defmodule Mv.Membership.MembersPDFTest do
  @moduledoc """
  Tests for MembersPDF module.

  Tests verify that the module correctly:
  - Loads the Typst template
  - Converts export data to template format
  - Generates valid PDF binary (starts with "%PDF")
  - Handles errors gracefully
  """
  use ExUnit.Case, async: true

  alias Mv.Config
  alias Mv.Membership.MembersPDF

  describe "render/1" do
    test "rejects export when row count exceeds limit" do
      max_rows = Config.pdf_export_row_limit()
      rows_over_limit = max_rows + 1

      export_data = %{
        columns: [
          %{key: "first_name", kind: :member_field, label: "Vorname"}
        ],
        rows: Enum.map(1..rows_over_limit, fn i -> ["Member #{i}"] end),
        meta: %{
          generated_at: "2024-01-15T14:30:00Z",
          member_count: rows_over_limit
        }
      }

      result = MembersPDF.render(export_data)

      assert {:error, {:row_limit_exceeded, ^rows_over_limit, ^max_rows}} = result
    end

    test "allows export when row count equals limit" do
      max_rows = Config.pdf_export_row_limit()

      export_data = %{
        columns: [
          %{key: "first_name", kind: :member_field, label: "Vorname"}
        ],
        rows: Enum.map(1..max_rows, fn i -> ["Member #{i}"] end),
        meta: %{
          generated_at: "2024-01-15T14:30:00Z",
          member_count: max_rows
        }
      }

      result = MembersPDF.render(export_data)

      assert {:ok, pdf_binary} = result
      assert String.starts_with?(pdf_binary, "%PDF")
    end

    test "allows export when row count is below limit" do
      max_rows = Config.pdf_export_row_limit()
      rows_below_limit = max(1, max_rows - 10)

      export_data = %{
        columns: [
          %{key: "first_name", kind: :member_field, label: "Vorname"}
        ],
        rows: Enum.map(1..rows_below_limit, fn i -> ["Member #{i}"] end),
        meta: %{
          generated_at: "2024-01-15T14:30:00Z",
          member_count: rows_below_limit
        }
      }

      result = MembersPDF.render(export_data)

      assert {:ok, pdf_binary} = result
      assert String.starts_with?(pdf_binary, "%PDF")
    end

    test "generates valid PDF from minimal dataset" do
      export_data = %{
        columns: [
          %{key: "first_name", kind: :member_field, label: "Vorname"},
          %{key: "last_name", kind: :member_field, label: "Nachname"}
        ],
        rows: [
          ["Max", "Mustermann"],
          ["Anna", "Schmidt"]
        ],
        meta: %{
          generated_at: "2024-01-15T14:30:00Z",
          member_count: 2
        }
      }

      result = MembersPDF.render(export_data)

      assert {:ok, pdf_binary} = result
      assert is_binary(pdf_binary)
      assert String.starts_with?(pdf_binary, "%PDF")
      assert byte_size(pdf_binary) > 1000
    end

    test "generates valid PDF with custom fields and computed fields" do
      export_data = %{
        columns: [
          %{key: "first_name", kind: :member_field, label: "Vorname"},
          %{key: "last_name", kind: :member_field, label: "Nachname"},
          %{key: "email", kind: :member_field, label: "E-Mail"},
          %{key: :membership_fee_status, kind: :computed, label: "Beitragsstatus"},
          %{
            key: "550e8400-e29b-41d4-a716-446655440000",
            kind: :custom_field,
            label: "Mitgliedsnummer",
            custom_field: %{
              id: "550e8400-e29b-41d4-a716-446655440000",
              name: "Mitgliedsnummer",
              value_type: :string
            }
          }
        ],
        rows: [
          ["Max", "Mustermann", "max@example.com", "paid", "M-2024-001"],
          ["Anna", "Schmidt", "anna@example.com", "unpaid", "M-2024-002"]
        ],
        meta: %{
          generated_at: "2024-01-15T14:30:00Z",
          member_count: 2
        }
      }

      result = MembersPDF.render(export_data)

      assert {:ok, pdf_binary} = result
      assert is_binary(pdf_binary)
      assert String.starts_with?(pdf_binary, "%PDF")
    end

    test "maintains deterministic column and row order" do
      export_data = %{
        columns: [
          %{key: "first_name", kind: :member_field, label: "Vorname"},
          %{key: "last_name", kind: :member_field, label: "Nachname"},
          %{key: "email", kind: :member_field, label: "E-Mail"}
        ],
        rows: [
          ["Max", "Mustermann", "max@example.com"],
          ["Anna", "Schmidt", "anna@example.com"],
          ["Peter", "Müller", "peter@example.com"]
        ],
        meta: %{
          generated_at: "2024-01-15T14:30:00Z",
          member_count: 3
        }
      }

      # Render twice and verify identical output
      {:ok, pdf1} = MembersPDF.render(export_data)
      {:ok, pdf2} = MembersPDF.render(export_data)

      assert pdf1 == pdf2
      assert String.starts_with?(pdf1, "%PDF")
      assert String.starts_with?(pdf2, "%PDF")
    end

    test "returns error when template file is missing" do
      # Temporarily rename template to simulate missing file
      template_path =
        Path.join(Application.app_dir(:mv, "priv"), "pdf_templates/members_export.typ")

      original_content = File.read!(template_path)
      File.rm(template_path)

      export_data = %{
        columns: [%{key: "first_name", kind: :member_field, label: "Vorname"}],
        rows: [["Max"]],
        meta: %{generated_at: "2024-01-15T14:30:00Z", member_count: 1}
      }

      result = MembersPDF.render(export_data)

      assert {:error, {:template_not_found, _reason}} = result

      # Restore template
      File.write!(template_path, original_content)
    end

    test "handles empty rows gracefully" do
      export_data = %{
        columns: [
          %{key: "first_name", kind: :member_field, label: "Vorname"},
          %{key: "last_name", kind: :member_field, label: "Nachname"}
        ],
        rows: [],
        meta: %{
          generated_at: "2024-01-15T14:30:00Z",
          member_count: 0
        }
      }

      result = MembersPDF.render(export_data)

      assert {:ok, pdf_binary} = result
      assert is_binary(pdf_binary)
      assert String.starts_with?(pdf_binary, "%PDF")
    end

    test "handles many columns correctly" do
      # Test with 10 columns to ensure dynamic column width calculation works
      columns =
        Enum.map(1..10, fn i ->
          %{key: "field_#{i}", kind: :member_field, label: "Feld #{i}"}
        end)

      export_data = %{
        columns: columns,
        rows: [Enum.map(1..10, &"Wert #{&1}")],
        meta: %{
          generated_at: "2024-01-15T14:30:00Z",
          member_count: 1
        }
      }

      result = MembersPDF.render(export_data)

      assert {:ok, pdf_binary} = result
      assert is_binary(pdf_binary)
      assert String.starts_with?(pdf_binary, "%PDF")
    end

    test "creates and cleans up temp directory" do
      export_data = %{
        columns: [%{key: "first_name", kind: :member_field, label: "Vorname"}],
        rows: [["Max"]],
        meta: %{
          generated_at: "2024-01-15T14:30:00Z",
          member_count: 1
        }
      }

      # Get temp base directory
      temp_base = System.tmp_dir!()

      # Count temp directories before
      before_count =
        temp_base
        |> File.ls!()
        |> Enum.count(fn name -> String.starts_with?(name, "mv_pdf_export_") end)

      result = MembersPDF.render(export_data)

      assert {:ok, _pdf_binary} = result

      # Wait a bit for cleanup (async cleanup might take a moment)
      Process.sleep(100)

      # Count temp directories after
      after_count =
        temp_base
        |> File.ls!()
        |> Enum.count(fn name -> String.starts_with?(name, "mv_pdf_export_") end)

      # Should have same or fewer temp dirs (cleanup should have run)
      assert after_count <= before_count + 1
    end
  end
end