package httpapi

import (
	"encoding/json"
	"io"
	"net/http"
	"net/http/httptest"
	"strings"
	"testing"

	"basicstack.de/proofedmesh/services/transparency-log/pkg/backend"
)

func fixtureEnvelope() backend.Envelope {
	return backend.Envelope{
		PayloadType: "application/vnd.in-toto+json",
		Payload:     "aGVsbG8",
		Signatures:  []backend.EnvelopeSignature{{KeyID: "k", Sig: "c2ln"}},
	}
}

func newServer(t *testing.T) *httptest.Server {
	t.Helper()
	s := &Server{Backend: backend.NewMemory()}
	return httptest.NewServer(s.Handler())
}

func TestSubmit_HappyPath_201(t *testing.T) {
	srv := newServer(t)
	defer srv.Close()
	env := fixtureEnvelope()
	ch, err := backend.EnvelopeContentHash(env)
	if err != nil {
		t.Fatalf("hash: %v", err)
	}
	body, _ := json.Marshal(submitRequest{Envelope: env, ContentHash: ch})
	resp, err := http.Post(srv.URL+"/api/v1/log/entries", "application/json", strings.NewReader(string(body)))
	if err != nil {
		t.Fatalf("post: %v", err)
	}
	defer resp.Body.Close()
	if resp.StatusCode != http.StatusCreated {
		raw, _ := io.ReadAll(resp.Body)
		t.Fatalf("want 201, got %d: %s", resp.StatusCode, raw)
	}
	var rct backend.Receipt
	if err := json.NewDecoder(resp.Body).Decode(&rct); err != nil {
		t.Fatalf("decode: %v", err)
	}
	if rct.ContentHash != ch {
		t.Errorf("content_hash echoed wrong: %q vs %q", rct.ContentHash, ch)
	}
	if rct.LogIndex != 0 {
		t.Errorf("log_index: %d", rct.LogIndex)
	}
	if rct.InclusionProof.TreeSize != 1 {
		t.Errorf("tree_size: %d", rct.InclusionProof.TreeSize)
	}
}

func TestSubmit_Idempotent_200_SameIndex(t *testing.T) {
	srv := newServer(t)
	defer srv.Close()
	env := fixtureEnvelope()
	ch, _ := backend.EnvelopeContentHash(env)
	body, _ := json.Marshal(submitRequest{Envelope: env, ContentHash: ch})

	// First call -> 201
	resp1, err := http.Post(srv.URL+"/api/v1/log/entries", "application/json", strings.NewReader(string(body)))
	if err != nil {
		t.Fatalf("post1: %v", err)
	}
	resp1.Body.Close()
	if resp1.StatusCode != http.StatusCreated {
		t.Fatalf("first status: %d", resp1.StatusCode)
	}

	// Second call -> 200
	resp2, err := http.Post(srv.URL+"/api/v1/log/entries", "application/json", strings.NewReader(string(body)))
	if err != nil {
		t.Fatalf("post2: %v", err)
	}
	defer resp2.Body.Close()
	if resp2.StatusCode != http.StatusOK {
		raw, _ := io.ReadAll(resp2.Body)
		t.Fatalf("idempotent repeat status: want 200, got %d, body=%s", resp2.StatusCode, raw)
	}
	var rct2 backend.Receipt
	if err := json.NewDecoder(resp2.Body).Decode(&rct2); err != nil {
		t.Fatalf("decode: %v", err)
	}
	if rct2.LogIndex != 0 {
		t.Errorf("idempotent log_index: want 0, got %d", rct2.LogIndex)
	}
}

func TestSubmit_ContentHashMismatch_409(t *testing.T) {
	srv := newServer(t)
	defer srv.Close()
	env := fixtureEnvelope()
	bogus := "sha256:" + strings.Repeat("0", 64)
	body, _ := json.Marshal(submitRequest{Envelope: env, ContentHash: bogus})
	resp, err := http.Post(srv.URL+"/api/v1/log/entries", "application/json", strings.NewReader(string(body)))
	if err != nil {
		t.Fatalf("post: %v", err)
	}
	defer resp.Body.Close()
	if resp.StatusCode != http.StatusConflict {
		raw, _ := io.ReadAll(resp.Body)
		t.Fatalf("want 409, got %d: %s", resp.StatusCode, raw)
	}
}

func TestSubmit_RejectsMissingContentHash(t *testing.T) {
	srv := newServer(t)
	defer srv.Close()
	body := `{"envelope":{"payloadType":"application/vnd.in-toto+json","payload":"aGVsbG8","signatures":[]}}`
	resp, err := http.Post(srv.URL+"/api/v1/log/entries", "application/json", strings.NewReader(body))
	if err != nil {
		t.Fatalf("post: %v", err)
	}
	defer resp.Body.Close()
	if resp.StatusCode != http.StatusBadRequest {
		t.Fatalf("want 400, got %d", resp.StatusCode)
	}
}

func TestSubmit_UnknownRoute_404(t *testing.T) {
	srv := newServer(t)
	defer srv.Close()
	resp, err := http.Post(srv.URL+"/api/v1/log/other", "application/json", strings.NewReader("{}"))
	if err != nil {
		t.Fatalf("post: %v", err)
	}
	defer resp.Body.Close()
	if resp.StatusCode != http.StatusNotFound {
		t.Fatalf("want 404, got %d", resp.StatusCode)
	}
}

func TestSubmit_TrillianStub_Returns503(t *testing.T) {
	srv := httptest.NewServer((&Server{Backend: backend.Trillian{}}).Handler())
	defer srv.Close()
	env := fixtureEnvelope()
	ch, _ := backend.EnvelopeContentHash(env)
	body, _ := json.Marshal(submitRequest{Envelope: env, ContentHash: ch})
	resp, err := http.Post(srv.URL+"/api/v1/log/entries", "application/json", strings.NewReader(string(body)))
	if err != nil {
		t.Fatalf("post: %v", err)
	}
	defer resp.Body.Close()
	if resp.StatusCode != http.StatusServiceUnavailable {
		raw, _ := io.ReadAll(resp.Body)
		t.Fatalf("trillian stub want 503, got %d: %s", resp.StatusCode, raw)
	}
}