package beta

import (
	"errors"
	"testing"

	"github.com/bwmarrin/discordgo"
)

const (
	betaGuild  = "1170934850157547600"
	otherGuild = "999000000000000001"
	testerRol  = "555000000000000001"
	testerID   = "777000000000000001"
)

func member(roles ...string) *discordgo.Member {
	return &discordgo.Member{Roles: roles, User: &discordgo.User{ID: testerID}}
}

func interaction(guildID string, m *discordgo.Member) *discordgo.InteractionCreate {
	return &discordgo.InteractionCreate{Interaction: &discordgo.Interaction{GuildID: guildID, Member: m}}
}

// useLookup makes the beta server say who holds which roles, as Discord would.
func useLookup(t *testing.T, rolesByUser map[string][]string, err error) *int {
	t.Helper()
	calls := 0
	SetRolesLookup(func(guildID, userID string) ([]string, error) {
		calls++
		if guildID != betaGuild {
			t.Errorf("the lookup must ask the beta server, asked %q", guildID)
		}
		return rolesByUser[userID], err
	})
	t.Cleanup(func() { lookup.Store(nil) })
	return &calls
}

func TestAllowedInTheBetaServer(t *testing.T) {
	cases := []struct {
		name        string
		guild, role string // configuration
		inGuild     string
		member      *discordgo.Member
		want        bool
		on, hasRole bool
	}{
		{"tester in the beta server", betaGuild, testerRol, betaGuild, member("1", testerRol), true, true, true},
		{"member without the role", betaGuild, testerRol, betaGuild, member("1", "2"), false, true, false},
		{"member with no roles at all", betaGuild, testerRol, betaGuild, member(), false, true, false},
		{"a DM has no member", betaGuild, testerRol, "", nil, false, false, false},
		{"a nil member in the beta server", betaGuild, testerRol, betaGuild, nil, false, true, false},
		{"no role configured: nobody", betaGuild, "", betaGuild, member(testerRol, ""), false, true, false},
		{"no beta server configured: nobody", "", testerRol, betaGuild, member(testerRol), false, false, false},
		{"a role ID that isn't a number is dropped", betaGuild, "tester-role", betaGuild, member("tester-role"), false, true, false},
		{"a server ID that isn't a number is dropped", "my-server", testerRol, "my-server", member(testerRol), false, false, false},
		{"a role that only contains the ID isn't a match", betaGuild, testerRol, betaGuild, member(testerRol + "9"), false, true, false},
		{"stray spaces in the configuration are ignored", " " + betaGuild + " ", " " + testerRol + "\n", betaGuild, member(testerRol), true, true, true},
	}
	for _, tc := range cases {
		t.Run(tc.name, func(t *testing.T) {
			Configure(tc.guild, tc.role, nil)
			if got := Allowed(tc.inGuild, tc.member); got != tc.want {
				t.Errorf("Allowed = %v, want %v", got, tc.want)
			}
			if got := AllowedInteraction(interaction(tc.inGuild, tc.member)); got != tc.want {
				t.Errorf("AllowedInteraction = %v, want %v", got, tc.want)
			}
			st := StatusOf(tc.inGuild, tc.member)
			if st.ServerEnabled != tc.on || st.HasRole != tc.hasRole {
				t.Errorf("StatusOf = %+v, want server on %v, tester %v", st, tc.on, tc.hasRole)
			}
		})
	}
}

func TestOptedInServers(t *testing.T) {
	roles := map[string][]string{testerID: {"1", testerRol}}

	t.Run("a tester in an opted-in server is allowed", func(t *testing.T) {
		Configure(betaGuild, testerRol, []string{otherGuild})
		calls := useLookup(t, roles, nil)
		if !Allowed(otherGuild, member()) { // roles in this server don't matter
			t.Error("tester in an opted-in server should be allowed")
		}
		if *calls != 1 {
			t.Errorf("the beta server should be asked once, was asked %d times", *calls)
		}
	})

	t.Run("the role in the other server doesn't count", func(t *testing.T) {
		Configure(betaGuild, testerRol, []string{otherGuild})
		useLookup(t, map[string][]string{}, nil)
		if Allowed(otherGuild, member(testerRol)) {
			t.Error("holding a role with that ID in another server must not make anyone a tester")
		}
	})

	t.Run("a server that didn't opt in is refused, and nothing is looked up", func(t *testing.T) {
		Configure(betaGuild, testerRol, []string{otherGuild})
		calls := useLookup(t, roles, nil)
		if Allowed("123000000000000001", member()) {
			t.Error("a server that didn't opt in must be refused")
		}
		if *calls != 0 {
			t.Error("no lookup for a server where beta is off")
		}
	})

	t.Run("a failing lookup fails closed", func(t *testing.T) {
		Configure(betaGuild, testerRol, []string{otherGuild})
		useLookup(t, roles, errors.New("Unknown Member"))
		if Allowed(otherGuild, member()) {
			t.Error("an error from Discord must mean no")
		}
	})

	t.Run("no lookup set: testers only qualify in the beta server", func(t *testing.T) {
		Configure(betaGuild, testerRol, []string{otherGuild})
		lookup.Store(nil)
		if Allowed(otherGuild, member()) {
			t.Error("without a lookup there is no way to know")
		}
		if !Allowed(betaGuild, member(testerRol)) {
			t.Error("the beta server doesn't need the lookup")
		}
	})

	t.Run("a user without an ID can't be looked up", func(t *testing.T) {
		Configure(betaGuild, testerRol, []string{otherGuild})
		useLookup(t, roles, nil)
		if Allowed(otherGuild, &discordgo.Member{}) || Allowed(otherGuild, &discordgo.Member{User: &discordgo.User{}}) {
			t.Error("no user, no access")
		}
	})

	t.Run("no role configured: nobody, even when the server opted in", func(t *testing.T) {
		Configure(betaGuild, "", []string{otherGuild})
		useLookup(t, map[string][]string{testerID: {""}}, nil)
		if Allowed(otherGuild, member()) {
			t.Error("without a role there are no testers")
		}
	})

	t.Run("bad IDs in the list are dropped", func(t *testing.T) {
		Configure(betaGuild, testerRol, []string{otherGuild, "not-an-id", "", " 5 "})
		got := Servers()
		if len(got) != 2 || got[0] != "5" || got[1] != otherGuild {
			t.Errorf("Servers = %v", got)
		}
	})

	t.Run("the beta server isn't listed twice", func(t *testing.T) {
		Configure(betaGuild, testerRol, []string{betaGuild, otherGuild})
		if got := Servers(); len(got) != 1 || got[0] != otherGuild {
			t.Errorf("Servers = %v", got)
		}
	})
}

func TestServerEnabledNeedsNoPerson(t *testing.T) {
	Configure(betaGuild, testerRol, []string{otherGuild})
	for guild, want := range map[string]bool{betaGuild: true, otherGuild: true, "123": false, "": false} {
		if got := ServerEnabled(guild); got != want {
			t.Errorf("ServerEnabled(%q) = %v, want %v", guild, got, want)
		}
	}
	current.Store(nil)
	if ServerEnabled(betaGuild) {
		t.Error("before Configure nothing is on")
	}
}

func TestNotConfiguredAtAll(t *testing.T) {
	current.Store(nil)
	if Allowed(betaGuild, member(testerRol)) || GuildID() != "" || len(Servers()) != 0 {
		t.Error("before Configure nothing is allowed and there's no beta server")
	}
	if AllowedInteraction(nil) || AllowedInteraction(&discordgo.InteractionCreate{}) {
		t.Error("a missing interaction is never allowed")
	}
}

func TestGateRunsTheHandlerOnlyForTesters(t *testing.T) {
	Configure(betaGuild, testerRol, []string{otherGuild})
	useLookup(t, map[string][]string{}, nil) // nobody holds the role in the beta server
	var answered []string
	orig := respond
	respond = func(_ *discordgo.Session, _ *discordgo.InteractionCreate, msg string) {
		answered = append(answered, msg)
	}
	t.Cleanup(func() { respond = orig })

	ran := 0
	h := Gate(func(*discordgo.Session, *discordgo.InteractionCreate) { ran++ })

	h(nil, interaction(betaGuild, member(testerRol)))
	if ran != 1 || len(answered) != 0 {
		t.Fatalf("a tester runs the handler without being refused: ran=%d answered=%v", ran, answered)
	}

	for name, i := range map[string]*discordgo.InteractionCreate{
		"no role":                interaction(betaGuild, member("1")),
		"opted-in, not a tester": interaction(otherGuild, member(testerRol)),
		"server not opted in":    interaction("123000000000000001", member(testerRol)),
		"DM":                     interaction("", nil),
	} {
		before := ran
		h(nil, i)
		if ran != before {
			t.Errorf("%s: the handler must not run", name)
		}
	}
	if len(answered) != 4 || answered[0] != denied {
		t.Errorf("each refusal is answered with the beta message: %v", answered)
	}

	useLookup(t, map[string][]string{testerID: {testerRol}}, nil)
	before := ran
	h(nil, interaction(otherGuild, member()))
	if ran != before+1 {
		t.Error("a tester in an opted-in server runs the handler")
	}
}

func TestGuardOnItsOwn(t *testing.T) {
	Configure(betaGuild, testerRol, nil)
	n := 0
	orig := respond
	respond = func(*discordgo.Session, *discordgo.InteractionCreate, string) { n++ }
	t.Cleanup(func() { respond = orig })

	if !Guard(nil, interaction(betaGuild, member(testerRol))) || n != 0 {
		t.Error("a tester passes without a reply")
	}
	if Guard(nil, interaction(betaGuild, member())) || n != 1 {
		t.Error("someone else is refused with a reply")
	}
}