package rules_test

import (
	"testing"
	"testing/fstest"

	"github.com/netcell-it/deklarix/internal/rules"
)

func TestLoadRejectsMissingID(t *testing.T) {
	fsys := fstest.MapFS{
		"bad.yaml": &fstest.MapFile{Data: []byte("version: 1\ntitel: x\nschwere: hoch\n")},
	}
	if _, err := rules.Load(fsys); err == nil {
		t.Fatal("expected error for rule without id, got nil")
	}
}

func TestLoadRejectsMissingVersion(t *testing.T) {
	fsys := fstest.MapFS{
		"bad.yaml": &fstest.MapFile{Data: []byte("id: WK-999\ntitel: x\nschwere: hoch\n")},
	}
	if _, err := rules.Load(fsys); err == nil {
		t.Fatal("expected error for rule without version, got nil")
	}
}

func TestLoadRejectsMissingJurisdiction(t *testing.T) {
	fsys := fstest.MapFS{
		"bad.yaml": &fstest.MapFile{Data: []byte("id: WK-999\nversion: 1\ntitel: x\nschwere: hoch\n")},
	}
	if _, err := rules.Load(fsys); err == nil {
		t.Fatal("expected error for rule without land (jurisdiction), got nil")
	}
}

func TestLoadRejectsDuplicateID(t *testing.T) {
	fsys := fstest.MapFS{
		"a.yaml": &fstest.MapFile{Data: []byte("id: WK-999\nversion: 1\nland: DE\ntitel: x\nschwere: hoch\n")},
		"b.yaml": &fstest.MapFile{Data: []byte("id: WK-999\nversion: 2\nland: DE\ntitel: y\nschwere: hoch\n")},
	}
	if _, err := rules.Load(fsys); err == nil {
		t.Fatal("expected error for duplicate rule id, got nil")
	}
}

func TestLoadIgnoresNonYAMLFiles(t *testing.T) {
	fsys := fstest.MapFS{
		"a.yaml":    &fstest.MapFile{Data: []byte("id: WK-999\nversion: 1\nland: DE\ntitel: x\nschwere: hoch\n")},
		"README.md": &fstest.MapFile{Data: []byte("not a rule")},
	}
	got, err := rules.Load(fsys)
	if err != nil {
		t.Fatalf("Load: %v", err)
	}
	if len(got) != 1 {
		t.Fatalf("expected 1 rule, got %d", len(got))
	}
}

func TestConditionMatches(t *testing.T) {
	yes := true
	no := false

	cases := []struct {
		name string
		cond rules.Condition
		fact rules.Facts
		want bool
	}{
		{
			name: "consideration list matches",
			cond: rules.Condition{Consideration: []rules.Consideration{rules.ConsiderationPaid}},
			fact: rules.Facts{Consideration: rules.ConsiderationPaid},
			want: true,
		},
		{
			name: "consideration list does not match",
			cond: rules.Condition{Consideration: []rules.Consideration{rules.ConsiderationPaid}},
			fact: rules.Facts{Consideration: rules.ConsiderationNone},
			want: false,
		},
		{
			name: "disclosure present must match",
			cond: rules.Condition{DisclosurePresent: &no},
			fact: rules.Facts{DisclosurePresent: true},
			want: false,
		},
		{
			name: "unset fields impose no constraint",
			cond: rules.Condition{},
			fact: rules.Facts{Consideration: rules.ConsiderationUnclear},
			want: true,
		},
		{
			name: "all constraints must hold (AND)",
			cond: rules.Condition{
				Consideration:       []rules.Consideration{rules.ConsiderationPaid},
				DisclosurePresent:   &yes,
				DisclosureBeforeCut: &no,
			},
			fact: rules.Facts{Consideration: rules.ConsiderationPaid, DisclosurePresent: true, DisclosureBeforeCut: false},
			want: true,
		},
	}

	for _, tc := range cases {
		t.Run(tc.name, func(t *testing.T) {
			if got := tc.cond.Matches(tc.fact); got != tc.want {
				t.Fatalf("Matches() = %v, want %v", got, tc.want)
			}
		})
	}
}

func TestEvaluateFiltersByJurisdiction(t *testing.T) {
	rule := rules.Rule{
		ID:           "WK-TEST",
		Version:      1,
		Jurisdiction: "AT",
		Condition:    rules.Condition{Consideration: []rules.Consideration{rules.ConsiderationPaid}},
		Severity:     rules.SeverityHigh,
	}
	fact := rules.Facts{Jurisdiction: "DE", Consideration: rules.ConsiderationPaid}

	findings, needsClarification := rules.Evaluate([]rules.Rule{rule}, fact)
	if needsClarification {
		t.Fatal("needsClarification = true, want false")
	}
	if len(findings) != 0 {
		t.Fatalf("expected no findings for a rule from a different jurisdiction, got %v", findings)
	}
}