package releaseprep_test

import (
	"os"
	"path/filepath"
	"testing"

	"git.hrafn.xyz/aether/vociferate/internal/releaseprep"
	"github.com/stretchr/testify/require"
	"github.com/stretchr/testify/suite"
)

type PrepareSuite struct {
	suite.Suite
	rootDir string
}

func TestPrepareSuite(t *testing.T) {
	suite.Run(t, new(PrepareSuite))
}

func (s *PrepareSuite) SetupTest() {
	s.rootDir = s.T().TempDir()
	versionDir := filepath.Join(s.rootDir, "internal", "releaseprep", "version")
	require.NoError(s.T(), os.MkdirAll(versionDir, 0o755))

	require.NoError(s.T(), os.WriteFile(
		filepath.Join(versionDir, "version.go"),
		[]byte("package version\n\nconst String = \"1.1.6\"\n"),
		0o644,
	))

	require.NoError(s.T(), os.WriteFile(
		filepath.Join(s.rootDir, "changelog.md"),
		[]byte("# Changelog\n\n## [Unreleased]\n\n### Breaking\n\n### Added\n\n- New thing.\n\n### Fixed\n\n- Old thing.\n\n## [1.1.6] - 2017-12-20\n\n### Fixed\n\n- Historical note.\n"),
		0o644,
	))
}

func (s *PrepareSuite) TestPrepare_UpdatesVersionAndPromotesUnreleasedNotes() {
	err := releaseprep.Prepare(s.rootDir, "v1.1.7", "2026-03-20", releaseprep.Options{})

	require.NoError(s.T(), err)

	versionBytes, err := os.ReadFile(filepath.Join(s.rootDir, "internal", "releaseprep", "version", "version.go"))
	require.NoError(s.T(), err)
	require.Equal(s.T(), "package version\n\nconst String = \"1.1.7\"\n", string(versionBytes))

	changelogBytes, err := os.ReadFile(filepath.Join(s.rootDir, "changelog.md"))
	require.NoError(s.T(), err)
	require.Equal(s.T(), "# Changelog\n\n## [Unreleased]\n\n## [1.1.7] - 2026-03-20\n\n### Breaking\n\n### Added\n\n- New thing.\n\n### Fixed\n\n- Old thing.\n\n## [1.1.6] - 2017-12-20\n\n### Fixed\n\n- Historical note.\n", string(changelogBytes))
}

func (s *PrepareSuite) TestPrepare_ReturnsErrorWhenUnreleasedSectionMissing() {
	require.NoError(s.T(), os.WriteFile(
		filepath.Join(s.rootDir, "changelog.md"),
		[]byte("# Changelog\n\n## [1.1.6] - 2017-12-20\n"),
		0o644,
	))

	err := releaseprep.Prepare(s.rootDir, "1.1.7", "2026-03-20", releaseprep.Options{})

	require.ErrorContains(s.T(), err, "unreleased section")
}

func (s *PrepareSuite) TestPrepare_ReturnsErrorWhenUnreleasedSectionIsEmpty() {
	require.NoError(s.T(), os.WriteFile(
		filepath.Join(s.rootDir, "changelog.md"),
		[]byte("# Changelog\n\n## [Unreleased]\n\n## [1.1.6] - 2017-12-20\n"),
		0o644,
	))

	err := releaseprep.Prepare(s.rootDir, "1.1.7", "2026-03-20", releaseprep.Options{})

	require.ErrorContains(s.T(), err, "unreleased section is empty")
}

func (s *PrepareSuite) TestRecommendedTag_UsesMajorBumpWhenBreakingHeadingExists() {
	tag, err := releaseprep.RecommendedTag(s.rootDir, releaseprep.Options{})

	require.NoError(s.T(), err)
	require.Equal(s.T(), "v2.0.0", tag)
}

func (s *PrepareSuite) TestRecommendedTag_UsesPatchBumpForFixOnlyChanges() {
	require.NoError(s.T(), os.WriteFile(
		filepath.Join(s.rootDir, "changelog.md"),
		[]byte("# Changelog\n\n## [Unreleased]\n\n### Fixed\n\n- Patch note.\n\n## [1.1.6] - 2017-12-20\n"),
		0o644,
	))

	tag, err := releaseprep.RecommendedTag(s.rootDir, releaseprep.Options{})

	require.NoError(s.T(), err)
	require.Equal(s.T(), "v1.1.7", tag)
}

func (s *PrepareSuite) TestRecommendedTag_UsesMajorBumpWhenRemovedEntriesExist() {
	require.NoError(s.T(), os.WriteFile(
		filepath.Join(s.rootDir, "changelog.md"),
		[]byte("# Changelog\n\n## [Unreleased]\n\n### Removed\n\n- Breaking removal.\n\n## [1.1.6] - 2017-12-20\n"),
		0o644,
	))

	tag, err := releaseprep.RecommendedTag(s.rootDir, releaseprep.Options{})

	require.NoError(s.T(), err)
	require.Equal(s.T(), "v2.0.0", tag)
}

func (s *PrepareSuite) TestRecommendedTag_UsesMajorBumpWhenBreakingEntriesExist() {
	require.NoError(s.T(), os.WriteFile(
		filepath.Join(s.rootDir, "changelog.md"),
		[]byte("# Changelog\n\n## [Unreleased]\n\n### Breaking\n\n- Changed API contract.\n\n### Changed\n\n- Updated defaults.\n\n## [1.1.6] - 2017-12-20\n"),
		0o644,
	))

	tag, err := releaseprep.RecommendedTag(s.rootDir, releaseprep.Options{})

	require.NoError(s.T(), err)
	require.Equal(s.T(), "v2.0.0", tag)
}

func (s *PrepareSuite) TestPrepare_UsesCustomVersionFileAndPattern() {
	customVersionFile := filepath.Join("custom", "VERSION.txt")
	require.NoError(s.T(), os.MkdirAll(filepath.Join(s.rootDir, "custom"), 0o755))
	require.NoError(s.T(), os.WriteFile(
		filepath.Join(s.rootDir, customVersionFile),
		[]byte("VERSION=1.1.6\n"),
		0o644,
	))

	err := releaseprep.Prepare(s.rootDir, "1.1.8", "2026-03-20", releaseprep.Options{
		VersionFile:    customVersionFile,
		VersionPattern: `VERSION=([^\n]+)`,
	})

	require.NoError(s.T(), err)

	versionBytes, err := os.ReadFile(filepath.Join(s.rootDir, customVersionFile))
	require.NoError(s.T(), err)
	require.Equal(s.T(), "VERSION=1.1.8\n", string(versionBytes))
}

func (s *PrepareSuite) TestPrepare_AllowsUnchangedVersionValue() {
	require.NoError(s.T(), os.WriteFile(
		filepath.Join(s.rootDir, "internal", "releaseprep", "version", "version.go"),
		[]byte("package version\n\nconst String = \"1.1.6\"\n"),
		0o644,
	))

	err := releaseprep.Prepare(s.rootDir, "1.1.6", "2026-03-20", releaseprep.Options{})

	require.NoError(s.T(), err)

	versionBytes, readErr := os.ReadFile(filepath.Join(s.rootDir, "internal", "releaseprep", "version", "version.go"))
	require.NoError(s.T(), readErr)
	require.Equal(s.T(), "package version\n\nconst String = \"1.1.6\"\n", string(versionBytes))
}

func (s *PrepareSuite) TestRecommendedTag_UsesCustomVersionFileAndPattern() {
	customVersionFile := filepath.Join("custom", "VERSION.txt")
	require.NoError(s.T(), os.MkdirAll(filepath.Join(s.rootDir, "custom"), 0o755))
	require.NoError(s.T(), os.WriteFile(
		filepath.Join(s.rootDir, customVersionFile),
		[]byte("VERSION=2.3.4\n"),
		0o644,
	))
	require.NoError(s.T(), os.WriteFile(
		filepath.Join(s.rootDir, "changelog.md"),
		[]byte("# Changelog\n\n## [Unreleased]\n\n### Added\n\n- Feature.\n\n## [2.3.4] - 2026-03-10\n"),
		0o644,
	))

	tag, err := releaseprep.RecommendedTag(s.rootDir, releaseprep.Options{
		VersionFile:    customVersionFile,
		VersionPattern: `VERSION=([^\n]+)`,
	})

	require.NoError(s.T(), err)
	require.Equal(s.T(), "v2.4.0", tag)
}