package controllers

import (
	"fmt"
	"net/http"
	"strconv"
	"time"

	"github.com/gin-gonic/gin"
	"gorm.io/gorm"

	"fotbal-club/internal/models"
)

type FinancialController struct {
	db *gorm.DB
}

func NewFinancialController(db *gorm.DB) *FinancialController {
	return &FinancialController{db: db}
}

// Budget Management

// GetBudgets retrieves all budgets with optional filtering
func (fc *FinancialController) GetBudgets(c *gin.Context) {
	var budgets []models.Budget
	query := fc.db.Preload("Expenses")

	// Filter by fiscal year if provided
	if fiscalYear := c.Query("fiscal_year"); fiscalYear != "" {
		if year, err := strconv.Atoi(fiscalYear); err == nil {
			query = query.Where("fiscal_year = ?", year)
		}
	}

	// Filter by category if provided
	if category := c.Query("category"); category != "" {
		query = query.Where("category = ?", category)
	}

	// Filter by active status if provided
	if active := c.Query("active"); active != "" {
		if isActive, err := strconv.ParseBool(active); err == nil {
			query = query.Where("active = ?", isActive)
		}
	}

	if err := query.Order("category, name").Find(&budgets).Error; err != nil {
		c.JSON(http.StatusInternalServerError, gin.H{"error": "Failed to retrieve budgets"})
		return
	}

	// Calculate budget statistics for each budget
	for i := range budgets {
		budgets[i].CurrentSpend = fc.calculateBudgetSpend(budgets[i].ID)
	}

	c.JSON(http.StatusOK, budgets)
}

// GetBudget retrieves a single budget by ID
func (fc *FinancialController) GetBudget(c *gin.Context) {
	id := c.Param("id")
	var budget models.Budget

	if err := fc.db.Preload("Expenses").First(&budget, id).Error; err != nil {
		if err == gorm.ErrRecordNotFound {
			c.JSON(http.StatusNotFound, gin.H{"error": "Budget not found"})
			return
		}
		c.JSON(http.StatusInternalServerError, gin.H{"error": "Failed to retrieve budget"})
		return
	}

	// Calculate current spend
	budget.CurrentSpend = fc.calculateBudgetSpend(budget.ID)

	c.JSON(http.StatusOK, budget)
}

// CreateBudget creates a new budget
func (fc *FinancialController) CreateBudget(c *gin.Context) {
	var budget models.Budget
	if err := c.ShouldBindJSON(&budget); err != nil {
		c.JSON(http.StatusBadRequest, gin.H{"error": err.Error()})
		return
	}

	// Set default values
	if budget.FiscalYear == 0 {
		budget.FiscalYear = time.Now().Year()
	}
	if budget.StartDate.IsZero() {
		budget.StartDate = time.Date(budget.FiscalYear, 1, 1, 0, 0, 0, 0, time.UTC)
	}
	if budget.EndDate.IsZero() {
		budget.EndDate = time.Date(budget.FiscalYear, 12, 31, 23, 59, 59, 0, time.UTC)
	}

	// Get current user ID from context (set by auth middleware)
	userID, exists := c.Get("user_id")
	if exists {
		budget.CreatedBy = userID.(uint)
	}

	if err := fc.db.Create(&budget).Error; err != nil {
		c.JSON(http.StatusInternalServerError, gin.H{"error": "Failed to create budget"})
		return
	}

	c.JSON(http.StatusCreated, budget)
}

// UpdateBudget updates an existing budget
func (fc *FinancialController) UpdateBudget(c *gin.Context) {
	id := c.Param("id")
	var budget models.Budget

	if err := fc.db.First(&budget, id).Error; err != nil {
		if err == gorm.ErrRecordNotFound {
			c.JSON(http.StatusNotFound, gin.H{"error": "Budget not found"})
			return
		}
		c.JSON(http.StatusInternalServerError, gin.H{"error": "Failed to retrieve budget"})
		return
	}

	var updateData models.Budget
	if err := c.ShouldBindJSON(&updateData); err != nil {
		c.JSON(http.StatusBadRequest, gin.H{"error": err.Error()})
		return
	}

	// Update fields
	budget.Name = updateData.Name
	budget.Description = updateData.Description
	budget.Category = updateData.Category
	budget.YearlyLimit = updateData.YearlyLimit
	budget.MonthlyLimit = updateData.MonthlyLimit
	budget.FiscalYear = updateData.FiscalYear
	budget.StartDate = updateData.StartDate
	budget.EndDate = updateData.EndDate
	budget.Active = updateData.Active
	budget.AlertThreshold = updateData.AlertThreshold

	// Get current user ID from context
	userID, exists := c.Get("user_id")
	if exists {
		budget.UpdatedBy = userID.(uint)
	}

	if err := fc.db.Save(&budget).Error; err != nil {
		c.JSON(http.StatusInternalServerError, gin.H{"error": "Failed to update budget"})
		return
	}

	// Recalculate current spend
	budget.CurrentSpend = fc.calculateBudgetSpend(budget.ID)

	c.JSON(http.StatusOK, budget)
}

// DeleteBudget deletes a budget
func (fc *FinancialController) DeleteBudget(c *gin.Context) {
	id := c.Param("id")

	// Check if budget has expenses
	var expenseCount int64
	fc.db.Model(&models.Expense{}).Where("budget_id = ?", id).Count(&expenseCount)
	if expenseCount > 0 {
		c.JSON(http.StatusBadRequest, gin.H{"error": "Cannot delete budget with associated expenses"})
		return
	}

	if err := fc.db.Delete(&models.Budget{}, id).Error; err != nil {
		c.JSON(http.StatusInternalServerError, gin.H{"error": "Failed to delete budget"})
		return
	}

	c.JSON(http.StatusOK, gin.H{"message": "Budget deleted successfully"})
}

// GetBudgetCategories retrieves all unique budget categories
func (fc *FinancialController) GetBudgetCategories(c *gin.Context) {
	var categories []string
	if err := fc.db.Model(&models.Budget{}).Distinct("category").Pluck("category", &categories).Error; err != nil {
		c.JSON(http.StatusInternalServerError, gin.H{"error": "Failed to retrieve categories"})
		return
	}

	c.JSON(http.StatusOK, categories)
}

// GetBudgetOverview provides budget summary and statistics
func (fc *FinancialController) GetBudgetOverview(c *gin.Context) {
	fiscalYear := c.Query("fiscal_year")
	if fiscalYear == "" {
		fiscalYear = strconv.Itoa(time.Now().Year())
	}

	year, err := strconv.Atoi(fiscalYear)
	if err != nil {
		c.JSON(http.StatusBadRequest, gin.H{"error": "Invalid fiscal year"})
		return
	}

	var overview struct {
		TotalBudget      float64           `json:"total_budget"`
		TotalSpend       float64           `json:"total_spend"`
		RemainingBudget  float64           `json:"remaining_budget"`
		BudgetCount      int               `json:"budget_count"`
		OverBudgetCount  int               `json:"over_budget_count"`
		AlertBudgetCount int               `json:"alert_budget_count"`
		Categories       []CategorySummary `json:"categories"`
	}

	// Get all budgets for the fiscal year
	var budgets []models.Budget
	if err := fc.db.Where("fiscal_year = ? AND active = ?", year, true).Find(&budgets).Error; err != nil {
		c.JSON(http.StatusInternalServerError, gin.H{"error": "Failed to retrieve budgets"})
		return
	}

	// Calculate totals and category summaries
	categoryMap := make(map[string]*CategorySummary)
	for _, budget := range budgets {
		currentSpend := fc.calculateBudgetSpend(budget.ID)

		overview.TotalBudget += budget.YearlyLimit
		overview.TotalSpend += currentSpend

		if currentSpend > budget.YearlyLimit {
			overview.OverBudgetCount++
		} else if currentSpend > (budget.YearlyLimit * budget.AlertThreshold / 100) {
			overview.AlertBudgetCount++
		}

		// Category summary
		if _, exists := categoryMap[budget.Category]; !exists {
			categoryMap[budget.Category] = &CategorySummary{
				Category:    budget.Category,
				BudgetTotal: 0,
				SpendTotal:  0,
				BudgetCount: 0,
			}
		}
		cat := categoryMap[budget.Category]
		cat.BudgetTotal += budget.YearlyLimit
		cat.SpendTotal += currentSpend
		cat.BudgetCount++
	}

	overview.RemainingBudget = overview.TotalBudget - overview.TotalSpend
	overview.BudgetCount = len(budgets)

	// Convert category map to slice
	for _, cat := range categoryMap {
		overview.Categories = append(overview.Categories, *cat)
	}

	c.JSON(http.StatusOK, overview)
}

// Helper functions

func (fc *FinancialController) calculateBudgetSpend(budgetID uint) float64 {
	var totalSpend float64
	fc.db.Model(&models.Expense{}).Where("budget_id = ? AND status IN ?", budgetID, []string{"approved", "reimbursed"}).Select("COALESCE(SUM(total_amount), 0)").Scan(&totalSpend)
	return totalSpend
}

// CategorySummary represents budget summary by category
type CategorySummary struct {
	Category    string  `json:"category"`
	BudgetTotal float64 `json:"budget_total"`
	SpendTotal  float64 `json:"spend_total"`
	BudgetCount int     `json:"budget_count"`
}

// Sponsorship Management

// GetSponsorships retrieves all sponsorships with filtering
func (fc *FinancialController) GetSponsorships(c *gin.Context) {
	var sponsorships []models.Sponsorship
	query := fc.db.Preload("Payments").Preload("Documents")

	// Filter by status if provided
	if status := c.Query("status"); status != "" {
		query = query.Where("status = ?", status)
	}

	// Filter by contract type if provided
	if contractType := c.Query("contract_type"); contractType != "" {
		query = query.Where("contract_type = ?", contractType)
	}

	// Filter by active sponsorships
	if active := c.Query("active"); active == "true" {
		query = query.Where("status = ? AND end_date >= ?", "active", time.Now())
	}

	if err := query.Order("sponsor_name").Find(&sponsorships).Error; err != nil {
		c.JSON(http.StatusInternalServerError, gin.H{"error": "Failed to retrieve sponsorships"})
		return
	}

	c.JSON(http.StatusOK, sponsorships)
}

// GetSponsorship retrieves a single sponsorship by ID
func (fc *FinancialController) GetSponsorship(c *gin.Context) {
	id := c.Param("id")
	var sponsorship models.Sponsorship

	if err := fc.db.Preload("Payments").Preload("Documents").First(&sponsorship, id).Error; err != nil {
		if err == gorm.ErrRecordNotFound {
			c.JSON(http.StatusNotFound, gin.H{"error": "Sponsorship not found"})
			return
		}
		c.JSON(http.StatusInternalServerError, gin.H{"error": "Failed to retrieve sponsorship"})
		return
	}

	c.JSON(http.StatusOK, sponsorship)
}

// CreateSponsorship creates a new sponsorship
func (fc *FinancialController) CreateSponsorship(c *gin.Context) {
	var sponsorship models.Sponsorship
	if err := c.ShouldBindJSON(&sponsorship); err != nil {
		c.JSON(http.StatusBadRequest, gin.H{"error": err.Error()})
		return
	}

	// Set default values
	if sponsorship.Status == "" {
		sponsorship.Status = "active"
	}
	if sponsorship.Currency == "" {
		sponsorship.Currency = "CZK"
	}

	// Get current user ID from context
	userID, exists := c.Get("user_id")
	if exists {
		sponsorship.CreatedBy = userID.(uint)
	}

	if err := fc.db.Create(&sponsorship).Error; err != nil {
		c.JSON(http.StatusInternalServerError, gin.H{"error": "Failed to create sponsorship"})
		return
	}

	c.JSON(http.StatusCreated, sponsorship)
}

// UpdateSponsorship updates an existing sponsorship
func (fc *FinancialController) UpdateSponsorship(c *gin.Context) {
	id := c.Param("id")
	var sponsorship models.Sponsorship

	if err := fc.db.First(&sponsorship, id).Error; err != nil {
		if err == gorm.ErrRecordNotFound {
			c.JSON(http.StatusNotFound, gin.H{"error": "Sponsorship not found"})
			return
		}
		c.JSON(http.StatusInternalServerError, gin.H{"error": "Failed to retrieve sponsorship"})
		return
	}

	var updateData models.Sponsorship
	if err := c.ShouldBindJSON(&updateData); err != nil {
		c.JSON(http.StatusBadRequest, gin.H{"error": err.Error()})
		return
	}

	// Update fields
	sponsorship.SponsorName = updateData.SponsorName
	sponsorship.SponsorLogo = updateData.SponsorLogo
	sponsorship.ContactPerson = updateData.ContactPerson
	sponsorship.ContactEmail = updateData.ContactEmail
	sponsorship.ContactPhone = updateData.ContactPhone
	sponsorship.ContractNumber = updateData.ContractNumber
	sponsorship.ContractType = updateData.ContractType
	sponsorship.TotalValue = updateData.TotalValue
	sponsorship.PaymentSchedule = updateData.PaymentSchedule
	sponsorship.Currency = updateData.Currency
	sponsorship.StartDate = updateData.StartDate
	sponsorship.EndDate = updateData.EndDate
	sponsorship.AutoRenewal = updateData.AutoRenewal
	sponsorship.RenewalNotice = updateData.RenewalNotice
	sponsorship.Benefits = updateData.Benefits
	sponsorship.Obligations = updateData.Obligations
	sponsorship.Status = updateData.Status
	sponsorship.LastPaymentDate = updateData.LastPaymentDate
	sponsorship.NextPaymentDate = updateData.NextPaymentDate

	// Get current user ID from context
	userID, exists := c.Get("user_id")
	if exists {
		sponsorship.UpdatedBy = userID.(uint)
	}

	if err := fc.db.Save(&sponsorship).Error; err != nil {
		c.JSON(http.StatusInternalServerError, gin.H{"error": "Failed to update sponsorship"})
		return
	}

	c.JSON(http.StatusOK, sponsorship)
}

// DeleteSponsorship deletes a sponsorship
func (fc *FinancialController) DeleteSponsorship(c *gin.Context) {
	id := c.Param("id")

	if err := fc.db.Delete(&models.Sponsorship{}, id).Error; err != nil {
		c.JSON(http.StatusInternalServerError, gin.H{"error": "Failed to delete sponsorship"})
		return
	}

	c.JSON(http.StatusOK, gin.H{"message": "Sponsorship deleted successfully"})
}

// GetSponsorshipOverview provides sponsorship summary
func (fc *FinancialController) GetSponsorshipOverview(c *gin.Context) {
	var overview struct {
		TotalSponsors     int64                 `json:"total_sponsors"`
		ActiveSponsors    int64                 `json:"active_sponsors"`
		TotalValue        float64               `json:"total_value"`
		ReceivedThisYear  float64               `json:"received_this_year"`
		PendingThisYear   float64               `json:"pending_this_year"`
		ExpiringNextMonth int64                 `json:"expiring_next_month"`
		ContractTypes     []ContractTypeSummary `json:"contract_types"`
	}

	currentYear := time.Now().Year()
	nextMonth := time.Now().AddDate(0, 1, 0)

	// Count sponsors
	fc.db.Model(&models.Sponsorship{}).Count(&overview.TotalSponsors)
	fc.db.Model(&models.Sponsorship{}).Where("status = ? AND end_date >= ?", "active", time.Now()).Count(&overview.ActiveSponsors)

	// Calculate total value
	fc.db.Model(&models.Sponsorship{}).Where("status = ?", "active").Select("COALESCE(SUM(total_value), 0)").Scan(&overview.TotalValue)

	// Calculate payments this year
	fc.db.Model(&models.SponsorshipPayment{}).
		Where("EXTRACT(YEAR FROM payment_date) = ? AND status = ?", currentYear, "received").
		Select("COALESCE(SUM(amount), 0)").Scan(&overview.ReceivedThisYear)

	fc.db.Model(&models.SponsorshipPayment{}).
		Where("EXTRACT(YEAR FROM payment_date) = ? AND status = ?", currentYear, "expected").
		Select("COALESCE(SUM(amount), 0)").Scan(&overview.PendingThisYear)

	// Count expiring sponsorships
	fc.db.Model(&models.Sponsorship{}).
		Where("status = ? AND end_date <= ? AND end_date >= ?", "active", nextMonth, time.Now()).
		Count(&overview.ExpiringNextMonth)

	// Contract type summary
	var contractTypes []string
	fc.db.Model(&models.Sponsorship{}).Distinct("contract_type").Pluck("contract_type", &contractTypes)

	for _, contractType := range contractTypes {
		var count int64
		var totalValue float64
		fc.db.Model(&models.Sponsorship{}).Where("contract_type = ? AND status = ?", contractType, "active").Count(&count)
		fc.db.Model(&models.Sponsorship{}).Where("contract_type = ? AND status = ?", contractType, "active").Select("COALESCE(SUM(total_value), 0)").Scan(&totalValue)

		overview.ContractTypes = append(overview.ContractTypes, ContractTypeSummary{
			Type:       contractType,
			Count:      int(count),
			TotalValue: totalValue,
		})
	}

	c.JSON(http.StatusOK, overview)
}

type ContractTypeSummary struct {
	Type       string  `json:"type"`
	Count      int     `json:"count"`
	TotalValue float64 `json:"total_value"`
}

// Expense Management

// GetExpenses retrieves all expenses with filtering and pagination
func (fc *FinancialController) GetExpenses(c *gin.Context) {
	var expenses []models.Expense
	query := fc.db.Preload("Budget").Preload("Documents")

	// Parse pagination parameters
	page, _ := strconv.Atoi(c.DefaultQuery("page", "1"))
	limit, _ := strconv.Atoi(c.DefaultQuery("limit", "20"))
	offset := (page - 1) * limit

	// Filter by status if provided
	if status := c.Query("status"); status != "" {
		query = query.Where("status = ?", status)
	}

	// Filter by category if provided
	if category := c.Query("category"); category != "" {
		query = query.Where("category = ?", category)
	}

	// Filter by budget if provided
	if budgetID := c.Query("budget_id"); budgetID != "" {
		query = query.Where("budget_id = ?", budgetID)
	}

	// Filter by date range if provided
	if startDate := c.Query("start_date"); startDate != "" {
		if date, err := time.Parse("2006-01-02", startDate); err == nil {
			query = query.Where("expense_date >= ?", date)
		}
	}
	if endDate := c.Query("end_date"); endDate != "" {
		if date, err := time.Parse("2006-01-02", endDate); err == nil {
			query = query.Where("expense_date <= ?", date)
		}
	}

	// Get total count for pagination
	var total int64
	countQuery := query
	if err := countQuery.Model(&models.Expense{}).Count(&total).Error; err != nil {
		c.JSON(http.StatusInternalServerError, gin.H{"error": "Failed to count expenses"})
		return
	}

	// Apply pagination and ordering
	if err := query.Order("expense_date DESC, created_at DESC").Limit(limit).Offset(offset).Find(&expenses).Error; err != nil {
		c.JSON(http.StatusInternalServerError, gin.H{"error": "Failed to retrieve expenses"})
		return
	}

	// Return paginated response
	c.JSON(http.StatusOK, gin.H{
		"expenses": expenses,
		"total":    total,
		"page":     page,
		"limit":    limit,
		"pages":    (total + int64(limit) - 1) / int64(limit),
	})
}

// GetExpense retrieves a single expense by ID
func (fc *FinancialController) GetExpense(c *gin.Context) {
	id := c.Param("id")
	var expense models.Expense

	if err := fc.db.Preload("Budget").Preload("Documents").First(&expense, id).Error; err != nil {
		if err == gorm.ErrRecordNotFound {
			c.JSON(http.StatusNotFound, gin.H{"error": "Expense not found"})
			return
		}
		c.JSON(http.StatusInternalServerError, gin.H{"error": "Failed to retrieve expense"})
		return
	}

	c.JSON(http.StatusOK, expense)
}

// CreateExpense creates a new expense
func (fc *FinancialController) CreateExpense(c *gin.Context) {
	var expense models.Expense
	if err := c.ShouldBindJSON(&expense); err != nil {
		c.JSON(http.StatusBadRequest, gin.H{"error": err.Error()})
		return
	}

	// Set default values
	if expense.Currency == "" {
		expense.Currency = "CZK"
	}
	if expense.VATRate == 0 {
		expense.VATRate = 21
	}
	if expense.Status == "" {
		expense.Status = "pending"
	}
	if expense.ExpenseDate.IsZero() {
		expense.ExpenseDate = time.Now()
	}

	// Calculate VAT and total amounts if not provided
	if expense.VATAmount == 0 && expense.Amount > 0 {
		expense.VATAmount = expense.Amount * expense.VATRate / 100
	}
	if expense.TotalAmount == 0 {
		expense.TotalAmount = expense.Amount + expense.VATAmount
	}

	// Get current user ID from context
	userID, exists := c.Get("user_id")
	if exists {
		expense.CreatedBy = userID.(uint)
	}

	// Auto-approve if amount is below threshold and approval is not required
	// This would need to check FinancialSettings, but for now auto-approve amounts <= 1000
	if expense.Amount <= 1000 {
		expense.Status = "approved"
		now := time.Now()
		expense.ApprovedAt = &now
		if userID != nil {
			expense.ApprovedBy = userID.(uint)
		}
	}

	if err := fc.db.Create(&expense).Error; err != nil {
		c.JSON(http.StatusInternalServerError, gin.H{"error": "Failed to create expense"})
		return
	}

	// Reload with associations
	if err := fc.db.Preload("Budget").Preload("Documents").First(&expense, expense.ID).Error; err != nil {
		c.JSON(http.StatusInternalServerError, gin.H{"error": "Failed to retrieve created expense"})
		return
	}

	c.JSON(http.StatusCreated, expense)
}

// UpdateExpense updates an existing expense
func (fc *FinancialController) UpdateExpense(c *gin.Context) {
	id := c.Param("id")
	var expense models.Expense

	if err := fc.db.First(&expense, id).Error; err != nil {
		if err == gorm.ErrRecordNotFound {
			c.JSON(http.StatusNotFound, gin.H{"error": "Expense not found"})
			return
		}
		c.JSON(http.StatusInternalServerError, gin.H{"error": "Failed to retrieve expense"})
		return
	}

	var updateData models.Expense
	if err := c.ShouldBindJSON(&updateData); err != nil {
		c.JSON(http.StatusBadRequest, gin.H{"error": err.Error()})
		return
	}

	// Don't allow updating approved/reimbursed expenses unless admin
	if expense.Status == "approved" || expense.Status == "reimbursed" {
		// Check if user is admin (simplified check)
		userRole, _ := c.Get("user_role")
		if userRole != "admin" {
			c.JSON(http.StatusForbidden, gin.H{"error": "Cannot update approved expense"})
			return
		}
	}

	// Update fields
	expense.Title = updateData.Title
	expense.Description = updateData.Description
	expense.Category = updateData.Category
	expense.Subcategory = updateData.Subcategory
	expense.Amount = updateData.Amount
	expense.Currency = updateData.Currency
	expense.VATRate = updateData.VATRate
	expense.VATAmount = updateData.VATAmount
	expense.TotalAmount = updateData.TotalAmount
	expense.ExpenseDate = updateData.ExpenseDate
	expense.PaymentMethod = updateData.PaymentMethod
	expense.HasReceipt = updateData.HasReceipt
	expense.ReceiptData = updateData.ReceiptData
	expense.ReceiptImage = updateData.ReceiptImage
	expense.BudgetID = updateData.BudgetID
	expense.TeamID = updateData.TeamID
	expense.ProjectID = updateData.ProjectID

	// Get current user ID from context
	userID, exists := c.Get("user_id")
	if exists {
		expense.UpdatedBy = userID.(uint)
	}

	if err := fc.db.Save(&expense).Error; err != nil {
		c.JSON(http.StatusInternalServerError, gin.H{"error": "Failed to update expense"})
		return
	}

	// Reload with associations
	if err := fc.db.Preload("Budget").Preload("Documents").First(&expense, expense.ID).Error; err != nil {
		c.JSON(http.StatusInternalServerError, gin.H{"error": "Failed to retrieve updated expense"})
		return
	}

	c.JSON(http.StatusOK, expense)
}

// DeleteExpense deletes an expense
func (fc *FinancialController) DeleteExpense(c *gin.Context) {
	id := c.Param("id")
	var expense models.Expense

	if err := fc.db.First(&expense, id).Error; err != nil {
		if err == gorm.ErrRecordNotFound {
			c.JSON(http.StatusNotFound, gin.H{"error": "Expense not found"})
			return
		}
		c.JSON(http.StatusInternalServerError, gin.H{"error": "Failed to retrieve expense"})
		return
	}

	// Don't allow deleting approved/reimbursed expenses unless admin
	if expense.Status == "approved" || expense.Status == "reimbursed" {
		userRole, _ := c.Get("user_role")
		if userRole != "admin" {
			c.JSON(http.StatusForbidden, gin.H{"error": "Cannot delete approved expense"})
			return
		}
	}

	if err := fc.db.Delete(&expense).Error; err != nil {
		c.JSON(http.StatusInternalServerError, gin.H{"error": "Failed to delete expense"})
		return
	}

	c.JSON(http.StatusOK, gin.H{"message": "Expense deleted successfully"})
}

// ApproveExpense approves an expense
func (fc *FinancialController) ApproveExpense(c *gin.Context) {
	id := c.Param("id")
	var expense models.Expense

	if err := fc.db.First(&expense, id).Error; err != nil {
		if err == gorm.ErrRecordNotFound {
			c.JSON(http.StatusNotFound, gin.H{"error": "Expense not found"})
			return
		}
		c.JSON(http.StatusInternalServerError, gin.H{"error": "Failed to retrieve expense"})
		return
	}

	if expense.Status != "pending" {
		c.JSON(http.StatusBadRequest, gin.H{"error": "Expense is not pending"})
		return
	}

	// Get current user ID from context
	userID, exists := c.Get("user_id")
	if !exists {
		c.JSON(http.StatusUnauthorized, gin.H{"error": "User not authenticated"})
		return
	}

	now := time.Now()
	expense.Status = "approved"
	expense.ApprovedAt = &now
	expense.ApprovedBy = userID.(uint)
	expense.UpdatedBy = userID.(uint)

	if err := fc.db.Save(&expense).Error; err != nil {
		c.JSON(http.StatusInternalServerError, gin.H{"error": "Failed to approve expense"})
		return
	}

	c.JSON(http.StatusOK, expense)
}

// RejectExpense rejects an expense
func (fc *FinancialController) RejectExpense(c *gin.Context) {
	id := c.Param("id")

	var request struct {
		RejectionReason string `json:"rejection_reason" binding:"required"`
	}

	if err := c.ShouldBindJSON(&request); err != nil {
		c.JSON(http.StatusBadRequest, gin.H{"error": err.Error()})
		return
	}

	var expense models.Expense
	if err := fc.db.First(&expense, id).Error; err != nil {
		if err == gorm.ErrRecordNotFound {
			c.JSON(http.StatusNotFound, gin.H{"error": "Expense not found"})
			return
		}
		c.JSON(http.StatusInternalServerError, gin.H{"error": "Failed to retrieve expense"})
		return
	}

	if expense.Status != "pending" {
		c.JSON(http.StatusBadRequest, gin.H{"error": "Expense is not pending"})
		return
	}

	// Get current user ID from context
	userID, exists := c.Get("user_id")
	if !exists {
		c.JSON(http.StatusUnauthorized, gin.H{"error": "User not authenticated"})
		return
	}

	expense.Status = "rejected"
	expense.RejectionReason = request.RejectionReason
	expense.UpdatedBy = userID.(uint)

	if err := fc.db.Save(&expense).Error; err != nil {
		c.JSON(http.StatusInternalServerError, gin.H{"error": "Failed to reject expense"})
		return
	}

	c.JSON(http.StatusOK, expense)
}

// UploadReceipt handles receipt upload for expenses
func (fc *FinancialController) UploadReceipt(c *gin.Context) {
	// This would handle file upload and OCR processing
	// For now, return a placeholder response
	c.JSON(http.StatusNotImplemented, gin.H{"error": "Receipt upload not implemented yet"})
}

// GetExpenseCategories retrieves all unique expense categories
func (fc *FinancialController) GetExpenseCategories(c *gin.Context) {
	var categories []string
	if err := fc.db.Model(&models.Expense{}).Distinct("category").Pluck("category", &categories).Error; err != nil {
		c.JSON(http.StatusInternalServerError, gin.H{"error": "Failed to retrieve categories"})
		return
	}

	c.JSON(http.StatusOK, categories)
}

// GetExpenseOverview provides expense summary and statistics
func (fc *FinancialController) GetExpenseOverview(c *gin.Context) {
	var overview struct {
		TotalExpenses      float64           `json:"total_expenses"`
		PendingExpenses    float64           `json:"pending_expenses"`
		ApprovedExpenses   float64           `json:"approved_expenses"`
		RejectedExpenses   float64           `json:"rejected_expenses"`
		ReimbursedExpenses float64           `json:"reimbursed_expenses"`
		ExpenseCount       int               `json:"expense_count"`
		ThisMonthExpenses  float64           `json:"this_month_expenses"`
		Categories         []CategorySummary `json:"categories"`
	}

	// Get current month boundaries
	now := time.Now()
	startOfMonth := time.Date(now.Year(), now.Month(), 1, 0, 0, 0, 0, now.Location())

	// Calculate totals by status
	fc.db.Model(&models.Expense{}).Select("COALESCE(SUM(total_amount), 0)").Where("status = ?", "pending").Scan(&overview.PendingExpenses)
	fc.db.Model(&models.Expense{}).Select("COALESCE(SUM(total_amount), 0)").Where("status = ?", "approved").Scan(&overview.ApprovedExpenses)
	fc.db.Model(&models.Expense{}).Select("COALESCE(SUM(total_amount), 0)").Where("status = ?", "rejected").Scan(&overview.RejectedExpenses)
	fc.db.Model(&models.Expense{}).Select("COALESCE(SUM(total_amount), 0)").Where("status = ?", "reimbursed").Scan(&overview.ReimbursedExpenses)

	// Total expenses
	overview.TotalExpenses = overview.PendingExpenses + overview.ApprovedExpenses + overview.ReimbursedExpenses

	// Count all expenses
	var expenseCount int64
	fc.db.Model(&models.Expense{}).Count(&expenseCount)
	overview.ExpenseCount = int(expenseCount)

	// This month expenses
	fc.db.Model(&models.Expense{}).Where("expense_date >= ?", startOfMonth).Select("COALESCE(SUM(total_amount), 0)").Scan(&overview.ThisMonthExpenses)

	// Category summary
	var categories []string
	fc.db.Model(&models.Expense{}).Distinct("category").Pluck("category", &categories)

	for _, category := range categories {
		var count int64
		var total float64
		fc.db.Model(&models.Expense{}).Where("category = ?", category).Count(&count)
		fc.db.Model(&models.Expense{}).Where("category = ?", category).Select("COALESCE(SUM(total_amount), 0)").Scan(&total)

		overview.Categories = append(overview.Categories, CategorySummary{
			Category:    category,
			BudgetTotal: total, // Using BudgetTotal field for expense total
			SpendTotal:  total, // Same for expenses
			BudgetCount: int(count),
		})
	}

	c.JSON(http.StatusOK, overview)
}

// Financial Dashboard and Settings

// GetFinancialDashboard provides comprehensive financial overview
func (fc *FinancialController) GetFinancialDashboard(c *gin.Context) {
	var dashboard struct {
		// Budget summary
		BudgetSummary struct {
			TotalBudget     float64 `json:"total_budget"`
			TotalSpend      float64 `json:"total_spend"`
			RemainingBudget float64 `json:"remaining_budget"`
			BudgetCount     int     `json:"budget_count"`
			OverBudgetCount int     `json:"over_budget_count"`
		} `json:"budget_summary"`

		// Expense summary
		ExpenseSummary struct {
			TotalExpenses     float64 `json:"total_expenses"`
			PendingExpenses   float64 `json:"pending_expenses"`
			ApprovedExpenses  float64 `json:"approved_expenses"`
			ThisMonthExpenses float64 `json:"this_month_expenses"`
			ExpenseCount      int     `json:"expense_count"`
			PendingCount      int     `json:"pending_count"`
		} `json:"expense_summary"`

		// Sponsorship summary
		SponsorshipSummary struct {
			TotalSponsors    int64   `json:"total_sponsors"`
			ActiveSponsors   int64   `json:"active_sponsors"`
			TotalValue       float64 `json:"total_value"`
			ReceivedThisYear float64 `json:"received_this_year"`
		} `json:"sponsorship_summary"`

		// Recent activities
		RecentExpenses     []models.Expense     `json:"recent_expenses"`
		RecentSponsorships []models.Sponsorship `json:"recent_sponsorships"`
	}

	// Get budget summary
	var budgets []models.Budget
	if err := fc.db.Where("active = ?", true).Find(&budgets).Error; err == nil {
		for _, budget := range budgets {
			dashboard.BudgetSummary.TotalBudget += budget.YearlyLimit
			currentSpend := fc.calculateBudgetSpend(budget.ID)
			dashboard.BudgetSummary.TotalSpend += currentSpend
			if currentSpend > budget.YearlyLimit {
				dashboard.BudgetSummary.OverBudgetCount++
			}
		}
		dashboard.BudgetSummary.BudgetCount = len(budgets)
		dashboard.BudgetSummary.RemainingBudget = dashboard.BudgetSummary.TotalBudget - dashboard.BudgetSummary.TotalSpend
	}

	// Get expense summary
	fc.db.Model(&models.Expense{}).Select("COALESCE(SUM(total_amount), 0)").Scan(&dashboard.ExpenseSummary.TotalExpenses)
	fc.db.Model(&models.Expense{}).Select("COALESCE(SUM(total_amount), 0)").Where("status = ?", "pending").Scan(&dashboard.ExpenseSummary.PendingExpenses)
	fc.db.Model(&models.Expense{}).Select("COALESCE(SUM(total_amount), 0)").Where("status = ?", "approved").Scan(&dashboard.ExpenseSummary.ApprovedExpenses)

	var expenseCount, pendingCount int64
	fc.db.Model(&models.Expense{}).Count(&expenseCount)
	fc.db.Model(&models.Expense{}).Where("status = ?", "pending").Count(&pendingCount)
	dashboard.ExpenseSummary.ExpenseCount = int(expenseCount)
	dashboard.ExpenseSummary.PendingCount = int(pendingCount)

	// This month expenses
	now := time.Now()
	startOfMonth := time.Date(now.Year(), now.Month(), 1, 0, 0, 0, 0, now.Location())
	fc.db.Model(&models.Expense{}).Where("expense_date >= ?", startOfMonth).Select("COALESCE(SUM(total_amount), 0)").Scan(&dashboard.ExpenseSummary.ThisMonthExpenses)

	// Get sponsorship summary
	fc.db.Model(&models.Sponsorship{}).Count(&dashboard.SponsorshipSummary.TotalSponsors)
	fc.db.Model(&models.Sponsorship{}).Where("status = ? AND end_date >= ?", "active", time.Now()).Count(&dashboard.SponsorshipSummary.ActiveSponsors)
	fc.db.Model(&models.Sponsorship{}).Where("status = ?", "active").Select("COALESCE(SUM(total_value), 0)").Scan(&dashboard.SponsorshipSummary.TotalValue)

	currentYear := now.Year()
	fc.db.Model(&models.SponsorshipPayment{}).
		Where("EXTRACT(YEAR FROM payment_date) = ? AND status = ?", currentYear, "received").
		Select("COALESCE(SUM(amount), 0)").Scan(&dashboard.SponsorshipSummary.ReceivedThisYear)

	// Get recent expenses (last 10)
	fc.db.Preload("Budget").Order("created_at DESC").Limit(10).Find(&dashboard.RecentExpenses)

	// Get recent sponsorships (last 5)
	fc.db.Order("created_at DESC").Limit(5).Find(&dashboard.RecentSponsorships)

	c.JSON(http.StatusOK, dashboard)
}

// Financial Reports Management

// GetFinancialReports retrieves all financial reports
func (fc *FinancialController) GetFinancialReports(c *gin.Context) {
	var reports []models.FinancialReport
	if err := fc.db.Order("created_at DESC").Find(&reports).Error; err != nil {
		c.JSON(http.StatusInternalServerError, gin.H{"error": "Failed to retrieve reports"})
		return
	}

	c.JSON(http.StatusOK, reports)
}

// GenerateFinancialReport generates a new financial report
func (fc *FinancialController) GenerateFinancialReport(c *gin.Context) {
	var request struct {
		Name   string `json:"name" binding:"required"`
		Type   string `json:"type" binding:"required"`
		Period string `json:"period" binding:"required"`
	}

	if err := c.ShouldBindJSON(&request); err != nil {
		c.JSON(http.StatusBadRequest, gin.H{"error": err.Error()})
		return
	}

	// Get current user ID from context
	userID, exists := c.Get("user_id")
	if !exists {
		c.JSON(http.StatusUnauthorized, gin.H{"error": "User not authenticated"})
		return
	}

	report := models.FinancialReport{
		Name:        request.Name,
		Type:        request.Type,
		Period:      request.Period,
		GeneratedAt: time.Now(),
		CreatedBy:   userID.(uint),
	}

	// Generate report data based on type
	reportData, summary := fc.generateReportData(request.Type, request.Period)
	report.ReportData = reportData
	report.Summary = summary

	if err := fc.db.Create(&report).Error; err != nil {
		c.JSON(http.StatusInternalServerError, gin.H{"error": "Failed to create report"})
		return
	}

	c.JSON(http.StatusCreated, report)
}

// GetFinancialReport retrieves a single financial report
func (fc *FinancialController) GetFinancialReport(c *gin.Context) {
	id := c.Param("id")
	var report models.FinancialReport

	if err := fc.db.First(&report, id).Error; err != nil {
		if err == gorm.ErrRecordNotFound {
			c.JSON(http.StatusNotFound, gin.H{"error": "Report not found"})
			return
		}
		c.JSON(http.StatusInternalServerError, gin.H{"error": "Failed to retrieve report"})
		return
	}

	c.JSON(http.StatusOK, report)
}

// DeleteFinancialReport deletes a financial report
func (fc *FinancialController) DeleteFinancialReport(c *gin.Context) {
	id := c.Param("id")

	if err := fc.db.Delete(&models.FinancialReport{}, id).Error; err != nil {
		c.JSON(http.StatusInternalServerError, gin.H{"error": "Failed to delete report"})
		return
	}

	c.JSON(http.StatusOK, gin.H{"message": "Report deleted successfully"})
}

// Financial Settings Management

// GetFinancialSettings retrieves financial settings
func (fc *FinancialController) GetFinancialSettings(c *gin.Context) {
	var settings models.FinancialSettings

	// Get or create settings (singleton pattern)
	if err := fc.db.First(&settings).Error; err != nil {
		if err == gorm.ErrRecordNotFound {
			// Create default settings
			settings = models.FinancialSettings{
				DefaultCurrency:         "CZK",
				DefaultVATRate:          21,
				FiscalYearStart:         "01-01",
				ExpenseApprovalRequired: true,
				MaxExpenseAutoApprove:   1000,
				BudgetAlertEnabled:      true,
				BudgetAlertThreshold:    80,
				SponsorshipAlertEnabled: true,
				OCRServiceEnabled:       true,
				OCRProvider:             "tesseract",
			}
			fc.db.Create(&settings)
		} else {
			c.JSON(http.StatusInternalServerError, gin.H{"error": "Failed to retrieve settings"})
			return
		}
	}

	c.JSON(http.StatusOK, settings)
}

// UpdateFinancialSettings updates financial settings
func (fc *FinancialController) UpdateFinancialSettings(c *gin.Context) {
	var settings models.FinancialSettings

	// Get existing settings
	if err := fc.db.First(&settings).Error; err != nil {
		if err == gorm.ErrRecordNotFound {
			// Create if not exists
			if err := c.ShouldBindJSON(&settings); err != nil {
				c.JSON(http.StatusBadRequest, gin.H{"error": err.Error()})
				return
			}

			// Get current user ID from context
			userID, exists := c.Get("user_id")
			if exists {
				settings.UpdatedBy = userID.(uint)
			}

			if err := fc.db.Create(&settings).Error; err != nil {
				c.JSON(http.StatusInternalServerError, gin.H{"error": "Failed to create settings"})
				return
			}
		} else {
			c.JSON(http.StatusInternalServerError, gin.H{"error": "Failed to retrieve settings"})
			return
		}
	} else {
		// Update existing
		var updateData models.FinancialSettings
		if err := c.ShouldBindJSON(&updateData); err != nil {
			c.JSON(http.StatusBadRequest, gin.H{"error": err.Error()})
			return
		}

		// Update fields
		settings.DefaultCurrency = updateData.DefaultCurrency
		settings.DefaultVATRate = updateData.DefaultVATRate
		settings.FiscalYearStart = updateData.FiscalYearStart
		settings.ExpenseApprovalRequired = updateData.ExpenseApprovalRequired
		settings.MaxExpenseAutoApprove = updateData.MaxExpenseAutoApprove
		settings.BudgetAlertEnabled = updateData.BudgetAlertEnabled
		settings.BudgetAlertThreshold = updateData.BudgetAlertThreshold
		settings.SponsorshipAlertEnabled = updateData.SponsorshipAlertEnabled
		settings.OCRServiceEnabled = updateData.OCRServiceEnabled
		settings.OCRProvider = updateData.OCRProvider

		// Get current user ID from context
		userID, exists := c.Get("user_id")
		if exists {
			settings.UpdatedBy = userID.(uint)
		}

		if err := fc.db.Save(&settings).Error; err != nil {
			c.JSON(http.StatusInternalServerError, gin.H{"error": "Failed to update settings"})
			return
		}
	}

	c.JSON(http.StatusOK, settings)
}

// Helper function to generate report data
func (fc *FinancialController) generateReportData(reportType, period string) (string, string) {
	// This is a placeholder implementation
	// In a real implementation, you would generate comprehensive JSON data based on the report type and period
	reportData := `{
		"expenses": {"total": 0, "by_category": {}, "by_month": {}},
		"budgets": {"total": 0, "utilization": {}},
		"sponsorships": {"total": 0, "by_status": {}},
		"generated_at": "` + time.Now().Format(time.RFC3339) + `"
	}`

	summary := fmt.Sprintf("Financial report for %s - %s", period, reportType)

	return reportData, summary
}