package station_test

import (
	"os"
	"path/filepath"
	"strings"
	"testing"

	jsonv2 "encoding/json/v2"

	"gitea.neitzel.de/konrad/funknetz/station"
)

func TestMissingConfigIsCreatedAndRejected(t *testing.T) {
	path := filepath.Join(t.TempDir(), ".funknetz.json")

	_, err := station.New(station.Options{ConfigPath: path})
	if err == nil {
		t.Fatal("New() error = nil, want a rejection after creating the file")
	}
	if !strings.Contains(err.Error(), "created") {
		t.Fatalf("New() error = %q, want it to say the file was created", err.Error())
	}

	info, err := os.Stat(path)
	if err != nil {
		t.Fatal(err)
	}
	if got, want := info.Mode().Perm(), os.FileMode(0o600); got != want {
		t.Fatalf("mode = %o, want %o", got, want)
	}

	body, err := os.ReadFile(path)
	if err != nil {
		t.Fatal(err)
	}
	var got map[string]any
	if err := jsonv2.Unmarshal(body, &got); err != nil {
		t.Fatalf("created file is not JSON: %v\n%s", err, body)
	}
	if got["host"] != "" || got["callsign"] != "" || got["authKey"] != "" {
		t.Fatalf("string fields = %#v, want empty host, callsign, and authKey", got)
	}
	if got["port"] != float64(0) || got["talkGroup"] != float64(0) {
		t.Fatalf("numeric fields = %#v, want port and talkGroup at zero", got)
	}
}

func TestExistingConfigIsNotRewritten(t *testing.T) {
	path := filepath.Join(t.TempDir(), "funknetz.json")
	original := []byte("{\"host\":\"127.0.0.1\",\"port\":5308,\"callsign\":\"DL1ABC\",\"authKey\":\"a b\",\"talkGroup\":20}\n")
	if err := os.WriteFile(path, original, 0o640); err != nil {
		t.Fatal(err)
	}

	if _, err := station.New(station.Options{ConfigPath: path}); err != nil {
		t.Fatal(err)
	}
	got, err := os.ReadFile(path)
	if err != nil {
		t.Fatal(err)
	}
	if string(got) != string(original) {
		t.Fatalf("file = %q, want %q", got, original)
	}
	info, err := os.Stat(path)
	if err != nil {
		t.Fatal(err)
	}
	if got, want := info.Mode().Perm(), os.FileMode(0o640); got != want {
		t.Fatalf("mode = %o, want %o", got, want)
	}
}

func TestInvalidConfigNamesTheField(t *testing.T) {
	tests := []struct {
		name string
		body string
		want string
	}{
		{name: "empty host", body: configJSON("", 5308, "DL1ABC", "key", 1), want: "host is empty"},
		{name: "blank host", body: configJSON("   ", 5308, "DL1ABC", "key", 1), want: "host is empty"},
		{name: "host type", body: `{"host":1,"port":5308,"callsign":"DL1ABC","authKey":"key","talkGroup":1}`, want: "host has the wrong type"},
		{name: "empty callsign", body: configJSON("127.0.0.1", 5308, "", "key", 1), want: "callsign is empty"},
		{name: "callsign type", body: `{"host":"127.0.0.1","port":5308,"callsign":1,"authKey":"key","talkGroup":1}`, want: "callsign has the wrong type"},
		{name: "empty auth key", body: configJSON("127.0.0.1", 5308, "DL1ABC", "", 1), want: "authKey is empty"},
		{name: "whitespace auth key", body: configJSON("127.0.0.1", 5308, "DL1ABC", " \t", 1), want: "authKey is empty"},
		{name: "auth key type", body: `{"host":"127.0.0.1","port":5308,"callsign":"DL1ABC","authKey":1,"talkGroup":1}`, want: "authKey has the wrong type"},
		{name: "port zero", body: configJSON("127.0.0.1", 0, "DL1ABC", "key", 1), want: "port is invalid"},
		{name: "port negative", body: configJSON("127.0.0.1", -1, "DL1ABC", "key", 1), want: "port is invalid"},
		{name: "port too high", body: configJSON("127.0.0.1", 65536, "DL1ABC", "key", 1), want: "port is invalid"},
		{name: "port type", body: `{"host":"127.0.0.1","port":"5308","callsign":"DL1ABC","authKey":"key","talkGroup":1}`, want: "port has the wrong type"},
		{name: "port fraction", body: `{"host":"127.0.0.1","port":5308.5,"callsign":"DL1ABC","authKey":"key","talkGroup":1}`, want: "port is invalid"},
		{name: "talk group zero", body: configJSON("127.0.0.1", 5308, "DL1ABC", "key", 0), want: "talkGroup is invalid"},
		{name: "talk group negative", body: configJSON("127.0.0.1", 5308, "DL1ABC", "key", -3), want: "talkGroup is invalid"},
		{name: "talk group type", body: `{"host":"127.0.0.1","port":5308,"callsign":"DL1ABC","authKey":"key","talkGroup":"20"}`, want: "talkGroup has the wrong type"},
		{name: "bad callsign", body: configJSON("127.0.0.1", 5308, "HELLO", "key", 1), want: "callsign is invalid"},
	}
	for _, tt := range tests {
		t.Run(tt.name, func(t *testing.T) {
			path := filepath.Join(t.TempDir(), "funknetz.json")
			if err := os.WriteFile(path, []byte(tt.body), 0o600); err != nil {
				t.Fatal(err)
			}
			before, err := os.ReadFile(path)
			if err != nil {
				t.Fatal(err)
			}
			_, err = station.New(station.Options{ConfigPath: path})
			if err == nil {
				t.Fatal("New() error = nil, want a field rejection")
			}
			if err.Error() != tt.want {
				t.Fatalf("New() error = %q, want %q", err.Error(), tt.want)
			}
			after, err := os.ReadFile(path)
			if err != nil {
				t.Fatal(err)
			}
			if string(after) != string(before) {
				t.Fatalf("file = %q, want it left untouched", after)
			}
		})
	}
}

func TestBrokenConfigSaysTheFileCouldNotBeRead(t *testing.T) {
	path := filepath.Join(t.TempDir(), "funknetz.json")
	if err := os.WriteFile(path, []byte("{"), 0o600); err != nil {
		t.Fatal(err)
	}
	_, err := station.New(station.Options{ConfigPath: path})
	if err == nil {
		t.Fatal("New() error = nil, want a read failure")
	}
	if err.Error() != "could not be read" {
		t.Fatalf("New() error = %q, want %q", err.Error(), "could not be read")
	}
	if strings.Contains(err.Error(), "callsign") {
		t.Fatalf("New() error = %q, want no field name", err.Error())
	}
}

func TestCallsignIsTrimmedAndUppercased(t *testing.T) {
	path := filepath.Join(t.TempDir(), "funknetz.json")
	body := configJSON("  127.0.0.1  ", 5308, "  dl1abc-r  ", "a b", 20)
	if err := os.WriteFile(path, []byte(body), 0o600); err != nil {
		t.Fatal(err)
	}
	st, err := station.New(station.Options{ConfigPath: path})
	if err != nil {
		t.Fatal(err)
	}
	got := st.State()
	if got.Callsign != "DL1ABC-R" {
		t.Fatalf("Callsign = %q, want DL1ABC-R", got.Callsign)
	}
	if got.TalkGroup != 20 {
		t.Fatalf("TalkGroup = %d, want 20", got.TalkGroup)
	}
	if got.Connection != "Disconnected" || got.Detail != "Idle" || got.Talker != "" || got.Transmitting {
		t.Fatalf("State = %+v, want Disconnected, Idle, no talker", got)
	}
}

func configJSON(host string, port int, callsign, authKey string, talkGroup int) string {
	body, err := jsonv2.Marshal(map[string]any{
		"host":      host,
		"port":      port,
		"callsign":  callsign,
		"authKey":   authKey,
		"talkGroup": talkGroup,
	})
	if err != nil {
		panic(err)
	}
	return string(body)
}