package validators

import (
	"strings"
	"testing"

	"gitea.maximumdirect.net/eric/notarius/internal/core/artifacts"
	"gitea.maximumdirect.net/eric/notarius/internal/framework/contracts"
)

func TestApproved(t *testing.T) {
	decision := Approved(7)

	if decision.CandidateIndex != 7 {
		t.Fatalf("CandidateIndex = %d, want 7", decision.CandidateIndex)
	}
	if !decision.Approved {
		t.Fatal("Approved = false, want true")
	}
	if decision.ReasonCode != ReasonApproved {
		t.Fatalf("ReasonCode = %q, want %q", decision.ReasonCode, ReasonApproved)
	}
	if decision.Message != "approved" {
		t.Fatalf("Message = %q, want approved", decision.Message)
	}
}

func TestRejectedTrimsReasonAndMessage(t *testing.T) {
	decision := Rejected(3, " invalid ", "\tmessage\n")

	if decision.CandidateIndex != 3 {
		t.Fatalf("CandidateIndex = %d, want 3", decision.CandidateIndex)
	}
	if decision.Approved {
		t.Fatal("Approved = true, want false")
	}
	if decision.ReasonCode != "invalid" {
		t.Fatalf("ReasonCode = %q, want invalid", decision.ReasonCode)
	}
	if decision.Message != "message" {
		t.Fatalf("Message = %q, want message", decision.Message)
	}
}

func TestEnforceDecisionCardinalityAllowsNonZeroCandidateIndices(t *testing.T) {
	candidates := []artifacts.Candidate{{Index: 4}, {Index: 8}}
	decisions := []contracts.ValidationDecision{Approved(8), Approved(4)}

	if err := EnforceDecisionCardinality(candidates, decisions); err != nil {
		t.Fatalf("EnforceDecisionCardinality() error = %v, want nil", err)
	}
}

func TestEnforceDecisionCardinalityAllowsEmptyInputs(t *testing.T) {
	if err := EnforceDecisionCardinality(nil, nil); err != nil {
		t.Fatalf("EnforceDecisionCardinality() error = %v, want nil", err)
	}
}

func TestEnforceDecisionCardinalityRejectsUnknownDecisionIndex(t *testing.T) {
	err := EnforceDecisionCardinality(
		[]artifacts.Candidate{{Index: 1}},
		[]contracts.ValidationDecision{Approved(2)},
	)

	assertCardinalityError(t, err, "unknown candidate index 2")
}

func TestEnforceDecisionCardinalityRejectsDuplicateDecisionIndex(t *testing.T) {
	err := EnforceDecisionCardinality(
		[]artifacts.Candidate{{Index: 1}, {Index: 2}},
		[]contracts.ValidationDecision{Approved(1), Approved(1)},
	)

	assertCardinalityError(t, err, "duplicate decision")
}

func TestEnforceDecisionCardinalityRejectsMissingDecisionIndex(t *testing.T) {
	err := EnforceDecisionCardinality(
		[]artifacts.Candidate{{Index: 1}, {Index: 2}},
		[]contracts.ValidationDecision{Approved(1)},
	)

	assertCardinalityError(t, err, "1 decisions for 2 candidates")
}

func TestEnforceDecisionCardinalityRejectsDuplicateCandidateIndex(t *testing.T) {
	err := EnforceDecisionCardinality(
		[]artifacts.Candidate{{Index: 1}, {Index: 1}},
		[]contracts.ValidationDecision{Approved(1), Approved(1)},
	)

	assertCardinalityError(t, err, "candidate index 1 is duplicated")
}

func assertCardinalityError(t *testing.T, err error, want string) {
	t.Helper()

	if err == nil {
		t.Fatal("EnforceDecisionCardinality() error = nil, want error")
	}
	if !strings.Contains(err.Error(), want) {
		t.Fatalf("EnforceDecisionCardinality() error = %q, want substring %q", err.Error(), want)
	}
}