnostics} = CljElixir.Compiler.compile_file("/nonexistent/path.clje")
      assert is_list(diagnostics)
      assert length(diagnostics) > 0

      [diag | _] = diagnostics
      assert diag.severity == :error
      assert diag.message =~ "could not read file"
    end

    test "passes file option through" do
      source = "(+ 1 2)"
      opts = [file: "test.clje"]

      case CljElixir.Compiler.compile_string(source, opts) do
        {:ok, _ast} -> :ok
        {:error, _diagnostics} -> :ok
      end
    end
  end

  describe "eval_string/2" do
    test "returns {:ok, result, bindings} or {:error, diagnostics}" do
      source = "(+ 1 2)"

      case CljElixir.Compiler.eval_string(source) do
        {:ok, result, bindings} ->
          assert result == 3
          assert is_list(bindings)

        {:error, diagnostics} ->
          # Expected when Reader/Transformer are not yet implemented
          assert is_list(diagnostics)
      end
    end
  end

  describe "compile_to_beam/2" do
    test "returns {:ok, modules} or {:error, diagnostics}" do
      source = ~S"""
      (defmodule TestBeamCompile
        (defn hello [] :world))
      """

      case CljElixir.Compiler.compile_to_beam(source) do
        {:ok, modules} ->
          assert is_list(modules)

          assert Enum.any?(modules, fn {mod, _binary} ->
                   mod == TestBeamCompile
                 end)

        {:error, diagnostics} ->
          # Expected when Reader/Transformer are not yet implemented
          assert is_list(diagnostics)
      end
    end
  end

  describe "compile_file/2" do
    test "reads file and compiles" do
      # Write a temp file
      tmp_dir = System.tmp_dir!()
      path = Path.join(tmp_dir, "test_compile_#{System.unique_integer([:positive])}.clje")
      File.write!(path, "(+ 1 2)")

      try do
        case CljElixir.Compiler.compile_file(path) do
          {:ok, _ast} -> :ok
          {:error, _diagnostics} -> :ok
        end
      after
        File.rm(path)
      end
    end

    test "returns error for nonexistent file" do
      {:error, [diag | _]} = CljElixir.Compiler.compile_file("/does/not/exist.clje")
      assert diag.severity == :error
      assert diag.message =~ "could not read file"
    end
  end

  describe "eval_file/2" do
    test "reads file, compiles, and evaluates" do
      tmp_dir = System.tmp_dir!()
      path = Path.join(tmp_dir, "test_eval_#{System.unique_integer([:positive])}.clje")
      File.write!(path, "(+ 1 2)")

      try do
        case CljElixir.Compiler.eval_file(path) do
          {:ok, 3, _bindings} -> :ok
          {:ok, _result, _bindings} -> :ok
          {:error, _diagnostics} -> :ok
        end
      after
        File.rm(path)
      end
    end
  end

  describe "compile_file_to_beam/2" do
    test "compiles file and writes .beam output" do
      tmp_dir = System.tmp_dir!()
      source_path = Path.join(tmp_dir, "test_beam_#{System.unique_integer([:positive])}.clje")
      output_dir = Path.join(tmp_dir, "beam_output_#{System.unique_integer([:positive])}")

      File.write!(source_path, ~S"""
      (defmodule TestBeamOutput
        (defn greet [] "hi"))
      """)

      try do
        case CljElixir.Compiler.compile_file_to_beam(source_path, output_dir: output_dir) do
          {:ok, modules} ->
            assert is_list(modules)
            # Check .beam files were written
            beam_files = Path.wildcard(Path.join(output_dir, "*.beam"))
            assert length(beam_files) > 0

          {:error, _diagnostics} ->
            # Expected when Reader/Transformer are not yet implemented
            :ok
        end
      after
        File.rm(source_path)
        File.rm_rf(output_dir)
      end
    end
  end
end