// SPDX-License-Identifier: MIT

package config

import (
	"path/filepath"
	"testing"
)

func TestDefaultIsValid(t *testing.T) {
	if err := Default().Validate(); err != nil {
		t.Fatalf("default config invalid: %v", err)
	}
}

func TestParseCIDR(t *testing.T) {
	tests := []struct {
		in   string
		want string
		bad  bool
	}{
		{"192.168.1.0/24", "192.168.1.0/24", false},
		{"1.2.3.4", "1.2.3.4/32", false},
		{"2001:db8::/32", "2001:db8::/32", false},
		{"::1", "::1/128", false},
		{"10.0.0.0/8", "10.0.0.0/8", false},
		{"not-an-ip", "", true},
		{"", "", true},
	}
	for _, tt := range tests {
		got, err := ParseCIDR(tt.in)
		if tt.bad {
			if err == nil {
				t.Errorf("ParseCIDR(%q): expected error", tt.in)
			}
			continue
		}
		if err != nil {
			t.Errorf("ParseCIDR(%q): %v", tt.in, err)
			continue
		}
		if got != tt.want {
			t.Errorf("ParseCIDR(%q) = %q, want %q", tt.in, got, tt.want)
		}
	}
}

func TestAddRemoveExtraCIDR(t *testing.T) {
	c := Default()
	changed, err := c.AddExtraCIDR("203.0.113.7")
	if err != nil || !changed {
		t.Fatalf("AddExtraCIDR: changed=%v err=%v", changed, err)
	}
	changed, err = c.AddExtraCIDR("203.0.113.7/32")
	if err != nil || changed {
		t.Fatalf("duplicate should be a no-op: changed=%v err=%v", changed, err)
	}
	if _, err := c.AddExtraCIDR("0.0.0.0/0"); err == nil {
		t.Fatal("expected refusal to bypass default route")
	}
	changed, err = c.RemoveExtraCIDR("203.0.113.7")
	if err != nil || !changed {
		t.Fatalf("RemoveExtraCIDR: changed=%v err=%v", changed, err)
	}
}

func TestValidateRejectsBadValues(t *testing.T) {
	cases := map[string]func(*Config){
		"zero mark":       func(c *Config) { c.Marks.InboundMark = 0 },
		"reserved table":  func(c *Config) { c.Routing.TableV4 = 254 },
		"bad priority":    func(c *Config) { c.Routing.PriorityV4 = 70000 },
		"bad cidr":        func(c *Config) { c.Bypass.ExtraCIDRs = []string{"nope"} },
		"relative state":  func(c *Config) { c.State.Path = "state.json" },
		"empty type":      func(c *Config) { c.Engine.Type = "" },
		"bad service":     func(c *Config) { c.Engine.ServiceName = "bad name!" },
		"bad wan iface":   func(c *Config) { c.Network.WANInterface = "bad iface" },
		"bad gateway":     func(c *Config) { c.Network.WANGateway = "nope" },
		"relative engine": func(c *Config) { c.Engine.ConfigPath = "rel.json" },
	}
	for name, mutate := range cases {
		c := Default()
		mutate(c)
		if err := c.Validate(); err == nil {
			t.Errorf("case %q: expected validation error", name)
		}
	}
}

func TestSaveLoadRoundTrip(t *testing.T) {
	dir := t.TempDir()
	path := filepath.Join(dir, "prx", "config.json")
	c := Default()
	if changed, _ := c.AddExtraCIDR("198.51.100.0/24"); !changed {
		t.Fatal("expected change")
	}
	if err := Save(path, c); err != nil {
		t.Fatalf("Save: %v", err)
	}
	got, err := Load(path)
	if err != nil {
		t.Fatalf("Load: %v", err)
	}
	if len(got.Bypass.ExtraCIDRs) != 1 || got.Bypass.ExtraCIDRs[0] != "198.51.100.0/24" {
		t.Fatalf("unexpected extra cidrs: %+v", got.Bypass.ExtraCIDRs)
	}
	if got.Marks.InboundMark != DefaultMark {
		t.Fatalf("mark not preserved: %x", got.Marks.InboundMark)
	}
}

func TestLoadMissingReturnsDefault(t *testing.T) {
	got, err := Load(filepath.Join(t.TempDir(), "absent.json"))
	if err != nil {
		t.Fatalf("Load: %v", err)
	}
	if got.Engine.Type != "sing-box" {
		t.Fatalf("expected default engine, got %q", got.Engine.Type)
	}
}

func TestAddDomainValidatesAndDedupes(t *testing.T) {
	c := Default()
	if _, err := c.AddDomain("not a domain"); err == nil {
		t.Fatal("expected error for invalid domain")
	}
	if _, err := c.AddDomain(""); err == nil {
		t.Fatal("expected error for empty domain")
	}
	changed, err := c.AddDomain("Example.com")
	if err != nil || !changed {
		t.Fatalf("AddDomain: changed=%v err=%v", changed, err)
	}
	if changed, _ := c.AddDomain("example.com"); changed {
		t.Fatal("duplicate domain should be a no-op (case-insensitive)")
	}
	if changed, _ := c.AddDomain("*.wild.example.com"); !changed {
		t.Fatal("wildcard domain should be accepted")
	}
	if !c.RemoveDomain("EXAMPLE.COM") {
		t.Fatal("RemoveDomain should be case-insensitive")
	}
}

func TestValidDomain(t *testing.T) {
	valid := []string{"example.com", "a.b.c.example.org", "*.example.com", "xn--bcher-kva.example"}
	for _, d := range valid {
		if !ValidDomain(d) {
			t.Errorf("ValidDomain(%q) = false, want true", d)
		}
	}
	invalid := []string{"", "no_dots", "trailing-.com", "-leading.com", "sp ace.com", "*.", "a..b.com"}
	for _, d := range invalid {
		if ValidDomain(d) {
			t.Errorf("ValidDomain(%q) = true, want false", d)
		}
	}
}

func TestHealthProbeValidation(t *testing.T) {
	ok := Default()
	if err := ok.Validate(); err != nil {
		t.Fatalf("default probe rejected: %v", err)
	}
	disabled := Default()
	disabled.Health.Probe = ""
	if err := disabled.Validate(); err != nil {
		t.Fatalf("empty probe should disable the check: %v", err)
	}
	for _, bad := range []string{"nope", ":443", "1.1.1.1:0", "1.1.1.1:99999"} {
		c := Default()
		c.Health.Probe = bad
		if err := c.Validate(); err == nil {
			t.Errorf("Health.Probe %q: expected validation error", bad)
		}
	}
}

func TestCheckTableIDRejectsReserved(t *testing.T) {
	for _, id := range []int{0, 253, 254, 255, -1, MaxTableID + 1} {
		if err := CheckTableID("table", id); err == nil {
			t.Errorf("CheckTableID(%d): expected error", id)
		}
	}
	if err := CheckTableID("table", 100); err != nil {
		t.Errorf("CheckTableID(100): unexpected error: %v", err)
	}
}

func TestWANGateway6Validation(t *testing.T) {
	c := Default()
	c.Network.WANGateway6 = "2001:db8::1"
	if err := c.Validate(); err != nil {
		t.Fatalf("valid IPv6 gateway rejected: %v", err)
	}
	c.Network.WANGateway6 = "192.168.1.1"
	if err := c.Validate(); err == nil {
		t.Fatal("IPv4 address in wan_gateway6 should be rejected")
	}
}