package web

import (
	"net/http"
	"net/http/httptest"
	"net/url"
	"strings"
	"testing"
	"time"

	"donniemarko/internal/note"
	"donniemarko/internal/render"
	"donniemarko/internal/service"
	"donniemarko/internal/storage"
)

type testEnv struct {
	handler *Handler
	storage *storage.NoteStorage
}

func newTestEnv(t *testing.T) *testEnv {
	t.Helper()

	ns := storage.NewNoteStorage()

	notes := []*note.Note{
		{
			ID:        "a1",
			Title:     "Alpha",
			Content:   "# Alpha\ncontent",
			UpdatedAt: time.Date(2025, 12, 31, 10, 0, 0, 0, time.UTC),
		},
		{
			ID:        "b2",
			Title:     "Beta",
			Content:   "# Beta\nRust tips",
			UpdatedAt: time.Date(2026, 1, 1, 10, 0, 0, 0, time.UTC),
		},
		{
			ID:        "z9",
			Title:     "Zulu",
			Content:   "# Zulu\nRust book",
			UpdatedAt: time.Date(2026, 1, 2, 10, 0, 0, 0, time.UTC),
		},
	}

	for _, n := range notes {
		if err := ns.Create(n); err != nil {
			t.Fatalf("create note: %v", err)
		}
	}

	svc := service.NewNoteService()
	svc.SetStorage(ns)

	tm := render.NewTemplateManager("templates")
	handler := NewHandler(svc, tm)

	return &testEnv{
		handler: handler,
		storage: ns,
	}
}

func assertOrder(t *testing.T, body string, want []string) {
	t.Helper()

	prev := -1
	for _, title := range want {
		idx := strings.Index(body, title)
		if idx == -1 {
			t.Fatalf("expected to find %q in response body", title)
		}
		if idx <= prev {
			t.Fatalf("expected %q to appear after previous title", title)
		}
		prev = idx
	}
}

func noteMarker(id string) string {
	return `data-hash="` + id + `"`
}

func TestHandlerRoot_DefaultSortRecent(t *testing.T) {
	env := newTestEnv(t)

	req := httptest.NewRequest(http.MethodGet, "/", nil)
	rec := httptest.NewRecorder()

	env.handler.ServeHTTP(rec, req)

	if rec.Code != http.StatusOK {
		t.Fatalf("expected status 200, got %d", rec.Code)
	}

	if ct := rec.Header().Get("Content-Type"); ct != "text/html; charset=utf-8" {
		t.Fatalf("expected content-type text/html; charset=utf-8, got %q", ct)
	}

	body := rec.Body.String()
	assertOrder(t, body, []string{noteMarker("z9"), noteMarker("b2"), noteMarker("a1")})
}

func TestHandlerRoot_SortAlpha(t *testing.T) {
	env := newTestEnv(t)

	req := httptest.NewRequest(http.MethodGet, "/?sort=alpha", nil)
	rec := httptest.NewRecorder()

	env.handler.ServeHTTP(rec, req)

	if rec.Code != http.StatusOK {
		t.Fatalf("expected status 200, got %d", rec.Code)
	}

	body := rec.Body.String()
	assertOrder(t, body, []string{noteMarker("a1"), noteMarker("b2"), noteMarker("z9")})
}

func TestHandlerRoot_Search(t *testing.T) {
	env := newTestEnv(t)

	req := httptest.NewRequest(http.MethodGet, "/?search=rust&sort=alpha", nil)
	rec := httptest.NewRecorder()

	env.handler.ServeHTTP(rec, req)

	if rec.Code != http.StatusOK {
		t.Fatalf("expected status 200, got %d", rec.Code)
	}

	body := rec.Body.String()
	if !strings.Contains(body, "Matching results for query 'rust'") {
		t.Fatalf("expected search header to be rendered")
	}

	if strings.Contains(body, `data-hash="a1"`) {
		t.Fatalf("expected non-matching note to be excluded")
	}

	assertOrder(t, body, []string{noteMarker("b2"), noteMarker("z9")})
}

func TestHandlerNotes_Success(t *testing.T) {
	env := newTestEnv(t)

	req := httptest.NewRequest(http.MethodGet, "/notes/b2", nil)
	rec := httptest.NewRecorder()

	env.handler.ServeHTTP(rec, req)

	if rec.Code != http.StatusOK {
		t.Fatalf("expected status 200, got %d", rec.Code)
	}

	body := rec.Body.String()
	if !strings.Contains(body, "<h1>Beta</h1>") {
		t.Fatalf("expected rendered markdown for note content")
	}
	if !strings.Contains(body, `class="active-note"`) {
		t.Fatalf("expected active note class in list")
	}
	if !strings.Contains(body, `data-hash="b2"`) {
		t.Fatalf("expected active note hash in list")
	}
}

func TestHandlerNotes_NotFound(t *testing.T) {
	env := newTestEnv(t)

	req := httptest.NewRequest(http.MethodGet, "/notes/missing", nil)
	rec := httptest.NewRecorder()

	env.handler.ServeHTTP(rec, req)

	if rec.Code != http.StatusNotFound {
		t.Fatalf("expected status 404, got %d", rec.Code)
	}

	if !strings.Contains(rec.Body.String(), "Note not found") {
		t.Fatalf("expected not found message")
	}
}

func TestHandler_NotFoundPath(t *testing.T) {
	env := newTestEnv(t)

	req := httptest.NewRequest(http.MethodGet, "/nope", nil)
	rec := httptest.NewRecorder()

	env.handler.ServeHTTP(rec, req)

	if rec.Code != http.StatusNotFound {
		t.Fatalf("expected status 404, got %d", rec.Code)
	}
}

func TestExtractHash(t *testing.T) {
	cases := []struct {
		name string
		path string
		want string
	}{
		{
			name: "valid note path",
			path: "/notes/abcd",
			want: "abcd",
		},
		{
			name: "missing hash",
			path: "/notes/",
			want: "",
		},
		{
			name: "wrong prefix",
			path: "/other/abcd",
			want: "",
		},
	}

	for _, tc := range cases {
		t.Run(tc.name, func(t *testing.T) {
			if got := extractHash(tc.path); got != tc.want {
				t.Fatalf("expected %q, got %q", tc.want, got)
			}
		})
	}
}

func TestHandlerTags_Add(t *testing.T) {
	env := newTestEnv(t)

	form := url.Values{}
	form.Set("tag", " Go ")
	req := httptest.NewRequest(http.MethodPost, "/notes/b2/tags", strings.NewReader(form.Encode()))
	req.Header.Set("Content-Type", "application/x-www-form-urlencoded")
	rec := httptest.NewRecorder()

	env.handler.ServeHTTP(rec, req)

	if rec.Code != http.StatusSeeOther {
		t.Fatalf("expected status 303, got %d", rec.Code)
	}

	n, err := env.storage.Get("b2")
	if err != nil {
		t.Fatalf("get note: %v", err)
	}
	if len(n.Tags) != 1 || n.Tags[0] != "go" {
		t.Fatalf("expected normalized tag on note, got %+v", n.Tags)
	}
}

func TestHandlerTags_Remove(t *testing.T) {
	env := newTestEnv(t)

	if err := env.storage.AddTag("b2", "go"); err != nil {
		t.Fatalf("seed tag: %v", err)
	}

	req := httptest.NewRequest(http.MethodPost, "/notes/b2/tags/go", nil)
	rec := httptest.NewRecorder()

	env.handler.ServeHTTP(rec, req)

	if rec.Code != http.StatusSeeOther {
		t.Fatalf("expected status 303, got %d", rec.Code)
	}

	n, err := env.storage.Get("b2")
	if err != nil {
		t.Fatalf("get note: %v", err)
	}
	if len(n.Tags) != 0 {
		t.Fatalf("expected tag to be removed, got %+v", n.Tags)
	}
}