package app

import (
	"encoding/json"
	"net/http"
	"net/http/httptest"
	"path/filepath"
	"strings"
	"testing"
)

func withTransportPolicyMutationTestPaths(t *testing.T) {
	t.Helper()
	tmp := t.TempDir()

	prevClients := transportClientsStatePath
	prevIfaces := transportInterfacesStatePath
	prevPolicy := transportPolicyStatePath
	prevPolicySnap := transportPolicySnapshotPath
	prevPlan := transportPolicyPlanStatePath
	prevRuntime := transportPolicyRuntimeStatePath
	prevRuntimeSnap := transportPolicyRuntimeSnapPath
	prevOwners := transportOwnershipStatePath
	prevConflicts := transportConflictsStatePath
	prevIdem := transportPolicyIdempotencyStatePath

	transportClientsStatePath = filepath.Join(tmp, "transport-clients.json")
	transportInterfacesStatePath = filepath.Join(tmp, "transport-interfaces.json")
	transportPolicyStatePath = filepath.Join(tmp, "transport-policies.json")
	transportPolicySnapshotPath = filepath.Join(tmp, "transport-policies.prev.json")
	transportPolicyPlanStatePath = filepath.Join(tmp, "transport-policies.plan.json")
	transportPolicyRuntimeStatePath = filepath.Join(tmp, "transport-policies.runtime.json")
	transportPolicyRuntimeSnapPath = filepath.Join(tmp, "transport-policies.runtime.prev.json")
	transportOwnershipStatePath = filepath.Join(tmp, "transport-ownership.json")
	transportConflictsStatePath = filepath.Join(tmp, "transport-conflicts.json")
	transportPolicyIdempotencyStatePath = filepath.Join(tmp, "transport-policy-idempotency.json")

	t.Cleanup(func() {
		transportClientsStatePath = prevClients
		transportInterfacesStatePath = prevIfaces
		transportPolicyStatePath = prevPolicy
		transportPolicySnapshotPath = prevPolicySnap
		transportPolicyPlanStatePath = prevPlan
		transportPolicyRuntimeStatePath = prevRuntime
		transportPolicyRuntimeSnapPath = prevRuntimeSnap
		transportOwnershipStatePath = prevOwners
		transportConflictsStatePath = prevConflicts
		transportPolicyIdempotencyStatePath = prevIdem
	})
}

func TestTransportPolicyApplyIdempotencyReplay(t *testing.T) {
	withTransportPolicyMutationTestPaths(t)

	body := `{"base_revision":0,"intents":[]}`
	req1 := httptest.NewRequest(http.MethodPost, "/api/v1/transport/policies/apply", strings.NewReader(body))
	req1.Header.Set("Idempotency-Key", "apply-replay-1")
	rec1 := httptest.NewRecorder()
	handleTransportPoliciesApplyExec(rec1, req1)
	if rec1.Code != http.StatusOK {
		t.Fatalf("unexpected status: %d body=%s", rec1.Code, rec1.Body.String())
	}
	var resp1 TransportPolicyResponse
	if err := json.Unmarshal(rec1.Body.Bytes(), &resp1); err != nil {
		t.Fatalf("decode first apply response: %v", err)
	}
	if !resp1.OK || resp1.PolicyRevision != 1 || strings.TrimSpace(resp1.ApplyID) == "" {
		t.Fatalf("unexpected first apply response: %#v", resp1)
	}

	req2 := httptest.NewRequest(http.MethodPost, "/api/v1/transport/policies/apply", strings.NewReader(body))
	req2.Header.Set("Idempotency-Key", "apply-replay-1")
	rec2 := httptest.NewRecorder()
	handleTransportPoliciesApplyExec(rec2, req2)
	if rec2.Code != http.StatusOK {
		t.Fatalf("unexpected replay status: %d body=%s", rec2.Code, rec2.Body.String())
	}
	var resp2 TransportPolicyResponse
	if err := json.Unmarshal(rec2.Body.Bytes(), &resp2); err != nil {
		t.Fatalf("decode replay apply response: %v", err)
	}
	if !resp2.OK || resp2.PolicyRevision != 1 || resp2.ApplyID != resp1.ApplyID {
		t.Fatalf("unexpected replay response: first=%#v second=%#v", resp1, resp2)
	}

	current := loadTransportPolicyState()
	if current.Revision != 1 {
		t.Fatalf("policy revision must remain 1 after replay, got %d", current.Revision)
	}
	idem := loadTransportPolicyIdempotencyState()
	if len(idem.Items) != 1 {
		t.Fatalf("expected one idempotency record, got %#v", idem)
	}
}

func TestTransportPolicyApplyIdempotencyRejectsPayloadReuse(t *testing.T) {
	withTransportPolicyMutationTestPaths(t)

	req1 := httptest.NewRequest(http.MethodPost, "/api/v1/transport/policies/apply", strings.NewReader(`{"base_revision":0,"intents":[]}`))
	req1.Header.Set("Idempotency-Key", "apply-conflict-1")
	rec1 := httptest.NewRecorder()
	handleTransportPoliciesApplyExec(rec1, req1)

	req2 := httptest.NewRequest(http.MethodPost, "/api/v1/transport/policies/apply", strings.NewReader(`{"base_revision":1,"intents":[]}`))
	req2.Header.Set("Idempotency-Key", "apply-conflict-1")
	rec2 := httptest.NewRecorder()
	handleTransportPoliciesApplyExec(rec2, req2)
	if rec2.Code != http.StatusOK {
		t.Fatalf("unexpected conflict status: %d body=%s", rec2.Code, rec2.Body.String())
	}
	var resp2 TransportPolicyResponse
	if err := json.Unmarshal(rec2.Body.Bytes(), &resp2); err != nil {
		t.Fatalf("decode conflict apply response: %v", err)
	}
	if resp2.OK || resp2.Code != "IDEMPOTENCY_KEY_REUSED" {
		t.Fatalf("unexpected idempotency conflict response: %#v", resp2)
	}

	current := loadTransportPolicyState()
	if current.Revision != 1 {
		t.Fatalf("policy revision must remain 1 after conflicting replay, got %d", current.Revision)
	}
}

func TestTransportPolicyRollbackIdempotencyReplay(t *testing.T) {
	withTransportPolicyMutationTestPaths(t)

	applyReq := httptest.NewRequest(http.MethodPost, "/api/v1/transport/policies/apply", strings.NewReader(`{"base_revision":0,"intents":[]}`))
	applyRec := httptest.NewRecorder()
	handleTransportPoliciesApplyExec(applyRec, applyReq)

	req1 := httptest.NewRequest(http.MethodPost, "/api/v1/transport/policies/rollback", strings.NewReader(`{"base_revision":1}`))
	req1.Header.Set("Idempotency-Key", "rollback-replay-1")
	rec1 := httptest.NewRecorder()
	handleTransportPoliciesRollbackExec(rec1, req1)
	if rec1.Code != http.StatusOK {
		t.Fatalf("unexpected rollback status: %d body=%s", rec1.Code, rec1.Body.String())
	}
	var resp1 TransportPolicyResponse
	if err := json.Unmarshal(rec1.Body.Bytes(), &resp1); err != nil {
		t.Fatalf("decode first rollback response: %v", err)
	}
	if !resp1.OK || resp1.PolicyRevision != 2 || strings.TrimSpace(resp1.ApplyID) == "" {
		t.Fatalf("unexpected first rollback response: %#v", resp1)
	}

	req2 := httptest.NewRequest(http.MethodPost, "/api/v1/transport/policies/rollback", strings.NewReader(`{"base_revision":1}`))
	req2.Header.Set("Idempotency-Key", "rollback-replay-1")
	rec2 := httptest.NewRecorder()
	handleTransportPoliciesRollbackExec(rec2, req2)
	if rec2.Code != http.StatusOK {
		t.Fatalf("unexpected rollback replay status: %d body=%s", rec2.Code, rec2.Body.String())
	}
	var resp2 TransportPolicyResponse
	if err := json.Unmarshal(rec2.Body.Bytes(), &resp2); err != nil {
		t.Fatalf("decode replay rollback response: %v", err)
	}
	if !resp2.OK || resp2.PolicyRevision != 2 || resp2.ApplyID != resp1.ApplyID {
		t.Fatalf("unexpected rollback replay response: first=%#v second=%#v", resp1, resp2)
	}

	current := loadTransportPolicyState()
	if current.Revision != 2 {
		t.Fatalf("policy revision must remain 2 after rollback replay, got %d", current.Revision)
	}
}