require_relative "test_helper"
require "maptool/pmtiles_builder"
require "tmpdir"
require "fileutils"

# Network calls (the protomaps build index, the mapterhorn manifest) are
# never exercised here — same "keep this offline/deterministic" reasoning
# test_helper.rb already gives for /api/plugins staying off the real
# Overpass API — build_offline/build_terrain take fetch_build_url/
# fetch_manifest precisely so tests can swap those out. A fake `pmtiles`
# CLI (PMTILES_BIN) stands in for the real go-pmtiles binary, logging each
# invocation's subcommand + first arg to PMTILES_LOG so tests can assert on
# what actually got called (e.g. "was merge invoked, and with what").
class PmtilesBuilderTest < Minitest::Test
  def setup
    @data_dir = Dir.mktmpdir("maptool-pmtiles-test-data")
    @bin_dir = Dir.mktmpdir("maptool-pmtiles-test-bin")
    @log = File.join(@bin_dir, "pmtiles.log")

    # Output path: $3 for `extract SOURCE OUTPUT --bbox=... --maxzoom=...`
    # and `convert INPUT OUTPUT` alike; the *last* arg for `merge INPUT_1
    # [INPUT_2 ...] OUTPUT`, since its input count varies.
    @pmtiles_ok = File.join(@bin_dir, "pmtiles-ok")
    File.write(@pmtiles_ok, <<~SH)
      #!/bin/sh
      echo "$1 $2" >> "$PMTILES_LOG"
      case "$1" in
        merge)
          for last; do :; done
          echo fake > "$last"
          ;;
        *)
          echo fake > "$3"
          ;;
      esac
    SH
    File.chmod(0o755, @pmtiles_ok)

    @pmtiles_fail = File.join(@bin_dir, "pmtiles-fail")
    File.write(@pmtiles_fail, "#!/bin/sh\necho 'boom' >&2\nexit 1\n")
    File.chmod(0o755, @pmtiles_fail)

    @original_pmtiles_bin = ENV["PMTILES_BIN"]
    ENV["PMTILES_LOG"] = @log
    Maptool::PmtilesBuilder.reset!
  end

  def teardown
    FileUtils.remove_entry(@data_dir)
    FileUtils.remove_entry(@bin_dir)
    ENV["PMTILES_BIN"] = @original_pmtiles_bin
    ENV.delete("PMTILES_LOG")
    Maptool::PmtilesBuilder.reset!
  end

  def log_lines
    File.exist?(@log) ? File.readlines(@log, chomp: true) : []
  end

  # planet.pmtiles always covers the whole world (z0-12); chunk-a/chunk-b
  # are disjoint small regions (z13+), matching Mapterhorn's real shape
  # (see download_urls.json) closely enough to exercise bbox_intersects?
  # and the extract-then-maybe-merge logic without a real manifest fetch.
  def fake_manifest
    [
      { "name" => "planet.pmtiles", "url" => "https://example.com/planet.pmtiles", "min_lon" => -180.0, "min_lat" => -85.0, "max_lon" => 180.0, "max_lat" => 85.0, "min_zoom" => 0, "max_zoom" => 12 },
      { "name" => "chunk-a.pmtiles", "url" => "https://example.com/chunk-a.pmtiles", "min_lon" => 17.0, "min_lat" => 48.0, "max_lon" => 17.5, "max_lat" => 48.5, "min_zoom" => 13, "max_zoom" => 15 },
      { "name" => "chunk-b.pmtiles", "url" => "https://example.com/chunk-b.pmtiles", "min_lon" => 20.0, "min_lat" => 50.0, "max_lon" => 20.5, "max_lat" => 50.5, "min_zoom" => 13, "max_zoom" => 15 },
    ]
  end

  def test_offline_and_terrain_status_start_idle
    assert_equal({ state: "idle" }, Maptool::PmtilesBuilder.offline_status)
    assert_equal({ state: "idle" }, Maptool::PmtilesBuilder.terrain_status)
  end

  def test_build_offline_writes_the_file_and_reports_done
    ENV["PMTILES_BIN"] = @pmtiles_ok
    thread = Maptool::PmtilesBuilder.build_offline(
      [1, 2, 3, 4],
      data_dir: @data_dir,
      fetch_build_url: -> { "https://example.com/fake.pmtiles" },
    )
    thread.join

    assert_path_exists File.join(@data_dir, "offline.pmtiles")
    refute_path_exists File.join(@data_dir, "offline.pmtiles.tmp")
    assert_equal "done", Maptool::PmtilesBuilder.offline_status[:state]
  end

  def test_build_offline_reports_an_error_status_on_non_zero_exit
    ENV["PMTILES_BIN"] = @pmtiles_fail
    thread = Maptool::PmtilesBuilder.build_offline(
      [1, 2, 3, 4],
      data_dir: @data_dir,
      fetch_build_url: -> { "https://example.com/fake.pmtiles" },
    )
    thread.join

    refute_path_exists File.join(@data_dir, "offline.pmtiles")
    status = Maptool::PmtilesBuilder.offline_status
    assert_equal "error", status[:state]
    assert_match(/exited with status/, status[:message])
  end

  def test_build_offline_reports_a_clear_error_when_the_binary_is_missing
    ENV["PMTILES_BIN"] = File.join(@bin_dir, "does-not-exist")
    thread = Maptool::PmtilesBuilder.build_offline(
      [1, 2, 3, 4],
      data_dir: @data_dir,
      fetch_build_url: -> { "https://example.com/fake.pmtiles" },
    )
    thread.join

    status = Maptool::PmtilesBuilder.offline_status
    assert_equal "error", status[:state]
    assert_match(/go-pmtiles installed/, status[:message])
  end

  # fetch_build_url blocks on a Queue so the build is deterministically
  # still "running" when the second call happens, rather than racing a real
  # one to see which state wins.
  def test_build_offline_raises_when_one_is_already_running
    ENV["PMTILES_BIN"] = @pmtiles_ok
    gate = Queue.new
    thread = Maptool::PmtilesBuilder.build_offline([1, 2, 3, 4], data_dir: @data_dir, fetch_build_url: -> { gate.pop })

    assert_raises(Maptool::PmtilesBuilder::BuildError) do
      Maptool::PmtilesBuilder.build_offline([1, 2, 3, 4], data_dir: @data_dir, fetch_build_url: -> { "unused" })
    end
  ensure
    gate.push("https://example.com/fake.pmtiles")
    thread&.join
  end

  # A bbox nowhere near chunk-a/chunk-b — only planet.pmtiles matches, so
  # this should be a single extract straight to the final path, no merge.
  def test_build_terrain_extracts_only_planet_when_no_chunk_intersects
    ENV["PMTILES_BIN"] = @pmtiles_ok
    thread = Maptool::PmtilesBuilder.build_terrain([0, 0, 1, 1], data_dir: @data_dir, fetch_manifest: -> { fake_manifest })
    thread.join

    assert_path_exists File.join(@data_dir, "terrain.pmtiles")
    assert_equal "done", Maptool::PmtilesBuilder.terrain_status[:state]
    assert_equal ["extract https://example.com/planet.pmtiles"], log_lines
  end

  # A bbox inside chunk-a's extent — planet.pmtiles (always) plus that one
  # chunk get extracted, then merged.
  def test_build_terrain_extracts_and_merges_a_single_intersecting_chunk
    ENV["PMTILES_BIN"] = @pmtiles_ok
    thread = Maptool::PmtilesBuilder.build_terrain([48.1, 17.1, 48.2, 17.2], data_dir: @data_dir, fetch_manifest: -> { fake_manifest })
    thread.join

    assert_path_exists File.join(@data_dir, "terrain.pmtiles")
    assert_equal "done", Maptool::PmtilesBuilder.terrain_status[:state]
    extracted = log_lines.select { |line| line.start_with?("extract ") }
    merged = log_lines.select { |line| line.start_with?("merge ") }
    assert_equal ["extract https://example.com/planet.pmtiles", "extract https://example.com/chunk-a.pmtiles"], extracted
    assert_equal 1, merged.size
  end

  # A bbox spanning both chunk-a and chunk-b — planet + both chunks, one
  # 3-way merge.
  def test_build_terrain_merges_multiple_intersecting_chunks
    ENV["PMTILES_BIN"] = @pmtiles_ok
    thread = Maptool::PmtilesBuilder.build_terrain([47.9, 16.9, 50.6, 20.6], data_dir: @data_dir, fetch_manifest: -> { fake_manifest })
    thread.join

    assert_equal "done", Maptool::PmtilesBuilder.terrain_status[:state]
    extracted = log_lines.count { |line| line.start_with?("extract ") }
    assert_equal 3, extracted # planet + chunk-a + chunk-b
    assert_equal 1, log_lines.count { |line| line.start_with?("merge ") }
  end

  def test_build_terrain_reports_a_clear_error_when_the_manifest_is_missing_planet
    ENV["PMTILES_BIN"] = @pmtiles_ok
    thread = Maptool::PmtilesBuilder.build_terrain([0, 0, 1, 1], data_dir: @data_dir, fetch_manifest: -> { fake_manifest.reject { |i| i["name"] == "planet.pmtiles" } })
    thread.join

    status = Maptool::PmtilesBuilder.terrain_status
    assert_equal "error", status[:state]
    assert_match(/missing planet\.pmtiles/, status[:message])
  end

  def test_build_terrain_reports_an_error_status_on_non_zero_exit
    ENV["PMTILES_BIN"] = @pmtiles_fail
    thread = Maptool::PmtilesBuilder.build_terrain([0, 0, 1, 1], data_dir: @data_dir, fetch_manifest: -> { fake_manifest })
    thread.join

    refute_path_exists File.join(@data_dir, "terrain.pmtiles")
    status = Maptool::PmtilesBuilder.terrain_status
    assert_equal "error", status[:state]
    assert_match(/exited with status/, status[:message])
  end

  def test_build_terrain_raises_when_one_is_already_running
    ENV["PMTILES_BIN"] = @pmtiles_ok
    gate = Queue.new
    thread = Maptool::PmtilesBuilder.build_terrain([0, 0, 1, 1], data_dir: @data_dir, fetch_manifest: -> { gate.pop })

    assert_raises(Maptool::PmtilesBuilder::BuildError) do
      Maptool::PmtilesBuilder.build_terrain([0, 0, 1, 1], data_dir: @data_dir, fetch_manifest: -> { "unused" })
    end
  ensure
    gate.push(fake_manifest)
    thread&.join
  end
end