package config

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

func writeTmp(t *testing.T, body string) string {
	t.Helper()
	p := filepath.Join(t.TempDir(), "c.toml")
	if err := os.WriteFile(p, []byte(body), 0o600); err != nil {
		t.Fatal(err)
	}
	return p
}

const minimal = `
agent_id = "host-1"
state_dir = "/tmp/x"

[server]
url = "http://localhost"
token = "t"

[[checks]]
id = "c1"
command = ["true"]
interval = "10s"
timeout = "5s"
`

func TestLoadMinimal(t *testing.T) {
	c, err := Load(writeTmp(t, minimal))
	if err != nil {
		t.Fatal(err)
	}
	if c.Mode != "hybrid" {
		t.Errorf("default mode: %q", c.Mode)
	}
	if c.Server.HeartbeatInterval.Duration == 0 {
		t.Error("default heartbeat not applied")
	}
	if c.Checks[0].NotificationOwner != "server" {
		t.Errorf("default notification_owner: %q", c.Checks[0].NotificationOwner)
	}
}

func TestValidateBadID(t *testing.T) {
	body := minimal + "\n"
	_, err := Load(writeTmp(t, body[:0]+`
agent_id = "bad id!"
state_dir = "/tmp/x"
[server]
url = "http://localhost"
token = "t"
[[checks]]
id = "c1"
command = ["true"]
interval = "10s"
timeout = "5s"
`))
	if err == nil {
		t.Fatal("expected error for bad agent_id")
	}
}

func TestValidateTimeoutExceedsInterval(t *testing.T) {
	_, err := Load(writeTmp(t, `
agent_id = "x"
state_dir = "/tmp/x"
[server]
url = "http://localhost"
token = "t"
[[checks]]
id = "c1"
command = ["true"]
interval = "5s"
timeout = "10s"
`))
	if err == nil {
		t.Fatal("expected error for timeout > interval")
	}
}

func TestPrometheusOnlyAllowsMissingServer(t *testing.T) {
	c, err := Load(writeTmp(t, `
mode = "prometheus_only"
state_dir = "/tmp/x"
[[checks]]
id = "c1"
command = ["true"]
interval = "10s"
timeout = "5s"
`))
	if err != nil {
		t.Fatal(err)
	}
	if c.PushesToServer() {
		t.Fatal("prometheus_only must not push")
	}
}

func TestPushOnlyRequiresServer(t *testing.T) {
	_, err := Load(writeTmp(t, `
mode = "push_only"
state_dir = "/tmp/x"
[[checks]]
id = "c1"
command = ["true"]
interval = "10s"
timeout = "5s"
`))
	if err == nil {
		t.Fatal("push_only must require server.url/token")
	}
}

func TestExposesMetricsGate(t *testing.T) {
	cases := []struct {
		mode    string
		enabled bool
		want    bool
	}{
		{"hybrid", true, true},
		{"hybrid", false, false},
		{"prometheus_only", true, true},
		{"push_only", true, false},
	}
	for _, tc := range cases {
		c := &Config{Mode: tc.mode, Metrics: MetricsConfig{Enabled: tc.enabled}}
		if got := c.ExposesMetrics(); got != tc.want {
			t.Errorf("mode=%s enabled=%v want=%v got=%v", tc.mode, tc.enabled, tc.want, got)
		}
	}
}

func TestValidateDuplicateCheckID(t *testing.T) {
	_, err := Load(writeTmp(t, `
agent_id = "x"
state_dir = "/tmp/x"
[server]
url = "http://localhost"
token = "t"
[[checks]]
id = "c1"
command = ["true"]
interval = "10s"
timeout = "5s"
[[checks]]
id = "c1"
command = ["true"]
interval = "10s"
timeout = "5s"
`))
	if err == nil {
		t.Fatal("expected duplicate id error")
	}
}