package engine

import (
	"path/filepath"
	"testing"
	"testing/fstest"
)

func TestLayeredDestinationDiagnosticsUseEffectivePathsAndAuthoredLocations(t *testing.T) {
	t.Parallel()

	t.Run("strict conflict retains both source locations", func(t *testing.T) {
		t.Parallel()
		loaded, err := LoadLayered(
			Input{Source: NoSource()},
			testSecretBinding(),
			LayeredOptions[map[string]any]{Underlays: []Underlay{{Inputs: []Input{
				{Source: Bytes("left", []byte("section:\n  value: left\n")), Destination: Keys("application")},
				{Source: Bytes("right", []byte("section:\n  value: right\n")), Destination: Keys("application")},
			}}}},
		)
		if loaded != nil {
			t.Fatalf("conflicting load returned a result: %#v", loaded)
		}
		diagnostic := firstDestinationDiagnostic(t, err)
		if diagnostic.Code != CodeComposeConflict || diagnostic.Path.String() != "/application/section/value" {
			t.Fatalf("conflict diagnostic = %#v", diagnostic)
		}
		if diagnostic.Primary == nil || diagnostic.Primary.SourceID != "source-1" || diagnostic.Primary.Line != 2 {
			t.Fatalf("primary location = %#v", diagnostic.Primary)
		}
		if len(diagnostic.Related) != 1 || diagnostic.Related[0].SourceID != "source-2" || diagnostic.Related[0].Line != 2 {
			t.Fatalf("related locations = %#v", diagnostic.Related)
		}
	})

	t.Run("decode failure keeps effective path and content line", func(t *testing.T) {
		t.Parallel()
		type section struct {
			Count int `yaml:"count"`
		}
		type config struct {
			Application struct {
				Section section `yaml:"section"`
			} `yaml:"application"`
		}
		loaded, err := LoadLayered(
			Input{Source: Bytes("main", []byte("section:\n  count: invalid\n")), Destination: Keys("application")},
			testSecretBinding(),
			LayeredOptions[config]{},
		)
		if loaded != nil {
			t.Fatalf("invalid load returned a result: %#v", loaded)
		}
		diagnostic := firstDestinationDiagnostic(t, err)
		if diagnostic.Code != CodeDecodeType || diagnostic.Path.String() != "/application/section/count" {
			t.Fatalf("decode diagnostic = %#v", diagnostic)
		}
		if diagnostic.Primary == nil || diagnostic.Primary.SourceID != "source-1" || diagnostic.Primary.Line != 2 {
			t.Fatalf("decode location = %#v", diagnostic.Primary)
		}
	})

	t.Run("imported version failure uses effective path and import source", func(t *testing.T) {
		t.Parallel()
		directory := t.TempDir()
		writeImportFile(t, directory, "main.yml", "configkit: {imports: [{path: fragment.yml}]}\n")
		writeImportFile(t, directory, "fragment.yml", "version: forbidden\n")
		rule := &VersionRule{Path: Keys("application", "version"), Check: func(Version, *Validation) error { return nil }}
		loaded, err := LoadLayered(
			Input{Source: NoSource()},
			testSecretBinding(),
			LayeredOptions[map[string]any]{
				Definition: Definition[map[string]any]{Version: rule},
				Underlays: []Underlay{{Inputs: []Input{{
					Source: File(filepath.Join(directory, "main.yml")), Imports: true, Destination: Keys("application"),
				}}}},
			},
		)
		if loaded != nil {
			t.Fatalf("invalid import returned a result: %#v", loaded)
		}
		diagnostic := firstDestinationDiagnostic(t, err)
		if diagnostic.Code != CodeImportVersion || diagnostic.Path.String() != "/application/version" {
			t.Fatalf("import version diagnostic = %#v", diagnostic)
		}
		if diagnostic.Primary == nil || diagnostic.Primary.SourceID != "source-2" || diagnostic.Primary.Line != 1 {
			t.Fatalf("import version location = %#v", diagnostic.Primary)
		}
	})

	t.Run("invalid destination has no fictional source location", func(t *testing.T) {
		t.Parallel()
		loaded, err := LoadLayered(
			Input{Source: Bytes("main", []byte("value: present\n")), Destination: Keys("configkit")},
			testSecretBinding(),
			LayeredOptions[map[string]any]{},
		)
		if loaded != nil {
			t.Fatalf("invalid destination returned a result: %#v", loaded)
		}
		diagnostic := firstDestinationDiagnostic(t, err)
		if diagnostic.Code != CodeOptionsInvalid || diagnostic.Path.String() != "/configkit" || diagnostic.Primary != nil {
			t.Fatalf("invalid destination diagnostic = %#v", diagnostic)
		}
	})

	t.Run("malformed source directive keeps its local path and location", func(t *testing.T) {
		t.Parallel()
		filesystem := NewFilesystem("bundle", fstest.MapFS{
			"main.yml": &fstest.MapFile{Data: []byte("configkit: {imports: [true]}\nvalue: present\n")},
		})
		loaded, err := LoadLayered(
			Input{Source: filesystem.File("main.yml"), Imports: true, Destination: Keys("application")},
			testSecretBinding(),
			LayeredOptions[map[string]any]{},
		)
		if loaded != nil {
			t.Fatalf("malformed directive returned a result: %#v", loaded)
		}
		diagnostic := firstDestinationDiagnostic(t, err)
		if diagnostic.Code != CodeImportInvalid || diagnostic.Path.String() != "/configkit/imports/0" {
			t.Fatalf("malformed directive diagnostic = %#v", diagnostic)
		}
		if diagnostic.Primary == nil || diagnostic.Primary.SourceID != "source-1" || diagnostic.Primary.Line != 1 {
			t.Fatalf("malformed directive location = %#v", diagnostic.Primary)
		}
	})
}

func firstDestinationDiagnostic(t *testing.T, err error) Diagnostic {
	t.Helper()
	loadError, ok := err.(*LoadError)
	if !ok {
		t.Fatalf("load error = %#v", err)
	}
	diagnostics := loadError.Diagnostics()
	if len(diagnostics) == 0 {
		t.Fatal("load error has no diagnostics")
	}
	return diagnostics[0]
}