package layer_test

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

	"github.com/netkingdom/flex-auth/internal/layer"
)

func writeRepo(t *testing.T, root, name, intent, declFile string) {
	t.Helper()
	dir := filepath.Join(root, name)
	if err := os.MkdirAll(dir, 0o755); err != nil {
		t.Fatal(err)
	}
	if intent != "" {
		body := "---\nlayer: " + intent + "\nrole: PDP\n---\n\n# x\n"
		if err := os.WriteFile(filepath.Join(dir, "INTENT.md"), []byte(body), 0o644); err != nil {
			t.Fatal(err)
		}
	}
	if declFile != "" {
		if err := os.WriteFile(filepath.Join(dir, "layer.yaml"), []byte("layer: "+declFile+"\n"), 0o644); err != nil {
			t.Fatal(err)
		}
	}
}

// The finding FLEX-WP-0030 B1 rests on: §11 accepts either form and does not
// say which governs when a repository carries both and they disagree.
func TestSurveyDetectsFormsDisagreeingWithinOneRepo(t *testing.T) {
	root := t.TempDir()
	writeRepo(t, root, "peer", "Engine", "engine")

	rows, err := layer.SurveyDeclarations(root, []string{"peer"})
	if err != nil {
		t.Fatal(err)
	}
	if len(rows) != 1 {
		t.Fatalf("rows = %d; want 1", len(rows))
	}
	if !rows[0].SelfDisagrees() {
		t.Fatal("Engine vs engine across the two §11 forms was not reported as disagreement")
	}
	if got := len(layer.SelfDisagreeing(rows)); got != 1 {
		t.Fatalf("SelfDisagreeing = %d; want 1", got)
	}
}

// Case IS folded now. GH-DEC-2026-017 §2 ruled comparison ASCII case-insensitive
// and requires a run to fold before comparing. This test was the inverse
// assertion while that was the open question; it is inverted rather than
// deleted, so the ruling is visible in the place the old behaviour lived.
func TestSurveyFoldsCaseAfterGHDEC017(t *testing.T) {
	root := t.TempDir()
	writeRepo(t, root, "peer", "", "engine")

	rows, _ := layer.SurveyDeclarations(root, []string{"peer"})
	if !rows[0].File.InVocabulary {
		t.Fatal(`"engine" was rejected; a lowercase declaration is conforming, not tolerated`)
	}
	if rows[0].File.Canonical != "Engine" {
		t.Fatalf("Canonical = %q; want the §4 column spelling Engine", rows[0].File.Canonical)
	}
}

// The two forms disagreeing only in spelling is still reported — precedence
// says which value is the repository's answer, it does not say the
// disagreement did not happen (GH-DEC-2026-017 §1) — but it is not a
// disagreement about a LAYER.
func TestSpellingDisagreementIsReportedButIsNotALayerDisagreement(t *testing.T) {
	root := t.TempDir()
	writeRepo(t, root, "peer", "Engine", "engine")

	rows, _ := layer.SurveyDeclarations(root, []string{"peer"})
	if !rows[0].SelfDisagrees() {
		t.Fatal("the form disagreement was not reported; it is a finding in its own right")
	}
	if rows[0].DisagreesOnLayer() {
		t.Fatal("Engine vs engine was reported as a disagreement about a layer; two spellings of Engine do not describe two boundaries")
	}
	if rows[0].Layer() != "Engine" {
		t.Fatal("INTENT.md governs; the repository's answer is its INTENT.md value")
	}
}

// Taxonomy is in the vocabulary, and railiance-master — which declares it and
// is not a §4 row — is a volunteer, not a non-conformance.
func TestTaxonomyVolunteerIsInVocabularyAndOutOfScope(t *testing.T) {
	root := t.TempDir()
	writeRepo(t, root, "railiance-master", "Taxonomy", "")

	rows, _ := layer.SurveyDeclarations(root, []string{"railiance-master"})
	if !rows[0].Intent.InVocabulary {
		t.Fatal("Taxonomy was rejected: §3.1 defines it and §4 catalogues it twice")
	}
	if rows[0].InCatalog {
		t.Fatal("railiance-master was treated as a §4 catalog row")
	}
	if got := layer.VolunteerDeclarations(rows); len(got) != 1 || got[0] != "railiance-master" {
		t.Fatalf("VolunteerDeclarations = %v; want [railiance-master]", got)
	}
}

// §11 binds §4, and A11 requires a run to state what it ranged over.
func TestRunStatesItsScope(t *testing.T) {
	repos := []string{"flex-auth", "gate-house", "railiance-master"}

	catalog := layer.CatalogScope(repos)
	if catalog.Statement == "" {
		t.Fatal("a scope with no statement cannot be acted on")
	}
	if len(catalog.Repos) != 2 {
		t.Fatalf("CatalogScope = %v; want the two §4 rows (flex-auth is the access-engine row)", catalog.Repos)
	}
	if !layer.InCatalog("flex-auth") || !layer.InCatalog("access-engine") {
		t.Fatal("the §4 row resolves under both names until the ruled rename lands")
	}
	if layer.InCatalog("railiance-master") {
		t.Fatal("railiance-master is not a §4 row")
	}

	estate := layer.EstateScope(repos)
	if len(estate.Repos) != 3 || estate.Name == catalog.Name {
		t.Fatal("the estate-wide run and the §4 run must be distinguishable; they answer different questions")
	}
}

func TestSurveyReportsMissingDeclaration(t *testing.T) {
	root := t.TempDir()
	writeRepo(t, root, "silent", "", "")

	rows, _ := layer.SurveyDeclarations(root, []string{"silent"})
	if rows[0].Declared() {
		t.Fatal("a repository with neither form was reported as declared")
	}
	if got := layer.Undeclared(rows); len(got) != 1 || got[0] != "silent" {
		t.Fatalf("Undeclared = %v; want [silent]", got)
	}
}

// A single well-formed declaration must not be reported as disagreeing with
// itself — flex-auth is exactly this shape.
func TestSurveySingleFormIsNotDisagreement(t *testing.T) {
	root := t.TempDir()
	writeRepo(t, root, "solo", "Engine", "")

	rows, _ := layer.SurveyDeclarations(root, []string{"solo"})
	if rows[0].SelfDisagrees() {
		t.Fatal("a repository with only INTENT.md was reported as self-disagreeing")
	}
	if !rows[0].Intent.InVocabulary {
		t.Fatal(`"Engine" was rejected from the §3 vocabulary`)
	}
}

// A peer's declaration is read for layer and role only. A peer carrying a field
// flex-auth also uses, in a different shape, must not drop out of the survey.
func TestPeerWithForeignFieldShapesIsStillSurveyed(t *testing.T) {
	root := t.TempDir()
	dir := filepath.Join(root, "audit-core")
	if err := os.MkdirAll(dir, 0o755); err != nil {
		t.Fatal(err)
	}
	body := "layer: engine\nrole: evidence\nemission_guarantee:\n  - id: chain-head-attestation\n"
	if err := os.WriteFile(filepath.Join(dir, "layer.yaml"), []byte(body), 0o644); err != nil {
		t.Fatal(err)
	}
	rows, _ := layer.SurveyDeclarations(root, []string{"audit-core"})
	if !rows[0].File.Found || rows[0].File.Canonical != "Engine" {
		t.Fatalf("audit-core's layer.yaml was dropped: %+v", rows[0].File)
	}
}