package surf

import (
	"io/fs"
	"net/http"
	"os"
	"path/filepath"
	"strings"
	"testing"
	"testing/fstest"

	"git.golem15.com/golem15/summercms/modules/backpack"
	"git.golem15.com/golem15/summercms/modules/compass"
	"git.golem15.com/golem15/summercms/modules/pact"
	"git.golem15.com/golem15/summercms/modules/party"
)

// TestPhase10AdminPrefixCollision fails boot when a plugin other than cabana
// registers a route at or under the admin prefix (backend.uri), which would
// otherwise shadow or be shadowed by the admin SPA and API.
func TestPhase10AdminPrefixCollision(t *testing.T) {
	for _, tc := range []struct {
		name   string
		method string
		path   string
		raw    bool
	}{
		{"exact prefix", http.MethodGet, "/acme-admin", false},
		{"under prefix", http.MethodPost, "/acme-admin/hook", false},
		{"raw under api", http.MethodGet, "/acme-admin/api/v1/extra", true},
		{"deeper path", http.MethodGet, "/acme-admin/a/b/c", false},
		{"exact prefix raw", http.MethodPost, "/acme-admin", true},
	} {
		t.Run(tc.name, func(t *testing.T) {
			app := adminPrefixApp(t)
			plugins := []party.Plugin{
				adminPrefixPlugin{},
				prefixRoutePlugin{id: "acme.intruder", method: tc.method, path: tc.path, raw: tc.raw},
			}
			_, err := BuildRouter(app, plugins)
			if err == nil {
				t.Fatalf("BuildRouter accepted %s %s under the admin prefix", tc.method, tc.path)
			}
			for _, want := range []string{tc.method, tc.path, "acme.intruder", "/acme-admin"} {
				if !strings.Contains(err.Error(), want) {
					t.Fatalf("error %q does not name %q", err, want)
				}
			}
		})
	}

	t.Run("sibling path is allowed", func(t *testing.T) {
		app := adminPrefixApp(t)
		plugins := []party.Plugin{
			adminPrefixPlugin{},
			prefixRoutePlugin{id: "acme.neighbour", method: http.MethodGet, path: "/acme-adminx"},
		}
		if _, err := BuildRouter(app, plugins); err != nil {
			t.Fatalf("sibling path rejected: %v", err)
		}
	})

	t.Run("default /backend prefix", func(t *testing.T) {
		for _, tc := range []struct {
			path    string
			collide bool
		}{
			{"/backend", true},
			{"/backend/deep/hook", true},
			{"/backendx", false},
			{"/back", false},
			{"/api/backend", false},
		} {
			app := adminPrefixAppWith(t, "")
			plugins := []party.Plugin{
				adminPrefixPlugin{},
				prefixRoutePlugin{id: "acme.intruder", method: http.MethodGet, path: tc.path},
			}
			_, err := BuildRouter(app, plugins)
			if tc.collide && (err == nil || !strings.Contains(err.Error(), "/backend")) {
				t.Fatalf("%s under the default prefix: err=%v", tc.path, err)
			}
			if !tc.collide && err != nil {
				t.Fatalf("%s rejected next to the default prefix: %v", tc.path, err)
			}
		}
	})

	t.Run("no admin means no prefix check", func(t *testing.T) {
		app := adminPrefixApp(t)
		plugins := []party.Plugin{prefixRoutePlugin{id: "acme.site", method: http.MethodGet, path: "/acme-admin"}}
		if _, err := BuildRouter(app, plugins); err != nil {
			t.Fatalf("a route at the prefix without admin controllers was rejected: %v", err)
		}
		if err := (&Router{}).checkAdminPrefix(""); err != nil {
			t.Fatalf("empty prefix: %v", err)
		}
	})
}

func adminPrefixApp(t *testing.T) *backpack.App {
	t.Helper()
	return adminPrefixAppWith(t, "/acme-admin")
}

// adminPrefixAppWith configures backend.uri; an empty uri keeps the default.
func adminPrefixAppWith(t *testing.T, uri string) *backpack.App {
	t.Helper()
	dir := t.TempDir()
	if err := os.WriteFile(filepath.Join(dir, "app.yaml"), []byte("name: admin-prefix\n"), 0o644); err != nil {
		t.Fatal(err)
	}
	if err := os.WriteFile(filepath.Join(dir, "http.yaml"), []byte("body_limits:\n  default_bytes: 1024\n  upload_bytes: 1024\n"), 0o644); err != nil {
		t.Fatal(err)
	}
	if uri != "" {
		if err := os.WriteFile(filepath.Join(dir, "backend.yaml"), []byte("uri: "+uri+"\n"), 0o644); err != nil {
			t.Fatal(err)
		}
	}
	cfg, err := compass.Open(compass.Options{
		Dir:     dir,
		Environ: []string{"SUMMER_ENV=development", "SUMMER_ADMIN__JWT__SECRET=summercms-test-only-admin-hs256-secret"},
	})
	if err != nil {
		t.Fatal(err)
	}
	return backpack.New(cfg)
}

type adminPrefixPlugin struct{}

func (adminPrefixPlugin) ID() string                   { return "acme.demo" }
func (adminPrefixPlugin) Requires() []string           { return nil }
func (adminPrefixPlugin) Register(*backpack.App) error { return nil }
func (adminPrefixPlugin) Boot(*backpack.App) error     { return nil }
func (adminPrefixPlugin) AdminControllers() []pact.AdminController {
	return []pact.AdminController{adminPrefixController{}}
}
func (adminPrefixPlugin) AdminFS() fs.FS {
	return fstest.MapFS{
		"controllers/widgets/config_list.yaml": &fstest.MapFile{Data: []byte("list: ~/plugins/acme/demo/models/widget/columns.yaml\nmodelClass: Widget\nrecordsPerPage: 20\n")},
		"models/widget/columns.yaml":           &fstest.MapFile{Data: []byte("columns:\n    name:\n        label: Name\n")},
	}
}

type adminPrefixController struct{}

func (adminPrefixController) ID() string        { return "acme.demo.widgets" }
func (adminPrefixController) ModelName() string { return "Widget" }
func (adminPrefixController) ConfigDir() string { return "controllers/widgets" }

type prefixRoutePlugin struct {
	id     string
	method string
	path   string
	raw    bool
}

func (p prefixRoutePlugin) ID() string                   { return p.id }
func (p prefixRoutePlugin) Requires() []string           { return nil }
func (p prefixRoutePlugin) Register(*backpack.App) error { return nil }
func (p prefixRoutePlugin) Boot(*backpack.App) error     { return nil }
func (p prefixRoutePlugin) Routes(r pact.Router) error {
	h := func(w http.ResponseWriter, _ *http.Request) { w.WriteHeader(http.StatusNoContent) }
	open := r.Group
	if p.raw {
		open = r.GroupRaw
	}
	open("", nil, func(g pact.Router) {
		switch p.method {
		case http.MethodPost:
			g.Post(p.path, h)
		default:
			g.Get(p.path, h)
		}
	})
	return nil
}