neiam /gitgud

defmodule GitGud.RepositoriesCommitterStatsTest do
  use GitGud.DataCase, async: false

  alias GitGud.Repo
  alias GitGud.Repositories
  alias GitGud.Repositories.GitCommit
  alias GitGud.Repositories.GitCommitDiffstat

  import GitGud.ForgeFixtures

  defp insert_commit(rid, sha_hex, attrs) do
    base = %{
      repository_id: rid,
      sha: hex(sha_hex),
      tree_sha: hex(String.duplicate("0", 40)),
      parent_shas: [],
      author_name: "Alice",
      author_email: "alice@example",
      authored_at: ~U[2026-01-01 00:00:00Z],
      committer_name: "Alice",
      committer_email: "alice@example",
      committed_at: ~U[2026-01-01 00:00:00Z],
      message: "msg"
    }

    Repo.insert_all(GitCommit, [Map.merge(base, attrs)])
  end

  defp insert_diffstat(rid, sha_hex, insertions, deletions) do
    Repo.insert_all(GitCommitDiffstat, [
      %{
        repository_id: rid,
        sha: hex(sha_hex),
        files_changed: 1,
        insertions: insertions,
        deletions: deletions,
        paths: []
      }
    ])
  end

  defp hex(s), do: Base.decode16!(s, case: :mixed)

  setup do
    {_user, repo} = repository_fixture()
    {:ok, repo: repo}
  end

  test "groups by author_email, sorted by commits desc", %{repo: repo} do
    insert_commit(repo.id, String.duplicate("1", 40), %{
      author_email: "alice@example",
      author_name: "Alice",
      authored_at: ~U[2026-01-01 10:00:00Z]
    })

    insert_commit(repo.id, String.duplicate("2", 40), %{
      author_email: "alice@example",
      author_name: "Alice",
      authored_at: ~U[2026-01-02 10:00:00Z]
    })

    insert_commit(repo.id, String.duplicate("3", 40), %{
      author_email: "bob@example",
      author_name: "Bob",
      authored_at: ~U[2026-01-03 10:00:00Z]
    })

    assert [alice, bob] = Repositories.committer_stats(repo)
    assert alice.email == "alice@example"
    assert alice.commits == 2
    assert bob.email == "bob@example"
    assert bob.commits == 1
  end

  test "sums insertions + deletions via diffstats join", %{repo: repo} do
    sha1 = String.duplicate("1", 40)
    sha2 = String.duplicate("2", 40)

    insert_commit(repo.id, sha1, %{author_email: "a@e", author_name: "A"})
    insert_commit(repo.id, sha2, %{author_email: "a@e", author_name: "A"})
    insert_diffstat(repo.id, sha1, 10, 3)
    insert_diffstat(repo.id, sha2, 5, 1)

    assert [%{insertions: 15, deletions: 4}] = Repositories.committer_stats(repo)
  end

  test "commits without diffstats still counted (zeros for churn)", %{repo: repo} do
    insert_commit(repo.id, String.duplicate("1", 40), %{author_email: "a@e", author_name: "A"})
    # No diffstat row.

    assert [%{commits: 1, insertions: 0, deletions: 0}] = Repositories.committer_stats(repo)
  end

  test "first_at / last_at span all of the author's commits", %{repo: repo} do
    insert_commit(repo.id, String.duplicate("1", 40), %{
      author_email: "a@e",
      authored_at: ~U[2026-01-01 00:00:00Z]
    })

    insert_commit(repo.id, String.duplicate("2", 40), %{
      author_email: "a@e",
      authored_at: ~U[2026-05-01 00:00:00Z]
    })

    insert_commit(repo.id, String.duplicate("3", 40), %{
      author_email: "a@e",
      authored_at: ~U[2026-03-01 00:00:00Z]
    })

    assert [%{first_at: ~U[2026-01-01 00:00:00Z], last_at: ~U[2026-05-01 00:00:00Z]}] =
             Repositories.committer_stats(repo)
  end

  test "stats are scoped per repository", %{repo: repo} do
    {_user2, other} = repository_fixture()

    insert_commit(repo.id, String.duplicate("1", 40), %{author_email: "a@e"})
    insert_commit(other.id, String.duplicate("2", 40), %{author_email: "b@e"})

    assert [%{email: "a@e"}] = Repositories.committer_stats(repo)
    assert [%{email: "b@e"}] = Repositories.committer_stats(other)
  end

  test "empty repo → []", %{repo: repo} do
    assert [] = Repositories.committer_stats(repo)
  end
end