package approvalfact

import (
	"bytes"
	"encoding/json"
	"os"
	"strings"
	"testing"
	"time"
)

type vectors struct {
	Native []struct {
		Binding   json.RawMessage `json:"binding"`
		Canonical string          `json:"canonical_binding_utf8"`
		Digest    string          `json:"native_digest"`
	} `json:"native_binding_vectors"`
	Claims []struct {
		Name      string          `json:"name"`
		Now       time.Time       `json:"validation_time"`
		Submitted json.RawMessage `json:"submitted_claim"`
		Observed  json.RawMessage `json:"observed_claim"`
		Binding   json.RawMessage `json:"expected_binding"`
		PDP       string          `json:"expected_pdp_digest"`
		Accept    bool            `json:"expected_accept"`
	} `json:"claim_cases"`
	Transport []struct {
		Name string `json:"name"`
		Body string `json:"body_utf8"`
	} `json:"transport_cases"`
}

func load(t *testing.T) vectors {
	t.Helper()
	raw, e := os.ReadFile("testdata/owner-vectors.json")
	if e != nil {
		t.Fatal(e)
	}
	var v vectors
	if e = json.Unmarshal(raw, &v); e != nil {
		t.Fatal(e)
	}
	return v
}

func TestProducerCanonicalVectors(t *testing.T) {
	for _, v := range load(t).Native {
		t.Run(v.Digest, func(t *testing.T) {
			raw, d, e := CanonicalBinding(v.Binding)
			if e != nil || string(raw) != v.Canonical || d != v.Digest {
				t.Fatalf("producer parity: %q %s %v, want %q %s", raw, d, e, v.Canonical, v.Digest)
			}
		})
	}
}

func TestProducerClaimVectors(t *testing.T) {
	for _, v := range load(t).Claims {
		t.Run(v.Name, func(t *testing.T) {
			var id struct {
				ID string `json:"approval_id"`
			}
			if e := json.Unmarshal(v.Submitted, &id); e != nil {
				t.Fatal(e)
			}
			expected := Expected{id.ID, v.Binding, v.PDP}
			old, e1 := ValidateClaim(v.Submitted, expected, v.Now)
			fresh, e2 := ValidateClaim(v.Observed, expected, v.Now)
			accepted := e1 == nil && e2 == nil && MatchObserved(old, fresh) == nil
			if accepted != v.Accept {
				t.Fatalf("accepted=%v want=%v original=%v observed=%v", accepted, v.Accept, e1, e2)
			}
			if accepted {
				raw := old.RawJSON()
				if !bytes.Equal(raw, v.Submitted) {
					t.Fatal("original bytes changed")
				}
				raw[0] = 'x'
				if old.RawJSON()[0] != '{' {
					t.Fatal("mutable fact storage")
				}
				if !old.Deadline().Before(fresh.Deadline()) {
					t.Fatal("refresh must not extend original deadline")
				}
			}
		})
	}
}

func TestStrictJSONRefusals(t *testing.T) {
	for _, raw := range []string{`{"a":1,"a":2}`, `{"a":{"x":1,"x":2}}`, `{"a":NaN}`, `{"a":1e999}`, `{"a":"\ud800"}`, `{"a":"\udfff"}`, `{"a":"\ud800x"}`, `{"a":1} {}`, `{"a":"` + string([]byte{0xff}) + `"}`, strings.Repeat("[", 130) + strings.Repeat("]", 130), strings.Repeat(" ", MaxJSONBytes+1)} {
		if _, e := DecodeJSON([]byte(raw)); e == nil {
			t.Fatalf("accepted malformed JSON %.80q", raw)
		}
	}
}

func TestUnicodeAndControlEncoding(t *testing.T) {
	for _, raw := range []string{`{"v":"\ud83d\ude00"}`, `{"v":"escaped \\\" quote"}`, `{"v":"\u0000\b\f\n\r\t"}`} {
		if _, e := DecodeJSON([]byte(raw)); e != nil {
			t.Fatalf("refused valid Unicode %q", raw)
		}
	}
}

func TestGoldenDuplicateAndNonfiniteBodies(t *testing.T) {
	for _, v := range load(t).Transport {
		if v.Name == "duplicate_valid_now" || v.Name == "nonfinite_json" {
			if _, e := DecodeJSON([]byte(v.Body)); e == nil {
				t.Fatal(v.Name)
			}
		}
	}
}

func TestInvalidExpectedAndZeroFacts(t *testing.T) {
	v := load(t).Claims[0]
	if _, e := ValidateClaim(v.Submitted, Expected{}, v.Now); e == nil {
		t.Fatal("missing expected act accepted")
	}
	if MatchObserved(Fact{}, Fact{}) == nil {
		t.Fatal("zero facts accepted")
	}
	expected := Expected{"11111111-1111-4111-8111-111111111111", v.Binding, v.PDP}
	a, e := ValidateClaim(v.Submitted, expected, v.Now)
	if e != nil {
		t.Fatal(e)
	}
	b, e := ValidateClaim(v.Observed, expected, v.Now.Add(time.Second))
	if e != nil {
		t.Fatal(e)
	}
	if MatchObserved(a, b) == nil {
		t.Fatal("different validation instants accepted")
	}
}

func TestTimestampPrecisionAndOffsetRefusals(t *testing.T) {
	for _, value := range []string{"2026-08-29T12:00:00,1Z", "2026-08-29T12:00:00+24:00", "2026-08-29T12:00:00+00:60", "2026-08-29T12:00:00.0000000001Z", "2026-08-29T12:00:00"} {
		if _, err := stamp(value); err == nil {
			t.Fatalf("accepted unsupported timestamp %q", value)
		}
	}
}