package web

import (
	"bytes"
	"context"
	"encoding/json"
	"net/http"
	"net/http/httptest"
	"path/filepath"
	"strings"
	"testing"

	"git.veillax.com/Veillax/megalodon/internal/config"
	"git.veillax.com/Veillax/megalodon/internal/manager"
)

type env struct {
	t      *testing.T
	ts     *httptest.Server
	cfg    *config.Holder
	tokens map[config.Role]string
}

func setup(t *testing.T) *env {
	t.Helper()
	h, err := config.Load(filepath.Join(t.TempDir(), "megalodon.json"))
	if err != nil {
		t.Fatal(err)
	}
	e := &env{t: t, cfg: h, tokens: map[config.Role]string{}}
	hash, _ := config.HashPassword("hunter2hunter2")
	err = h.Update(func(c *config.Config) error {
		c.DataDir = t.TempDir()
		c.Users = []config.User{{Name: "root", Role: config.Admin, Hash: hash}, {Name: "mod", Role: config.Moderator, Hash: hash}}
		for _, r := range []config.Role{config.Viewer, config.Moderator, config.Admin} {
			tok, th, _ := config.NewToken()
			e.tokens[r] = tok
			c.Tokens = append(c.Tokens, config.Token{Name: string(r), Role: r, Hash: th})
		}
		return nil
	})
	if err != nil {
		t.Fatal(err)
	}
	m, err := manager.New(h)
	if err != nil {
		t.Fatal(err)
	}
	ctx, cancel := context.WithCancel(context.Background())
	m.Start(ctx)
	e.ts = httptest.NewServer(New(h, m, "test").Handler())
	t.Cleanup(func() { e.ts.Close(); cancel(); m.Wait() })
	return e
}

func (e *env) do(method, path, token string, body any, hdr ...string) *http.Response {
	e.t.Helper()
	var rd *bytes.Reader
	if body != nil {
		b, _ := json.Marshal(body)
		rd = bytes.NewReader(b)
	} else {
		rd = bytes.NewReader(nil)
	}
	req, _ := http.NewRequest(method, e.ts.URL+path, rd)
	if token != "" {
		req.Header.Set("Authorization", "Bearer "+token)
	}
	for i := 0; i+1 < len(hdr); i += 2 {
		req.Header.Set(hdr[i], hdr[i+1])
	}
	resp, err := http.DefaultClient.Do(req)
	if err != nil {
		e.t.Fatal(err)
	}
	return resp
}

func status(t *testing.T, resp *http.Response, want int) {
	t.Helper()
	defer resp.Body.Close()
	if resp.StatusCode != want {
		t.Fatalf("%s %s: got %d, want %d", resp.Request.Method, resp.Request.URL.Path, resp.StatusCode, want)
	}
}

func TestRolesAreEnforced(t *testing.T) {
	e := setup(t)
	status(t, e.do("GET", "/api/servers", "", nil), 401)
	status(t, e.do("GET", "/api/servers", "mgl_bogus", nil), 401)
	status(t, e.do("GET", "/api/servers", e.tokens[config.Viewer], nil), 200)

	status(t, e.do("GET", "/api/bans", e.tokens[config.Viewer], nil), 403)
	status(t, e.do("GET", "/api/bans", e.tokens[config.Moderator], nil), 200)

	status(t, e.do("GET", "/api/settings", e.tokens[config.Moderator], nil), 403)
	status(t, e.do("GET", "/api/settings", e.tokens[config.Admin], nil), 200)

	// The raw console is admin only; a moderator may kick but the check comes before any server is looked up.
	status(t, e.do("POST", "/api/actions", e.tokens[config.Moderator], map[string]any{"action": "exec", "command": "DoExit"}), 403)
	status(t, e.do("POST", "/api/actions", e.tokens[config.Viewer], map[string]any{"action": "broadcast", "message": "hi"}), 403)
	status(t, e.do("POST", "/api/actions", e.tokens[config.Moderator], map[string]any{"action": "broadcast", "message": "hi"}), 400) // no servers configured
}

func TestLoginSessionAndCSRF(t *testing.T) {
	e := setup(t)
	login := func(pw string) *http.Response {
		return e.do("POST", "/api/login", "", map[string]string{"username": "root", "password": pw}, "X-Megalodon", "1")
	}
	status(t, login("wrong"), 401)
	status(t, e.do("POST", "/api/login", "", map[string]string{"username": "root", "password": "hunter2hunter2"}), 403) // no CSRF header

	resp := login("hunter2hunter2")
	var cookie *http.Cookie
	for _, c := range resp.Cookies() {
		if c.Name == cookieName {
			cookie = c
		}
	}
	status(t, resp, 200)
	if cookie == nil || !cookie.HttpOnly || cookie.SameSite != http.SameSiteStrictMode {
		t.Fatalf("session cookie is not locked down: %+v", cookie)
	}
	withCookie := func(method, path string, hdr ...string) *http.Response {
		req, _ := http.NewRequest(method, e.ts.URL+path, strings.NewReader("{}"))
		req.AddCookie(cookie)
		for i := 0; i+1 < len(hdr); i += 2 {
			req.Header.Set(hdr[i], hdr[i+1])
		}
		r, err := http.DefaultClient.Do(req)
		if err != nil {
			t.Fatal(err)
		}
		return r
	}
	status(t, withCookie("GET", "/api/me"), 200)
	status(t, withCookie("POST", "/api/actions"), 403)                     // cookie without the header: a cross-site form post
	status(t, withCookie("POST", "/api/actions", "X-Megalodon", "1"), 400) // allowed through, fails only for lack of servers
	status(t, withCookie("POST", "/api/logout", "X-Megalodon", "1"), 200)
	status(t, withCookie("GET", "/api/me"), 401)
}

func TestLoginIsRateLimited(t *testing.T) {
	e := setup(t)
	var last int
	for i := 0; i < maxLoginFails+2; i++ {
		resp := e.do("POST", "/api/login", "", map[string]string{"username": "root", "password": "nope"}, "X-Megalodon", "1")
		last = resp.StatusCode
		resp.Body.Close()
	}
	if last != http.StatusTooManyRequests {
		t.Fatalf("got %d after repeated failures", last)
	}
	// Even the right password is refused during the lockout.
	status(t, e.do("POST", "/api/login", "", map[string]string{"username": "root", "password": "hunter2hunter2"}, "X-Megalodon", "1"), 429)
}

func TestSettingsAreValidated(t *testing.T) {
	e := setup(t)
	admin := e.tokens[config.Admin]
	bad := map[string]any{"jobs": []map[string]any{{"name": "x", "enabled": true, "action": "save", "every": "5s"}}}
	status(t, e.do("PUT", "/api/settings", admin, bad), 400)

	good := map[string]any{
		"jobs":        []map[string]any{{"name": "Hourly save", "enabled": true, "action": "save", "every": "1h"}},
		"macros":      []map[string]any{{"name": "Day", "commands": []string{"SetTimeOfDay 12:00"}, "role": "moderator"}},
		"chat_filter": map[string]any{"action": "warn"},
	}
	status(t, e.do("PUT", "/api/settings", admin, good), 200)
	resp := e.do("GET", "/api/settings", admin, nil)
	var got settings
	json.NewDecoder(resp.Body).Decode(&got)
	resp.Body.Close()
	if len(got.Jobs) != 1 || got.Jobs[0].ID == "" {
		t.Fatalf("job was not saved with an id: %+v", got.Jobs)
	}
	// Moderators see the macros they may run, admins' secrets stay out of /api/me.
	resp = e.do("GET", "/api/me", e.tokens[config.Moderator], nil)
	var me struct{ Macros []struct{ Name string } }
	json.NewDecoder(resp.Body).Decode(&me)
	resp.Body.Close()
	if len(me.Macros) != 1 || me.Macros[0].Name != "Day" {
		t.Fatalf("got %+v", me.Macros)
	}
}

func TestUsersCannotLockEveryoneOut(t *testing.T) {
	e := setup(t)
	admin := e.tokens[config.Admin]
	status(t, e.do("DELETE", "/api/users/root", admin, nil), 400) // the only admin
	status(t, e.do("POST", "/api/users", admin, map[string]string{"name": "root", "role": "viewer"}), 400)
	status(t, e.do("POST", "/api/users", admin, map[string]string{"name": "new", "role": "viewer", "password": "short"}), 400)
	status(t, e.do("POST", "/api/users", admin, map[string]string{"name": "new", "role": "viewer", "password": "long enough pw"}), 200)
	status(t, e.do("DELETE", "/api/users/new", admin, nil), 200)
}

func TestViewersDoNotSeeAuditEvents(t *testing.T) {
	e := setup(t)
	status(t, e.do("POST", "/api/users", e.tokens[config.Admin], map[string]string{"name": "n", "role": "viewer", "password": "long enough pw"}), 200)
	count := func(token string) int {
		resp := e.do("GET", "/api/events?type=audit", token, nil)
		defer resp.Body.Close()
		var evs []manager.Event
		json.NewDecoder(resp.Body).Decode(&evs)
		return len(evs)
	}
	if count(e.tokens[config.Moderator]) == 0 {
		t.Fatal("moderators should see audit events")
	}
	if count(e.tokens[config.Viewer]) != 0 {
		t.Fatal("viewers must not see audit events")
	}
}

func TestSecurityHeadersAndStaticPage(t *testing.T) {
	e := setup(t)
	resp := e.do("GET", "/", "", nil)
	defer resp.Body.Close()
	if resp.StatusCode != 200 || !strings.Contains(resp.Header.Get("Content-Security-Policy"), "default-src 'none'") || resp.Header.Get("X-Frame-Options") != "DENY" {
		t.Fatalf("status %d, headers %v", resp.StatusCode, resp.Header)
	}
	status(t, e.do("GET", "/healthz", "", nil), 200)
}