package api_test

import (
	"bytes"
	"context"
	"encoding/json"
	"net/http"
	"net/http/httptest"
	"testing"
	"time"

	"github.com/snip/backend/internal/adapter/memory"
	"github.com/snip/backend/internal/adapter/security"
	"github.com/snip/backend/internal/config"
	"github.com/snip/backend/internal/domain"
	"github.com/snip/backend/internal/httpx/api"
	"github.com/snip/backend/internal/service"
)

type harness struct {
	h     http.Handler
	token string
}

func newHarness(t *testing.T) *harness {
	t.Helper()
	repo := memory.NewLinkRepo()
	cache := memory.NewCache()
	users := memory.NewUserRepo()
	hasher := security.NewBcryptHasher()
	sessions := security.NewHMACSessions("test-secret")

	links := service.NewLinkService(repo, cache, hasher)
	auth := service.NewAuthService(nil, users, sessions)
	cfg := config.Config{PostLoginRedirect: "/dashboard"}

	user, err := users.Upsert(context.Background(), &domain.User{
		Email: "sam@example.com", Name: "Sam", Provider: "test", Subject: "s1",
	})
	if err != nil {
		t.Fatal(err)
	}
	token, _ := sessions.Issue(user.ID, time.Hour)

	return &harness{h: api.New(links, auth, sessions, cfg).Handler(), token: token}
}

func (h *harness) do(t *testing.T, method, path, body, token string) *httptest.ResponseRecorder {
	t.Helper()
	var r *http.Request
	if body != "" {
		r = httptest.NewRequest(method, path, bytes.NewBufferString(body))
	} else {
		r = httptest.NewRequest(method, path, nil)
	}
	if token != "" {
		r.AddCookie(&http.Cookie{Name: "snip_session", Value: token})
	}
	w := httptest.NewRecorder()
	h.h.ServeHTTP(w, r)
	return w
}

func decodeLink(t *testing.T, w *httptest.ResponseRecorder) map[string]any {
	t.Helper()
	var m map[string]any
	if err := json.Unmarshal(w.Body.Bytes(), &m); err != nil {
		t.Fatalf("bad json (%d): %s", w.Code, w.Body.String())
	}
	return m
}

func TestAnonCanCreateRandomButNotList(t *testing.T) {
	h := newHarness(t)

	w := h.do(t, http.MethodPost, "/api/v1/links", `{"longUrl":"acme.com/x","mode":"random"}`, "")
	if w.Code != http.StatusCreated {
		t.Fatalf("create: want 201, got %d: %s", w.Code, w.Body.String())
	}
	if code, _ := decodeLink(t, w)["code"].(string); code == "" {
		t.Fatal("expected a code")
	}

	if w := h.do(t, http.MethodGet, "/api/v1/links", "", ""); w.Code != http.StatusUnauthorized {
		t.Fatalf("anon list: want 401, got %d", w.Code)
	}
}

func TestCustomAndReservedAndConflict(t *testing.T) {
	h := newHarness(t)

	// reserved alias → 409
	if w := h.do(t, http.MethodPost, "/api/v1/links", `{"longUrl":"acme.com","mode":"custom","customAlias":"dashboard"}`, h.token); w.Code != http.StatusConflict {
		t.Fatalf("reserved: want 409, got %d", w.Code)
	}
	// valid custom → 201
	if w := h.do(t, http.MethodPost, "/api/v1/links", `{"longUrl":"acme.com","mode":"custom","customAlias":"promo"}`, h.token); w.Code != http.StatusCreated {
		t.Fatalf("custom: want 201, got %d: %s", w.Code, w.Body.String())
	}
	// duplicate → 409
	if w := h.do(t, http.MethodPost, "/api/v1/links", `{"longUrl":"acme.com","mode":"custom","customAlias":"promo"}`, h.token); w.Code != http.StatusConflict {
		t.Fatalf("dupe: want 409, got %d", w.Code)
	}
	// anon custom → 401
	if w := h.do(t, http.MethodPost, "/api/v1/links", `{"longUrl":"acme.com","mode":"custom","customAlias":"x9z"}`, ""); w.Code != http.StatusUnauthorized {
		t.Fatalf("anon custom: want 401, got %d", w.Code)
	}
}

func TestFullLifecycleWithPin(t *testing.T) {
	h := newHarness(t)

	// create
	w := h.do(t, http.MethodPost, "/api/v1/links", `{"longUrl":"acme.com/a","mode":"random"}`, h.token)
	id := decodeLink(t, w)["id"].(string)

	// list shows it
	w = h.do(t, http.MethodGet, "/api/v1/links", "", h.token)
	if w.Code != http.StatusOK {
		t.Fatalf("list: %d", w.Code)
	}
	if total := listTotal(t, w); total != 1 {
		t.Fatalf("want total 1, got %d", total)
	}

	// patch destination
	w = h.do(t, http.MethodPatch, "/api/v1/links/"+id, `{"longUrl":"acme.com/b"}`, h.token)
	if w.Code != http.StatusOK || decodeLink(t, w)["longUrl"] != "https://acme.com/b" {
		t.Fatalf("patch failed: %d %s", w.Code, w.Body.String())
	}

	// set pin
	w = h.do(t, http.MethodPut, "/api/v1/links/"+id+"/pin", `{"pin":"123456"}`, h.token)
	if w.Code != http.StatusOK || decodeLink(t, w)["hasPin"] != true {
		t.Fatalf("set pin failed: %d %s", w.Code, w.Body.String())
	}
	// bad pin → 400
	if w := h.do(t, http.MethodPut, "/api/v1/links/"+id+"/pin", `{"pin":"12"}`, h.token); w.Code != http.StatusBadRequest {
		t.Fatalf("bad pin: want 400, got %d", w.Code)
	}
	// remove pin
	w = h.do(t, http.MethodDelete, "/api/v1/links/"+id+"/pin", "", h.token)
	if w.Code != http.StatusOK || decodeLink(t, w)["hasPin"] != false {
		t.Fatalf("remove pin failed: %d", w.Code)
	}

	// delete
	if w := h.do(t, http.MethodDelete, "/api/v1/links/"+id, "", h.token); w.Code != http.StatusNoContent {
		t.Fatalf("delete: want 204, got %d", w.Code)
	}
	// gone from list
	w = h.do(t, http.MethodGet, "/api/v1/links", "", h.token)
	if total := listTotal(t, w); total != 0 {
		t.Fatalf("want 0 links after delete, got %d", total)
	}
}

func listTotal(t *testing.T, w *httptest.ResponseRecorder) int {
	t.Helper()
	var resp struct {
		Items []map[string]any `json:"items"`
		Total int              `json:"total"`
	}
	if err := json.Unmarshal(w.Body.Bytes(), &resp); err != nil {
		t.Fatalf("bad list json: %s", w.Body.String())
	}
	return resp.Total
}

func TestPatchForbiddenForOtherUser(t *testing.T) {
	h := newHarness(t)
	w := h.do(t, http.MethodPost, "/api/v1/links", `{"longUrl":"acme.com","mode":"random"}`, h.token)
	id := decodeLink(t, w)["id"].(string)

	other := security.NewHMACSessions("test-secret")
	otherToken, _ := other.Issue("someone-else", time.Hour)
	if w := h.do(t, http.MethodPatch, "/api/v1/links/"+id, `{"longUrl":"https://evil.com"}`, otherToken); w.Code != http.StatusForbidden {
		t.Fatalf("want 403 for non-owner, got %d", w.Code)
	}
}

func TestMeRequiresSession(t *testing.T) {
	h := newHarness(t)
	if w := h.do(t, http.MethodGet, "/api/v1/auth/me", "", ""); w.Code != http.StatusUnauthorized {
		t.Fatalf("me anon: want 401, got %d", w.Code)
	}
	w := h.do(t, http.MethodGet, "/api/v1/auth/me", "", h.token)
	if w.Code != http.StatusOK || decodeLink(t, w)["email"] != "sam@example.com" {
		t.Fatalf("me: %d %s", w.Code, w.Body.String())
	}
}

func TestHealthz(t *testing.T) {
	h := newHarness(t)
	if w := h.do(t, http.MethodGet, "/api/v1/healthz", "", ""); w.Code != http.StatusOK {
		t.Fatalf("healthz: %d", w.Code)
	}
}