package api_test

import (
	"bufio"
	"bytes"
	"encoding/json"
	"io"
	"io/fs"
	"net/http"
	"net/http/httptest"
	"strings"
	"testing"
	"testing/fstest"
	"time"

	"github.com/lgcosta/notas-online/internal/api"
	"github.com/lgcosta/notas-online/internal/store"
)

const testToken = "s3cr3t-token"

func newTestServer(t *testing.T) *httptest.Server {
	t.Helper()
	st, err := store.New(t.TempDir())
	if err != nil {
		t.Fatal(err)
	}
	webFS := fs.FS(fstest.MapFS{"index.html": &fstest.MapFile{Data: []byte("<html>MOUSEPAD-SHELL</html>")}})
	srv := httptest.NewServer(api.New(st, testToken, webFS).Handler())
	t.Cleanup(srv.Close)
	return srv
}

func do(t *testing.T, srv *httptest.Server, method, path, body, bearer, cookie string) *http.Response {
	t.Helper()
	var rdr io.Reader
	if body != "" {
		rdr = strings.NewReader(body)
	}
	req, err := http.NewRequest(method, srv.URL+path, rdr)
	if err != nil {
		t.Fatal(err)
	}
	if bearer != "" {
		req.Header.Set("Authorization", "Bearer "+bearer)
	}
	if cookie != "" {
		req.Header.Add("Cookie", cookie)
	}
	resp, err := srv.Client().Do(req)
	if err != nil {
		t.Fatal(err)
	}
	return resp
}

func decode(t *testing.T, resp *http.Response, v any) {
	t.Helper()
	defer resp.Body.Close()
	if err := json.NewDecoder(resp.Body).Decode(v); err != nil {
		t.Fatalf("decodificando resposta %s %s: %v", resp.Status, resp.Request.URL.Path, err)
	}
}

type noteView struct {
	ID         string   `json:"id"`
	Title      string   `json:"title"`
	Format     string   `json:"format"`
	Categories []string `json:"categories"`
	Tags       []string `json:"tags"`
	Hash       string   `json:"hash"`
	Content    string   `json:"content"`
}

func TestAuthRequiredAndLoginFlow(t *testing.T) {
	srv := newTestServer(t)

	// Sem token: API bloqueia.
	if resp := do(t, srv, "GET", "/api/notes", "", "", ""); resp.StatusCode != http.StatusUnauthorized {
		t.Fatalf("esperava 401 sem token, obtive %s", resp.Status)
	}
	resp := do(t, srv, "GET", "/api/notes", "", "token-errado", "")
	if resp.StatusCode != http.StatusUnauthorized {
		t.Fatalf("bearer errado deveria dar 401, obtive %s", resp.Status)
	}

	// Login errado.
	resp = do(t, srv, "POST", "/api/login", `{"token":"nope"}`, "", "")
	if resp.StatusCode != http.StatusUnauthorized {
		t.Fatalf("login errado: %s", resp.Status)
	}

	// Login correto: cookie HttpOnly com ID DE SESSÃO opaco (nunca o token mestre).
	resp = do(t, srv, "POST", "/api/login", `{"token":"`+testToken+`"}`, "", "")
	if resp.StatusCode != http.StatusOK {
		t.Fatalf("login: %s", resp.Status)
	}
	sc := resp.Header.Get("Set-Cookie")
	if !strings.HasPrefix(sc, "notas_token=") || !strings.Contains(sc, "HttpOnly") ||
		strings.Contains(sc, "Max-Age=0") {
		t.Errorf("Set-Cookie inadequado: %q", sc)
	}
	cookieValue := strings.SplitN(strings.TrimPrefix(sc, "notas_token="), ";", 2)[0]
	if cookieValue == testToken || strings.Contains(sc, testToken) {
		t.Errorf("cookie não deveria carregar o token mestre: %q", sc)
	}
	if len(cookieValue) != 64 {
		t.Errorf("id de sessão deveria ter 64 hex chars (32 bytes), tem %d", len(cookieValue))
	}

	// /api/me com o cookie.
	resp = do(t, srv, "GET", "/api/me", "", "", "notas_token="+cookieValue)
	if resp.StatusCode != http.StatusOK {
		t.Fatalf("/api/me com cookie: %s", resp.Status)
	}

	// Logout limpa o cookie.
	resp = do(t, srv, "POST", "/api/logout", "", "", "notas_token="+cookieValue)
	resp.Body.Close()
	sc = resp.Header.Get("Set-Cookie")
	if !strings.Contains(sc, "Max-Age=0") && !strings.Contains(sc, "Expires=Thu, 01 Jan 1970") {
		t.Errorf("logout deveria expirar o cookie: %q", sc)
	}

	// Index é público e servido do FS embutido.
	resp = do(t, srv, "GET", "/", "", "", "")
	var buf bytes.Buffer
	_, _ = buf.ReadFrom(resp.Body)
	resp.Body.Close()
	if !strings.Contains(buf.String(), "MOUSEPAD-SHELL") {
		t.Errorf("index não servido: %q", buf.String())
	}
}

func TestNoteLifecycleWithHistoryAndRestore(t *testing.T) {
	srv := newTestServer(t)
	call := func(method, path, body string) *http.Response {
		return do(t, srv, method, path, body, testToken, "")
	}

	// Criar uma categoria raiz e uma filha para vincular à nota.
	resp := call("POST", "/api/categories", `{"name":"devops","parent":""}`)
	if resp.StatusCode != http.StatusCreated {
		t.Fatalf("create category: %s", resp.Status)
	}
	var cat struct {
		ID   string `json:"id"`
		Name string `json:"name"`
	}
	decode(t, resp, &cat)

	// Criar nota em múltiplas categorias.
	resp = call("POST", "/api/notes",
		`{"title":"Servidor","format":"md","categories":["`+cat.ID+`"],"content":"# Notas\n\n#linux #systemd","author":"lg","message":""}`)
	if resp.StatusCode != http.StatusCreated {
		t.Fatalf("create: %s", resp.Status)
	}
	var created noteView
	decode(t, resp, &created)
	if created.ID == "" || len(created.Tags) != 2 || len(created.Categories) != 1 {
		t.Fatalf("payload criado: %+v", created)
	}
	id := created.ID

	// Listar com filtro de tag.
	resp = call("GET", "/api/notes?tag=linux", "")
	var list []noteView
	decode(t, resp, &list)
	if len(list) != 1 || list[0].Content != "" { // listagem não carrega conteúdo
		t.Fatalf("list: %+v", list)
	}

	// Ler completo.
	resp = call("GET", "/api/notes/"+id, "")
	var got noteView
	decode(t, resp, &got)
	if !strings.Contains(got.Content, "#systemd") {
		t.Fatalf("get: %+v", got)
	}

	// Atualizar: nova revisão.
	resp = call("PUT", "/api/notes/"+id,
		`{"title":"Servidor","format":"md","categories":["`+cat.ID+`"],"content":"# Notas\n\n#linux","author":"lg","message":"removi systemd"}`)
	var updated noteView
	decode(t, resp, &updated)
	if updated.Hash == created.Hash {
		t.Fatal("hash não mudou após edição de conteúdo")
	}

	// Histórico: mais recente primeiro, com parent e mensagem.
	resp = call("GET", "/api/notes/"+id+"/revisions", "")
	var revs []store.Revision
	decode(t, resp, &revs)
	if len(revs) != 2 || revs[0].Message != "removi systemd" || revs[0].Parent != created.Hash {
		t.Fatalf("revisões: %+v", revs)
	}

	// Diff da revisão atual.
	resp = call("GET", "/api/notes/"+id+"/revisions/"+revs[0].Hash+"/diff", "")
	var dv struct {
		Diff    string `json:"diff"`
		Added   int    `json:"added"`
		Removed int    `json:"removed"`
	}
	decode(t, resp, &dv)
	if !strings.Contains(dv.Diff, "-#linux #systemd") || !strings.Contains(dv.Diff, "+#linux") {
		t.Fatalf("diff: %q", dv.Diff)
	}
	if dv.Added != 1 || dv.Removed != 1 {
		t.Fatalf("stats do diff: +%d -%d", dv.Added, dv.Removed)
	}

	// GET de revisão específica (conteúdo + metadados).
	resp = call("GET", "/api/notes/"+id+"/revisions/"+created.Hash, "")
	if resp.StatusCode != http.StatusOK {
		t.Fatalf("get revision: %s", resp.Status)
	}
	var rc struct {
		Hash    string `json:"hash"`
		Content string `json:"content"`
	}
	decode(t, resp, &rc)
	if rc.Hash != created.Hash || !strings.Contains(rc.Content, "#systemd") {
		t.Fatalf("revisão: %+v", rc)
	}
	// Hash malformado → 404.
	resp = call("GET", "/api/notes/"+id+"/revisions/xyz", "")
	if resp.StatusCode != http.StatusNotFound {
		t.Fatalf("hash inválido: esperava 404, obtive %s", resp.Status)
	}
	resp.Body.Close()

	resp = call("POST", "/api/notes/"+id+"/revisions/"+created.Hash+"/restore", `{"author":"lg"}`)
	if resp.StatusCode != http.StatusOK {
		t.Fatalf("restore: %s", resp.Status)
	}
	var restored noteView
	decode(t, resp, &restored)
	if !strings.Contains(restored.Content, "#systemd") {
		t.Fatalf("restore não trouxe conteúdo antigo: %+v", restored)
	}

	// Restaurar de novo → 409.
	resp = call("POST", "/api/notes/"+id+"/revisions/"+created.Hash+"/restore", `{"author":"lg"}`)
	if resp.StatusCode != http.StatusConflict {
		t.Fatalf("esperava 409, obtive %s", resp.Status)
	}
	resp.Body.Close()

	// Download bruto com Content-Disposition.
	resp = call("GET", "/api/notes/"+id+"/raw", "")
	if cd := resp.Header.Get("Content-Disposition"); !strings.Contains(cd, `attachment; filename="Servidor.md"`) {
		t.Errorf("Content-Disposition: %q", cd)
	}
	resp.Body.Close()

	// Deletar → 204, e GET passa a 404.
	resp = call("DELETE", "/api/notes/"+id, "")
	if resp.StatusCode != http.StatusNoContent {
		t.Fatalf("delete: %s", resp.Status)
	}
	resp = call("GET", "/api/notes/"+id, "")
	if resp.StatusCode != http.StatusNotFound {
		t.Fatalf("get pós-delete: %s", resp.Status)
	}
}

func TestRenderMarkdownIsSafe(t *testing.T) {
	srv := newTestServer(t)
	resp := do(t, srv, "POST", "/api/render",
		`{"content":"**negrito** <script>alert(1)</script>\nlinha1\nlinha2","format":"md"}`, testToken, "")
	var out struct {
		HTML string `json:"html"`
	}
	decode(t, resp, &out)
	if !strings.Contains(out.HTML, "<strong>negrito</strong>") {
		t.Errorf("markdown não renderizado: %q", out.HTML)
	}
	if strings.Contains(out.HTML, "<script>") {
		t.Errorf("HTML cru deveria ser escapado: %q", out.HTML)
	}
	if !strings.Contains(out.HTML, "<br") {
		t.Errorf("quebra de linha simples deveria virar <br>: %q", out.HTML)
	}

	// html não é renderizado no servidor.
	resp = do(t, srv, "POST", "/api/render", `{"content":"<b>x</b>","format":"html"}`, testToken, "")
	if resp.StatusCode != http.StatusBadRequest {
		t.Errorf("formato html deveria retornar 400, obtive %s", resp.Status)
	}
	resp.Body.Close()
}

func TestCategoryCRUDViaAPI(t *testing.T) {
	srv := newTestServer(t)
	call := func(method, path, body string) *http.Response {
		return do(t, srv, method, path, body, testToken, "")
	}

	resp := call("POST", "/api/categories", `{"name":"infra","parent":""}`)
	var infra struct{ ID string }
	decode(t, resp, &infra)
	resp = call("POST", "/api/categories", `{"name":"linux","parent":"`+infra.ID+`"}`)
	var linux struct{ ID string }
	decode(t, resp, &linux)

	// duplicata entre irmãos → 400
	resp = call("POST", "/api/categories", `{"name":"Infra","parent":""}`)
	if resp.StatusCode != http.StatusBadRequest {
		t.Fatalf("duplicata: %s", resp.Status)
	}
	resp.Body.Close()

	// nota na subcategoria
	resp = call("POST", "/api/notes", `{"title":"Kernel","format":"txt","categories":["`+linux.ID+`"],"content":"x","author":"","message":""}`)
	var note noteView
	decode(t, resp, &note)

	// filtro recursivo pela raiz (padrão) → 1 nota; não-recursivo → 0
	resp = call("GET", "/api/notes?category="+infra.ID, "")
	var rec []noteView
	decode(t, resp, &rec)
	if len(rec) != 1 {
		t.Fatalf("recursivo: %+v", rec)
	}
	resp = call("GET", "/api/notes?category="+infra.ID+"&recursive=0", "")
	var nonrec []noteView
	decode(t, resp, &nonrec)
	if len(nonrec) != 0 {
		t.Fatalf("não-recursivo: %+v", nonrec)
	}

	// ciclo: mover infra para dentro de linux → 400
	resp = call("PUT", "/api/categories/"+infra.ID, `{"name":"","parent":"`+linux.ID+`"}`)
	if resp.StatusCode != http.StatusBadRequest {
		t.Fatalf("ciclo deveria dar 400, obtive %s", resp.Status)
	}
	resp.Body.Close()

	// excluir raiz remove subtree e limpa a nota
	resp = call("DELETE", "/api/categories/"+infra.ID, "")
	if resp.StatusCode != http.StatusNoContent {
		t.Fatalf("delete: %s", resp.Status)
	}
	resp = call("GET", "/api/notes/"+note.ID, "")
	decode(t, resp, &note)
	if len(note.Categories) != 0 {
		t.Errorf("nota deveria ficar órfã: %+v", note.Categories)
	}
	resp = call("GET", "/api/categories", "")
	var cats []map[string]any
	decode(t, resp, &cats)
	if len(cats) != 0 {
		t.Errorf("árvore deveria estar vazia: %+v", cats)
	}

	// categoria inexistente em nota → 400
	resp = call("POST", "/api/notes", `{"title":"x","format":"txt","categories":["zzzzzzzzzzzz"],"content":"", "author":"","message":""}`)
	if resp.StatusCode != http.StatusBadRequest {
		t.Fatalf("categoria fantasma: %s", resp.Status)
	}
	resp.Body.Close()
}

func TestSaveConflictViaAPI(t *testing.T) {
	srv := newTestServer(t)
	call := func(method, path, body string) *http.Response {
		return do(t, srv, method, path, body, testToken, "")
	}
	resp := call("POST", "/api/notes", `{"title":"Sync","format":"txt","categories":[],"content":"v1","author":"","message":""}`)
	var created noteView
	decode(t, resp, &created)

	// dispositivo B salva primeiro (sem base_hash = força)
	resp = call("PUT", "/api/notes/"+created.ID,
		`{"title":"Sync","format":"txt","categories":[],"content":"v2-B","author":"B","message":"B ganhou"}`)
	if resp.StatusCode != http.StatusOK {
		t.Fatalf("save B: %s", resp.Status)
	}
	var afterB noteView
	decode(t, resp, &afterB)

	// dispositivo A salva com base antiga → 409 + server_hash
	resp = call("PUT", "/api/notes/"+created.ID,
		`{"title":"Sync","format":"txt","categories":[],"content":"v2-A","author":"A","message":"A atrasado","base_hash":"`+created.Hash+`"}`)
	if resp.StatusCode != http.StatusConflict {
		t.Fatalf("esperava 409, obtive %s", resp.Status)
	}
	var conflict struct {
		Error      string `json:"error"`
		ServerHash string `json:"server_hash"`
	}
	decode(t, resp, &conflict)
	if conflict.ServerHash != afterB.Hash {
		t.Errorf("409 deveria trazer o hash atual: %q != %q", conflict.ServerHash, afterB.Hash)
	}

	// A resolve: força sem base_hash
	resp = call("PUT", "/api/notes/"+created.ID,
		`{"title":"Sync","format":"txt","categories":[],"content":"v3-A forçado","author":"A","message":"force"}`)
	if resp.StatusCode != http.StatusOK {
		t.Fatalf("force: %s", resp.Status)
	}
	resp.Body.Close()
}

func TestPresenceAndSSEEvents(t *testing.T) {
	srv := newTestServer(t)
	call := func(method, path, body string) *http.Response {
		return do(t, srv, method, path, body, testToken, "")
	}

	// abre o stream SSE
	req, err := http.NewRequest("GET", srv.URL+"/api/events?session=s1", nil)
	if err != nil {
		t.Fatal(err)
	}
	req.Header.Set("Authorization", "Bearer "+testToken)
	streamResp, err := srv.Client().Do(req)
	if err != nil {
		t.Fatal(err)
	}
	defer streamResp.Body.Close()
	if ct := streamResp.Header.Get("Content-Type"); ct != "text/event-stream" {
		t.Fatalf("content-type SSE: %q", ct)
	}
	sc := bufio.NewScanner(streamResp.Body)

	readEvent := func(contains string) string {
		t.Helper()
		deadline := time.Now().Add(5 * time.Second)
		for sc.Scan() && time.Now().Before(deadline) {
			line := sc.Text()
			if strings.HasPrefix(line, "data: ") && strings.Contains(line, contains) {
				return line
			}
		}
		if err := sc.Err(); err != nil {
			t.Fatalf("scanner SSE: %v", err)
		}
		t.Fatalf("evento contendo %q não chegou", contains)
		return ""
	}

	// hello inicial com snapshot de presença
	readEvent(`"type":"hello"`)

	// heartbeat de presença → broadcast presence com s2
	resp := call("POST", "/api/presence", `{"session":"s2","notes":["nota1"]}`)
	if resp.StatusCode != http.StatusNoContent {
		t.Fatalf("presence: %s", resp.Status)
	}
	readEvent(`"type":"presence"`)

	// presença sem session → 400
	resp = call("POST", "/api/presence", `{"notes":[]}`)
	if resp.StatusCode != http.StatusBadRequest {
		t.Fatalf("presence sem session: %s", resp.Status)
	}
	resp.Body.Close()

	// criar nota com session → evento saved para os ouvintes
	resp = call("POST", "/api/notes", `{"title":"E","format":"txt","categories":[],"content":"x","author":"","message":"","session":"s3"}`)
	if resp.StatusCode != http.StatusCreated {
		t.Fatalf("create: %s", resp.Status)
	}
	var created noteView
	decode(t, resp, &created)
	ev := readEvent(`"type":"saved"`)
	if !strings.Contains(ev, `"session":"s3"`) || !strings.Contains(ev, created.ID) {
		t.Errorf("evento saved incompleto: %s", ev)
	}

	// SSE sem token → 401
	resp = do(t, srv, "GET", "/api/events", "", "", "")
	if resp.StatusCode != http.StatusUnauthorized {
		t.Fatalf("SSE sem auth: %s", resp.Status)
	}
	resp.Body.Close()
}

func TestInvalidPayloads(t *testing.T) {
	srv := newTestServer(t)
	resp := do(t, srv, "POST", "/api/notes", `{"format":"rtf","content":"x"}`, testToken, "")
	if resp.StatusCode != http.StatusBadRequest {
		t.Fatalf("formato inválido: %s", resp.Status)
	}
	resp.Body.Close()
	resp = do(t, srv, "POST", "/api/notes", `{"token":"extra"}`, testToken, "")
	if resp.StatusCode != http.StatusBadRequest {
		t.Fatalf("campo desconhecido deveria falhar (DisallowUnknownFields): %s", resp.Status)
	}
	resp.Body.Close()
	resp = do(t, srv, "GET", "/api/notes/z0zzzzzzzzzz/revisions", "", testToken, "")
	if resp.StatusCode != http.StatusNotFound {
		t.Fatalf("nota inexistente: %s", resp.Status)
	}
	resp.Body.Close()
}

func TestLoginRateLimitPerIP(t *testing.T) {
	srv := newTestServer(t)
	for i := 0; i < 5; i++ {
		resp := do(t, srv, "POST", "/api/login", `{"token":"errada"}`, "", "")
		resp.Body.Close()
		if resp.StatusCode != http.StatusUnauthorized {
			t.Fatalf("tentativa %d: esperava 401, obtive %s", i+1, resp.Status)
		}
	}
	// 6ª tentativa errada: bloqueada por IP
	resp := do(t, srv, "POST", "/api/login", `{"token":"errada"}`, "", "")
	resp.Body.Close()
	if resp.StatusCode != http.StatusTooManyRequests {
		t.Fatalf("esperava 429 após 5 falhas, obtive %s", resp.Status)
	}
	// bloqueio vale até para o token CORRETO (o IP está penalizado)
	resp = do(t, srv, "POST", "/api/login", `{"token":"`+testToken+`"}`, "", "")
	resp.Body.Close()
	if resp.StatusCode != http.StatusTooManyRequests {
		t.Fatalf("esperava 429 mesmo com token correto, obtive %s", resp.Status)
	}
}

func TestSessionRevokedOnLogoutAndBadSessionRejected(t *testing.T) {
	srv := newTestServer(t)
	resp := do(t, srv, "POST", "/api/login", `{"token":"`+testToken+`"}`, "", "")
	sc := resp.Header.Get("Set-Cookie")
	resp.Body.Close()
	sid := strings.SplitN(strings.TrimPrefix(sc, "notas_token="), ";", 2)[0]

	// sessão válida autentica
	resp = do(t, srv, "GET", "/api/me", "", "", "notas_token="+sid)
	resp.Body.Close()
	if resp.StatusCode != http.StatusOK {
		t.Fatalf("sessão válida: %s", resp.Status)
	}
	// token mestre cru NO cookie não vale mais (cookie = só id de sessão)
	resp = do(t, srv, "GET", "/api/me", "", "", "notas_token="+testToken)
	resp.Body.Close()
	if resp.StatusCode != http.StatusUnauthorized {
		t.Fatalf("token mestre no cookie deveria ser rejeitado, obtive %s", resp.Status)
	}
	// token mestre via Bearer continua valendo (scripts/CLI)
	resp = do(t, srv, "GET", "/api/me", "", testToken, "")
	resp.Body.Close()
	if resp.StatusCode != http.StatusOK {
		t.Fatalf("bearer com token mestre: %s", resp.Status)
	}
	// logout revoga a sessão
	resp = do(t, srv, "POST", "/api/logout", "", "", "notas_token="+sid)
	resp.Body.Close()
	resp = do(t, srv, "GET", "/api/me", "", "", "notas_token="+sid)
	resp.Body.Close()
	if resp.StatusCode != http.StatusUnauthorized {
		t.Fatalf("sessão após logout deveria estar revogada, obtive %s", resp.Status)
	}
}

func TestRenderRejectsOversizeInput(t *testing.T) {
	srv := newTestServer(t)
	big := strings.Repeat("x", 512<<10+1)
	body := `{"content":"` + big + `","format":"md"}`
	resp := do(t, srv, "POST", "/api/render", body, testToken, "")
	resp.Body.Close()
	if resp.StatusCode != http.StatusRequestEntityTooLarge {
		t.Fatalf("esperava 413 em render >512KiB, obtive %s", resp.Status)
	}
}