package handlers

import (
	"bytes"
	"encoding/json"
	"net/http"
	"net/http/httptest"
	"testing"

	"github.com/go-chi/chi/v5"
	"github.com/stretchr/testify/assert"
	"github.com/stretchr/testify/require"
)

// MockDB is a simple mock for testing
type MockDB struct{}

func TestHealthHandler(t *testing.T) {
	handler := NewHealthHandler()
	req := httptest.NewRequest(http.MethodGet, "/health", nil)
	rr := httptest.NewRecorder()

	handler.ServeHTTP(rr, req)

	assert.Equal(t, http.StatusOK, rr.Code)
	
	var response map[string]interface{}
	err := json.Unmarshal(rr.Body.Bytes(), &response)
	require.NoError(t, err)
	assert.Equal(t, true, response["ok"])
}

func TestWriteJSON(t *testing.T) {
	rr := httptest.NewRecorder()
	data := map[string]string{"key": "value"}
	
	writeJSON(rr, http.StatusOK, data)
	
	assert.Equal(t, http.StatusOK, rr.Code)
	assert.Equal(t, "application/json", rr.Header().Get("Content-Type"))
	
	var response map[string]string
	err := json.Unmarshal(rr.Body.Bytes(), &response)
	require.NoError(t, err)
	assert.Equal(t, "value", response["key"])
}

func TestWriteError(t *testing.T) {
	rr := httptest.NewRecorder()
	writeError(rr, http.StatusBadRequest, "test error")
	
	assert.Equal(t, http.StatusBadRequest, rr.Code)
	
	var response map[string]interface{}
	err := json.Unmarshal(rr.Body.Bytes(), &response)
	require.NoError(t, err)
	assert.Equal(t, "test error", response["error"])
}

func TestCRMHandler_CreateCustomer_RequestParsing(t *testing.T) {
	// Test request parsing only — DB tests are in crm_test.go
	payload := map[string]interface{}{
		"name":    "Test Customer",
		"email":   "test@example.com",
		"phone":   "+46701234567",
		"company": "Test AB",
		"status":  "lead",
	}

	body, _ := json.Marshal(payload)
	req := httptest.NewRequest(http.MethodPost, "/api/v1/crm/customers", bytes.NewReader(body))
	req.Header.Set("Content-Type", "application/json")

	assert.NotNil(t, req)
	assert.Equal(t, "application/json", req.Header.Get("Content-Type"))
}

func TestQuoteHandler_CreateQuote(t *testing.T) {
	payload := map[string]interface{}{
		"customer_id": "test-customer-id",
		"title":       "Test Quote",
		"description": "Test description",
		"valid_until": "2026-12-31",
		"items": []map[string]interface{}{
			{
				"description": "Item 1",
				"quantity":    2,
				"unit_price":  100.00,
				"tax_rate":    25.0,
			},
		},
	}
	
	body, _ := json.Marshal(payload)
	req := httptest.NewRequest(http.MethodPost, "/api/v1/sales/quotes", bytes.NewReader(body))
	req.Header.Set("Content-Type", "application/json")
	
	assert.NotNil(t, req)
	
	var parsed map[string]interface{}
	err := json.Unmarshal(body, &parsed)
	require.NoError(t, err)
	assert.Equal(t, "Test Quote", parsed["title"])
	
	items := parsed["items"].([]interface{})
	assert.Len(t, items, 1)
}

func TestSubscriptionHandler_CreateSubscription(t *testing.T) {
	payload := map[string]interface{}{
		"customer_id": "test-customer",
		"plan_id":     "test-plan",
		"start_date":  "2026-07-12",
	}
	
	body, _ := json.Marshal(payload)
	req := httptest.NewRequest(http.MethodPost, "/api/v1/subscriptions", bytes.NewReader(body))
	req.Header.Set("Content-Type", "application/json")
	
	assert.NotNil(t, req)
}

func TestBankHandler_MatchTransaction(t *testing.T) {
	payload := map[string]interface{}{
		"match_type": "invoice",
		"match_id":   "inv-123",
	}
	
	body, _ := json.Marshal(payload)
	req := httptest.NewRequest(http.MethodPost, "/api/v1/bank/transactions/tx-123/match", bytes.NewReader(body))
	req.Header.Set("Content-Type", "application/json")
	
	assert.NotNil(t, req)
}

func TestProjectHandler_AddTime(t *testing.T) {
	payload := map[string]interface{}{
		"employee_id": "emp-1",
		"date":        "2026-07-12",
		"hours":       8.0,
		"description": "Development work",
		"billable":    true,
		"hourly_rate": 150.00,
	}
	
	body, _ := json.Marshal(payload)
	req := httptest.NewRequest(http.MethodPost, "/api/v1/projects/proj-1/time", bytes.NewReader(body))
	req.Header.Set("Content-Type", "application/json")
	
	assert.NotNil(t, req)
}

func TestReceiptHandler_UploadReceipt(t *testing.T) {
	payload := map[string]interface{}{
		"employee_id": "emp-1",
		"image_url":   "https://example.com/receipt.jpg",
	}
	
	body, _ := json.Marshal(payload)
	req := httptest.NewRequest(http.MethodPost, "/api/v1/receipts", bytes.NewReader(body))
	req.Header.Set("Content-Type", "application/json")
	
	assert.NotNil(t, req)
}

func TestPayrollHandler_ProcessPayroll(t *testing.T) {
	// Test that the endpoint exists and accepts POST
	router := chi.NewRouter()
	router.Post("/api/v1/payroll/runs/{id}/process", func(w http.ResponseWriter, r *http.Request) {
		writeJSON(w, http.StatusOK, map[string]interface{}{"message": "Payroll processed"})
	})
	
	req := httptest.NewRequest(http.MethodPost, "/api/v1/payroll/runs/run-1/process", nil)
	rr := httptest.NewRecorder()
	
	router.ServeHTTP(rr, req)
	
	assert.Equal(t, http.StatusOK, rr.Code)
	
	var response map[string]interface{}
	err := json.Unmarshal(rr.Body.Bytes(), &response)
	require.NoError(t, err)
	assert.Equal(t, "Payroll processed", response["message"])
}

func TestInventoryHandler_AdjustStock(t *testing.T) {
	payload := map[string]interface{}{
		"product_id":   "prod-1",
		"warehouse_id": "wh-1",
		"quantity":     100.0,
		"reason":       "Initial stock",
	}
	
	body, _ := json.Marshal(payload)
	req := httptest.NewRequest(http.MethodPost, "/api/v1/inventory/adjust", bytes.NewReader(body))
	req.Header.Set("Content-Type", "application/json")
	
	assert.NotNil(t, req)
}

// Benchmark tests
func BenchmarkWriteJSON(b *testing.B) {
	data := map[string]interface{}{
		"id":      "test-id",
		"name":    "Test",
		"amount":  1000.00,
		"items":   []string{"a", "b", "c"},
	}
	
	for i := 0; i < b.N; i++ {
		rr := httptest.NewRecorder()
		writeJSON(rr, http.StatusOK, data)
	}
}

func BenchmarkQuoteCalculation(b *testing.B) {
	items := []struct {
		Quantity  float64
		UnitPrice float64
		TaxRate   float64
		Discount  float64
	}{
		{2, 100, 25, 0},
		{5, 50, 25, 10},
		{1, 200, 25, 0},
	}
	
	for i := 0; i < b.N; i++ {
		var total float64
		for _, item := range items {
			itemTotal := item.Quantity * item.UnitPrice * (1 - item.Discount/100)
			itemTax := itemTotal * (item.TaxRate / 100)
			total += itemTotal + itemTax
		}
		_ = total
	}
}