package main

import (
	"bytes"
	"database/sql"
	"encoding/json"
	"fmt"
	"net/http"
	"net/http/httptest"
	"path/filepath"
	"strings"
	"testing"
	"time"
)

const testToken = "s3cret-token"

func testConfig() Config {
	return Config{
		Token:          testToken,
		AllowedOrigins: []string{"https://asuracomic.net", "https://demonicscans.org"},
		Port:           "8080",
	}
}

func newTestServer(t *testing.T) http.Handler {
	t.Helper()
	dbPath := filepath.Join(t.TempDir(), "test.db")
	store, err := OpenStore(dbPath)
	if err != nil {
		t.Fatalf("OpenStore: %v", err)
	}
	t.Cleanup(func() { store.Close() })
	return newRouter(store, testConfig())
}

func newTestStore(t *testing.T) *Store {
	t.Helper()
	store, err := OpenStore(filepath.Join(t.TempDir(), "test.db"))
	if err != nil {
		t.Fatalf("OpenStore: %v", err)
	}
	t.Cleanup(func() { store.Close() })
	return store
}

func auth(req *http.Request) *http.Request {
	req.Header.Set("Authorization", "Bearer "+testToken)
	return req
}

func TestHealthzNoAuth(t *testing.T) {
	srv := newTestServer(t)
	rr := httptest.NewRecorder()
	srv.ServeHTTP(rr, httptest.NewRequest(http.MethodGet, "/healthz", nil))
	if rr.Code != http.StatusOK {
		t.Fatalf("healthz status = %d, want 200", rr.Code)
	}
	if rr.Body.String() != "ok" {
		t.Fatalf("healthz body = %q, want ok", rr.Body.String())
	}
}

func TestAuthRequired(t *testing.T) {
	srv := newTestServer(t)
	cases := []struct {
		name   string
		header string
	}{
		{"no header", ""},
		{"bad token", "Bearer wrong"},
		{"not bearer", "Basic " + testToken},
		{"empty bearer", "Bearer "},
	}
	for _, tc := range cases {
		t.Run(tc.name, func(t *testing.T) {
			req := httptest.NewRequest(http.MethodGet, "/bookmarks", nil)
			if tc.header != "" {
				req.Header.Set("Authorization", tc.header)
			}
			rr := httptest.NewRecorder()
			srv.ServeHTTP(rr, req)
			if rr.Code != http.StatusUnauthorized {
				t.Fatalf("status = %d, want 401", rr.Code)
			}
		})
	}
}

func TestAuthAccepted(t *testing.T) {
	srv := newTestServer(t)
	rr := httptest.NewRecorder()
	srv.ServeHTTP(rr, auth(httptest.NewRequest(http.MethodGet, "/bookmarks", nil)))
	if rr.Code != http.StatusOK {
		t.Fatalf("status = %d, want 200", rr.Code)
	}
	if got := rr.Body.String(); got != "[]\n" {
		t.Fatalf("empty list body = %q, want []", got)
	}
}

func TestCORSPreflight(t *testing.T) {
	srv := newTestServer(t)
	req := httptest.NewRequest(http.MethodOptions, "/bookmarks/asura:foo-1", nil)
	req.Header.Set("Origin", "https://asuracomic.net")
	req.Header.Set("Access-Control-Request-Method", "PUT")
	rr := httptest.NewRecorder()
	srv.ServeHTTP(rr, req)

	if rr.Code != http.StatusNoContent {
		t.Fatalf("preflight status = %d, want 204", rr.Code)
	}
	if got := rr.Header().Get("Access-Control-Allow-Origin"); got != "https://asuracomic.net" {
		t.Fatalf("Allow-Origin = %q, want reflected origin", got)
	}
	if got := rr.Header().Get("Access-Control-Allow-Methods"); got == "" {
		t.Fatal("Allow-Methods missing")
	}
	if got := rr.Header().Get("Access-Control-Allow-Headers"); got == "" {
		t.Fatal("Allow-Headers missing")
	}
}

func TestCORSDisallowedOrigin(t *testing.T) {
	srv := newTestServer(t)
	req := httptest.NewRequest(http.MethodOptions, "/bookmarks", nil)
	req.Header.Set("Origin", "https://evil.example")
	rr := httptest.NewRecorder()
	srv.ServeHTTP(rr, req)
	if got := rr.Header().Get("Access-Control-Allow-Origin"); got != "" {
		t.Fatalf("Allow-Origin = %q, want empty for disallowed origin", got)
	}
}

func TestBookmarkRoundTrip(t *testing.T) {
	srv := newTestServer(t)
	key := "asura:solo-leveling-123"
	in := Bookmark{
		Title:          "Solo Leveling",
		SeriesURL:      "https://asuracomic.net/series/solo-leveling-123",
		Cover:          "https://asuracomic.net/cover.jpg",
		LastChapter:    "Chapter 10",
		LastChapterNum: 10,
		LastChapterURL: "https://asuracomic.net/series/solo-leveling-123/chapter/10",
	}
	body, _ := json.Marshal(in)

	// PUT
	rr := httptest.NewRecorder()
	srv.ServeHTTP(rr, auth(httptest.NewRequest(http.MethodPut, "/bookmarks/"+key, bytes.NewReader(body))))
	if rr.Code != http.StatusOK {
		t.Fatalf("PUT status = %d, want 200", rr.Code)
	}
	var stored Bookmark
	if err := json.Unmarshal(rr.Body.Bytes(), &stored); err != nil {
		t.Fatalf("decode PUT response: %v", err)
	}
	if stored.Key != key || stored.Site != "asura" || stored.SeriesID != "solo-leveling-123" {
		t.Fatalf("derived fields wrong: %+v", stored)
	}
	if stored.UpdatedAt == 0 {
		t.Fatal("server did not set updated_at")
	}

	// GET
	rr = httptest.NewRecorder()
	srv.ServeHTTP(rr, auth(httptest.NewRequest(http.MethodGet, "/bookmarks", nil)))
	var list []Bookmark
	if err := json.Unmarshal(rr.Body.Bytes(), &list); err != nil {
		t.Fatalf("decode list: %v", err)
	}
	if len(list) != 1 || list[0].Key != key || list[0].LastChapterNum != 10 {
		t.Fatalf("GET list wrong: %+v", list)
	}

	// PUT again (upsert, progress advance)
	in.LastChapter, in.LastChapterNum = "Chapter 11", 11
	body, _ = json.Marshal(in)
	rr = httptest.NewRecorder()
	srv.ServeHTTP(rr, auth(httptest.NewRequest(http.MethodPut, "/bookmarks/"+key, bytes.NewReader(body))))
	if rr.Code != http.StatusOK {
		t.Fatalf("second PUT status = %d", rr.Code)
	}
	rr = httptest.NewRecorder()
	srv.ServeHTTP(rr, auth(httptest.NewRequest(http.MethodGet, "/bookmarks", nil)))
	json.Unmarshal(rr.Body.Bytes(), &list)
	if len(list) != 1 || list[0].LastChapterNum != 11 {
		t.Fatalf("upsert did not update in place: %+v", list)
	}

	// DELETE
	rr = httptest.NewRecorder()
	srv.ServeHTTP(rr, auth(httptest.NewRequest(http.MethodDelete, "/bookmarks/"+key, nil)))
	if rr.Code != http.StatusNoContent {
		t.Fatalf("DELETE status = %d, want 204", rr.Code)
	}
	rr = httptest.NewRecorder()
	srv.ServeHTTP(rr, auth(httptest.NewRequest(http.MethodGet, "/bookmarks", nil)))
	json.Unmarshal(rr.Body.Bytes(), &list)
	if len(list) != 0 {
		t.Fatalf("after delete list = %+v, want empty", list)
	}
}

// putBookmark PUTs b at key and returns the bookmark the server echoes back,
// which is the row as actually stored (not the request payload).
func putBookmark(t *testing.T, srv http.Handler, key string, b Bookmark) Bookmark {
	t.Helper()
	body, _ := json.Marshal(b)
	rr := httptest.NewRecorder()
	srv.ServeHTTP(rr, auth(httptest.NewRequest(http.MethodPut, "/bookmarks/"+key, bytes.NewReader(body))))
	if rr.Code != http.StatusOK {
		t.Fatalf("PUT %s status = %d, body = %s", key, rr.Code, rr.Body.String())
	}
	var out Bookmark
	if err := json.Unmarshal(rr.Body.Bytes(), &out); err != nil {
		t.Fatalf("decode PUT response: %v", err)
	}
	return out
}

func getBookmarks(t *testing.T, srv http.Handler) []Bookmark {
	t.Helper()
	rr := httptest.NewRecorder()
	srv.ServeHTTP(rr, auth(httptest.NewRequest(http.MethodGet, "/bookmarks", nil)))
	if rr.Code != http.StatusOK {
		t.Fatalf("GET status = %d", rr.Code)
	}
	var list []Bookmark
	if err := json.Unmarshal(rr.Body.Bytes(), &list); err != nil {
		t.Fatalf("decode list: %v", err)
	}
	return list
}

func floatPtr(f float64) *float64 { return &f }

// updated_at drives list ordering, so it must move only on a real progress
// advance — never on a favorite toggle or a latest-chapter capture.
func TestUpsertConditionalUpdatedAt(t *testing.T) {
	cases := []struct {
		name       string
		mutate     func(Bookmark) Bookmark
		wantBumped bool
	}{
		{
			name:       "unchanged progress",
			mutate:     func(b Bookmark) Bookmark { return b },
			wantBumped: false,
		},
		{
			name: "changed progress",
			mutate: func(b Bookmark) Bookmark {
				b.LastChapter, b.LastChapterNum = "Chapter 11", 11
				return b
			},
			wantBumped: true,
		},
		{
			name: "favorite only",
			mutate: func(b Bookmark) Bookmark {
				b.Favorite = true
				return b
			},
			wantBumped: false,
		},
		{
			name: "latest chapter only",
			mutate: func(b Bookmark) Bookmark {
				b.LatestChapter, b.LatestChapterNum = "Chapter 15", floatPtr(15)
				return b
			},
			wantBumped: false,
		},
		{
			name: "unrelated metadata only",
			mutate: func(b Bookmark) Bookmark {
				b.Title, b.Cover = "Renamed", "https://example.test/new.jpg"
				return b
			},
			wantBumped: false,
		},
	}

	for i, tc := range cases {
		t.Run(tc.name, func(t *testing.T) {
			srv := newTestServer(t)
			key := fmt.Sprintf("asura:cond-%d", i)

			first := putBookmark(t, srv, key, Bookmark{
				Title:          "Test",
				LastChapter:    "Chapter 10",
				LastChapterNum: 10,
			})
			if first.UpdatedAt == 0 {
				t.Fatal("new bookmark did not get updated_at set")
			}

			// Guarantee a later wall-clock ms so a real bump is observable.
			time.Sleep(2 * time.Millisecond)

			second := putBookmark(t, srv, key, tc.mutate(first))
			if tc.wantBumped && second.UpdatedAt <= first.UpdatedAt {
				t.Fatalf("updated_at = %d, want > %d", second.UpdatedAt, first.UpdatedAt)
			}
			if !tc.wantBumped && second.UpdatedAt != first.UpdatedAt {
				t.Fatalf("updated_at = %d, want preserved %d", second.UpdatedAt, first.UpdatedAt)
			}

			// The PUT response must match what a subsequent GET reports.
			list := getBookmarks(t, srv)
			if len(list) != 1 {
				t.Fatalf("list = %+v, want 1 item", list)
			}
			if list[0].UpdatedAt != second.UpdatedAt {
				t.Fatalf("GET updated_at = %d, PUT echoed %d", list[0].UpdatedAt, second.UpdatedAt)
			}
		})
	}
}

func TestFavoriteRoundTrip(t *testing.T) {
	srv := newTestServer(t)
	key := "demonic:some-series"

	stored := putBookmark(t, srv, key, Bookmark{Title: "Fav", Favorite: true})
	if !stored.Favorite {
		t.Fatalf("PUT response favorite = false, want true")
	}

	list := getBookmarks(t, srv)
	if len(list) != 1 || !list[0].Favorite {
		t.Fatalf("favorite did not round-trip: %+v", list)
	}

	// Unfavoriting must persist too (guards against a write that only ever ORs in true).
	stored = putBookmark(t, srv, key, Bookmark{Title: "Fav", Favorite: false})
	if stored.Favorite {
		t.Fatal("PUT response favorite = true after unfavorite")
	}
	list = getBookmarks(t, srv)
	if len(list) != 1 || list[0].Favorite {
		t.Fatalf("unfavorite did not round-trip: %+v", list)
	}
}

func TestLatestChapterNullable(t *testing.T) {
	srv := newTestServer(t)
	key := "asura:latest-test"

	// Never captured: latest_chapter_num must serialize as JSON null.
	body, _ := json.Marshal(Bookmark{Title: "No latest yet"})
	rr := httptest.NewRecorder()
	srv.ServeHTTP(rr, auth(httptest.NewRequest(http.MethodPut, "/bookmarks/"+key, bytes.NewReader(body))))
	if rr.Code != http.StatusOK {
		t.Fatalf("PUT status = %d", rr.Code)
	}
	if !strings.Contains(rr.Body.String(), `"latest_chapter_num":null`) {
		t.Fatalf("want latest_chapter_num null in response, got %s", rr.Body.String())
	}

	list := getBookmarks(t, srv)
	if len(list) != 1 || list[0].LatestChapterNum != nil {
		t.Fatalf("latest_chapter_num = %v, want nil", list[0].LatestChapterNum)
	}

	// Once captured it round-trips as a value.
	stored := putBookmark(t, srv, key, Bookmark{
		Title:            "No latest yet",
		LatestChapter:    "Chapter 162",
		LatestChapterNum: floatPtr(162),
	})
	if stored.LatestChapterNum == nil || *stored.LatestChapterNum != 162 {
		t.Fatalf("PUT response latest_chapter_num = %v, want 162", stored.LatestChapterNum)
	}
	list = getBookmarks(t, srv)
	if len(list) != 1 || list[0].LatestChapterNum == nil || *list[0].LatestChapterNum != 162 {
		t.Fatalf("latest chapter did not round-trip: %+v", list)
	}
	if list[0].LatestChapter != "Chapter 162" {
		t.Fatalf("latest_chapter = %q, want %q", list[0].LatestChapter, "Chapter 162")
	}
}

// The deployed database predates favorite/latest_chapter*, and CREATE TABLE
// IF NOT EXISTS will not add them — OpenStore must migrate in place.
func TestOpenStoreMigratesLegacySchema(t *testing.T) {
	dbPath := filepath.Join(t.TempDir(), "legacy.db")

	legacy, err := sql.Open("sqlite", dbPath)
	if err != nil {
		t.Fatalf("open legacy db: %v", err)
	}
	if _, err := legacy.Exec(`
		CREATE TABLE bookmarks (
		  key              TEXT PRIMARY KEY,
		  site             TEXT NOT NULL,
		  series_id        TEXT NOT NULL,
		  title            TEXT,
		  series_url       TEXT,
		  cover            TEXT,
		  last_chapter     TEXT,
		  last_chapter_num REAL,
		  last_chapter_url TEXT,
		  updated_at       INTEGER NOT NULL
		)`); err != nil {
		t.Fatalf("create legacy schema: %v", err)
	}
	if _, err := legacy.Exec(`
		INSERT INTO bookmarks (key, site, series_id, title, last_chapter, last_chapter_num, updated_at)
		VALUES ('asura:legacy', 'asura', 'legacy', 'Legacy Series', 'Chapter 7', 7, 123)`); err != nil {
		t.Fatalf("seed legacy row: %v", err)
	}
	if err := legacy.Close(); err != nil {
		t.Fatalf("close legacy db: %v", err)
	}

	store, err := OpenStore(dbPath)
	if err != nil {
		t.Fatalf("OpenStore on legacy db: %v", err)
	}
	t.Cleanup(func() { store.Close() })

	list, err := store.List()
	if err != nil {
		t.Fatalf("List: %v", err)
	}
	if len(list) != 1 || list[0].Key != "asura:legacy" {
		t.Fatalf("legacy row lost: %+v", list)
	}
	got := list[0]
	if got.Title != "Legacy Series" || got.LastChapterNum != 7 || got.UpdatedAt != 123 {
		t.Fatalf("legacy data mangled: %+v", got)
	}
	if got.Favorite || got.LatestChapter != "" || got.LatestChapterNum != nil {
		t.Fatalf("new columns should default empty, got %+v", got)
	}

	// Reopening an already-migrated database must be a no-op, not an error.
	store2, err := OpenStore(dbPath)
	if err != nil {
		t.Fatalf("OpenStore is not idempotent: %v", err)
	}
	store2.Close()
}

func TestStoreGet(t *testing.T) {
	store := newTestStore(t)
	if _, err := store.Upsert(Bookmark{
		Key: "asura:solo", Site: "asura", SeriesID: "solo",
		Title: "Solo Leveling", LastChapterNum: 45, UpdatedAt: 1000,
	}); err != nil {
		t.Fatalf("Upsert: %v", err)
	}

	got, ok, err := store.Get("asura:solo")
	if err != nil {
		t.Fatalf("Get: %v", err)
	}
	if !ok {
		t.Fatal("Get ok = false, want true")
	}
	if got.Title != "Solo Leveling" || got.LastChapterNum != 45 {
		t.Fatalf("Get = %+v, want title/chapter preserved", got)
	}
}

func TestStoreGetMissing(t *testing.T) {
	store := newTestStore(t)
	_, ok, err := store.Get("asura:nope")
	if err != nil {
		t.Fatalf("Get missing returned error %v, want nil", err)
	}
	if ok {
		t.Fatal("Get ok = true for missing key, want false")
	}
}

func TestBookmarkHasNewChapter(t *testing.T) {
	num := func(f float64) *float64 { return &f }
	cases := []struct {
		name string
		b    Bookmark
		want bool
	}{
		{"latest ahead", Bookmark{LastChapterNum: 45, LatestChapterNum: num(47)}, true},
		{"latest equal", Bookmark{LastChapterNum: 45, LatestChapterNum: num(45)}, false},
		{"latest behind", Bookmark{LastChapterNum: 45, LatestChapterNum: num(44)}, false},
		{"latest unknown", Bookmark{LastChapterNum: 45}, false},
	}
	for _, tc := range cases {
		t.Run(tc.name, func(t *testing.T) {
			if got := tc.b.HasNewChapter(); got != tc.want {
				t.Fatalf("HasNewChapter() = %v, want %v", got, tc.want)
			}
		})
	}
}

func TestBookmarkContinueURL(t *testing.T) {
	cases := []struct {
		name string
		b    Bookmark
		want string
	}{
		{"chapter url present", Bookmark{LastChapterURL: "/ch/45", SeriesURL: "/series"}, "/ch/45"},
		{"falls back to series", Bookmark{SeriesURL: "/series"}, "/series"},
		{"both empty", Bookmark{}, ""},
	}
	for _, tc := range cases {
		t.Run(tc.name, func(t *testing.T) {
			if got := tc.b.ContinueURL(); got != tc.want {
				t.Fatalf("ContinueURL() = %q, want %q", got, tc.want)
			}
		})
	}
}

func TestLoadConfigWebPassword(t *testing.T) {
	t.Setenv("API_TOKEN", "token-abc")
	t.Setenv("WEB_PASSWORD", "hunter2")
	if got := loadConfig().WebPassword; got != "hunter2" {
		t.Fatalf("WebPassword = %q, want hunter2", got)
	}

	t.Setenv("WEB_PASSWORD", "")
	if got := loadConfig().WebPassword; got != "" {
		t.Fatalf("WebPassword = %q with the variable unset, want empty", got)
	}
}