// SPDX-License-Identifier: MIT

package iprule

import (
	"context"
	"strings"
	"testing"

	"prx/internal/execx"
)

func TestParseRules(t *testing.T) {
	out := `0:	from all lookup local
50:	from all to 198.51.100.0/24 lookup 102
100:	from all fwmark 0x100 lookup 100
32766:	from all lookup main
32767:	from all lookup default
`
	entries := parseRules(out)
	if len(entries) != 5 {
		t.Fatalf("expected 5 entries, got %d", len(entries))
	}
	if !entries[2].HasMark || entries[2].Mark != 0x100 || entries[2].Table != 100 || entries[2].Priority != 100 {
		t.Errorf("mark entry parsed wrong: %+v", entries[2])
	}
	if !entries[1].HasTo || entries[1].To != "198.51.100.0/24" || entries[1].Table != 102 {
		t.Errorf("bypass entry parsed wrong: %+v", entries[1])
	}
}

func ruleRunner(out string) (*execx.Fake, *[]execx.Call) {
	f := &execx.Fake{Handler: func(name string, args []string, _ []byte) (execx.Result, error) {
		if len(args) >= 2 && args[len(args)-2] == "rule" && args[len(args)-1] == "show" {
			return execx.Result{Stdout: []byte(out)}, nil
		}
		return execx.Result{}, nil
	}}
	return f, &f.Calls
}

func TestRuleExists(t *testing.T) {
	f, _ := ruleRunner("100:\tfrom all fwmark 0x100 lookup 100\n")
	ok, err := RuleExists(context.Background(), f, Spec{Family: 4, Mark: 0x100, Table: 100, Priority: 100})
	if err != nil || !ok {
		t.Fatalf("RuleExists = %v, %v", ok, err)
	}
	ok, err = RuleExists(context.Background(), f, Spec{Family: 4, Mark: 0x100, Table: 100, Priority: 200})
	if err != nil || ok {
		t.Fatalf("expected absent, got %v, %v", ok, err)
	}
}

func TestEnsureRuleAddsWhenMissing(t *testing.T) {
	f, calls := ruleRunner("")
	changed, err := EnsureRule(context.Background(), f, Spec{Family: 4, Mark: 0x100, Table: 100, Priority: 100})
	if err != nil || !changed {
		t.Fatalf("EnsureRule = %v, %v", changed, err)
	}
	if !hasCall(*calls, "ip", "rule", "add", "fwmark", "0x100", "lookup", "100", "priority", "100") {
		t.Fatalf("expected add call, got %+v", *calls)
	}
}

func TestEnsureRuleNoopWhenPresent(t *testing.T) {
	f, calls := ruleRunner("100:\tfrom all fwmark 0x100 lookup 100\n")
	changed, err := EnsureRule(context.Background(), f, Spec{Family: 4, Mark: 0x100, Table: 100, Priority: 100})
	if err != nil || changed {
		t.Fatalf("expected no-op, got %v, %v", changed, err)
	}
	for _, c := range *calls {
		if len(c.Args) >= 2 && c.Args[1] == "add" {
			t.Fatalf("unexpected add call: %+v", c)
		}
	}
}

func TestRemoveRulesByTable(t *testing.T) {
	out := `50:	from all to 198.51.100.0/24 lookup 102
100:	from all fwmark 0x100 lookup 100
110:	from all fwmark 0x100 lookup 100
`
	f, calls := ruleRunner(out)
	n, err := RemoveRulesByTable(context.Background(), f, 4, 100)
	if err != nil {
		t.Fatalf("RemoveRulesByTable: %v", err)
	}
	if n != 2 {
		t.Fatalf("removed %d, want 2", n)
	}
	for _, c := range *calls {
		if len(c.Args) >= 2 && c.Args[1] == "del" && !strings.Contains(strings.Join(c.Args, " "), "lookup 100") {
			t.Fatalf("deleted wrong rule: %+v", c)
		}
	}
}

func hasCall(calls []execx.Call, name string, args ...string) bool {
	for _, c := range calls {
		if c.Name != name || len(c.Args) != len(args) {
			continue
		}
		match := true
		for i := range args {
			if c.Args[i] != args[i] {
				match = false
				break
			}
		}
		if match {
			return true
		}
	}
	return false
}