package smtp2shoutrrr

import (
	"bytes"
	"log/slog"
	"os"
	"path/filepath"
	"testing"

	"github.com/stretchr/testify/require"
)

// credentials is prepended to fixtures that are not themselves about
// authentication, so each one still fails (or passes) for the reason it names
// rather than for the credentials it does not mention.
const credentials = `
Username = "user"
Password = "secret"
`

func writeConfig(t *testing.T, contents string) string {
	t.Helper()

	path := filepath.Join(t.TempDir(), "config.toml")
	require.NoError(t, os.WriteFile(path, []byte(contents), 0o600))

	return path
}

func TestLoadConfig(t *testing.T) {
	path := writeConfig(t, `
Port = 2525
Username = "user"
Password = "secret"

[[Recipients]]
Addresses = ["user@example.com"]
Targets = ["ntfy://ntfy.sh/topic"]

[[Recipients]]
Addresses = ["legacy@example.com"]
Target = "ntfy://ntfy.sh/legacy"

[CatchAll]
Targets = ["ntfy://ntfy.sh/catch-all"]
`)

	config, err := LoadConfig(path)
	require.NoError(t, err)

	require.Equal(t, 2525, config.Port)
	require.Equal(t, "user", config.Username)
	require.Equal(t, "secret", config.Password)

	require.Len(t, config.Recipients, 2)
	require.Equal(t, []string{"user@example.com"}, config.Recipients[0].Addresses)
	require.Equal(t, []string{"ntfy://ntfy.sh/topic"}, config.Recipients[0].Targets)
	require.Equal(t, "ntfy://ntfy.sh/legacy", config.Recipients[1].Target)

	require.NotNil(t, config.CatchAll)
	require.Equal(t, []string{"ntfy://ntfy.sh/catch-all"}, config.CatchAll.Targets)
}

func TestLoadConfigAppliesDefaults(t *testing.T) {
	path := writeConfig(t, credentials+`
[[Recipients]]
Addresses = ["user@example.com"]
Targets = ["ntfy://ntfy.sh/topic"]
`)

	config, err := LoadConfig(path)
	require.NoError(t, err)

	require.Equal(t, 11125, config.Port)
	require.Nil(t, config.CatchAll)

	// Credentials deliberately have no default; see
	// TestLoadConfigRejectsUnsetCredentials.
	require.Equal(t, "user", config.Username)
	require.Equal(t, "secret", config.Password)
}

// Regression: unset credentials used to fall back to username/password with
// only a warning, so a config naming nothing but a port and its recipients
// left the AUTH gate open to the most obvious guess there is — and the README
// promised an authentication that had never been configured.
func TestLoadConfigRejectsUnsetCredentials(t *testing.T) {
	recipient := `
[[Recipients]]
Addresses = ["user@example.com"]
Targets = ["ntfy://ntfy.sh/topic"]
`

	for name, contents := range map[string]string{
		"neither credential": recipient,
		"no Username":        `Password = "secret"` + recipient,
		"no Password":        `Username = "user"` + recipient,
		"empty Username":     `Username = ""` + "\n" + `Password = "secret"` + recipient,
		"empty Password":     `Username = "user"` + "\n" + `Password = ""` + recipient,
	} {
		t.Run(name, func(t *testing.T) {
			config, err := LoadConfig(writeConfig(t, contents))
			require.Error(t, err)
			require.Nil(t, config)
		})
	}
}

func TestLoadConfigMissingFile(t *testing.T) {
	_, err := LoadConfig(filepath.Join(t.TempDir(), "does-not-exist.toml"))
	require.Error(t, err)
}

func TestLoadConfigInvalidTOML(t *testing.T) {
	_, err := LoadConfig(writeConfig(t, "Port = "))
	require.Error(t, err)
}

func TestLoadConfigRejectsUnusableConfigurations(t *testing.T) {
	// A TOML decode ignores unknown keys, so each of these parses cleanly and
	// would otherwise start a server that forwards nothing.
	for name, contents := range map[string]string{
		"mistyped recipients table": `
[[Recipient]]
Addresses = ["user@example.com"]
Targets = ["ntfy://ntfy.sh/topic"]
`,
		"mistyped addresses key": `
[[Recipients]]
Adresses = ["user@example.com"]
Targets = ["ntfy://ntfy.sh/topic"]
`,
		"recipient without targets": `
[[Recipients]]
Addresses = ["user@example.com"]
`,
		"recipient with only unparseable targets": `
[[Recipients]]
Addresses = ["user@example.com"]
Targets = ["://invalid-url"]
`,
		"recipient whose target is not a URL at all": `
[[Recipients]]
Addresses = ["user@example.com"]
Targets = ["this is not a url at all"]
`,
		"catch-all without targets": `
[CatchAll]
Addresses = ["user@example.com"]
`,
		"empty configuration": `
Port = 2525
`,
	} {
		t.Run(name, func(t *testing.T) {
			_, err := LoadConfig(writeConfig(t, credentials+contents))
			require.Error(t, err)
		})
	}
}

func TestLoadConfigAcceptsCatchAllOnly(t *testing.T) {
	config, err := LoadConfig(writeConfig(t, credentials+`
[CatchAll]
Targets = ["ntfy://ntfy.sh/catch-all"]
`))
	require.NoError(t, err)
	require.Empty(t, config.Recipients)
	require.NotNil(t, config.CatchAll)
}

// A mistyped table name is silently dropped by the decoder. It is only fatal
// when nothing else is configured, so with a catch-all present the warning is
// the sole signal that the block was ignored.
func TestLoadConfigWarnsAboutIgnoredKeys(t *testing.T) {
	var logged bytes.Buffer
	restore := slog.Default()
	slog.SetDefault(slog.New(slog.NewTextHandler(&logged, &slog.HandlerOptions{Level: slog.LevelWarn})))
	t.Cleanup(func() { slog.SetDefault(restore) })

	config, err := LoadConfig(writeConfig(t, credentials+`
[[Recipient]]
Addresses = ["user@example.com"]
Targets = ["ntfy://ntfy.sh/topic"]

[CatchAll]
Targets = ["ntfy://ntfy.sh/catch-all"]
`))
	require.NoError(t, err)
	require.Empty(t, config.Recipients, "the mistyped table is still ignored")
	require.Contains(t, logged.String(), "ignoring unknown key in config file")
	require.Contains(t, logged.String(), "Recipient")
}