package handlers

import (
	"net/http"
	"time"
)

// AccountingHandler hanterar dubbel bokföring — egen ledger + Visma
type AccountingHandler struct{}

func NewAccountingHandler() *AccountingHandler {
	return &AccountingHandler{}
}

// LedgerEntry representerar en bokföringspost
type LedgerEntry struct {
	ID          string    `json:"id"`
	Date        string    `json:"date"`
	VoucherNo   string    `json:"voucher_no"`
	Description string    `json:"description"`
	Account     string    `json:"account"`
	AccountName string    `json:"account_name"`
	Debit       float64   `json:"debit"`
	Credit      float64   `json:"credit"`
	Balance     float64   `json:"balance"`
	Source      string    `json:"source"`
	Synced      bool      `json:"synced"`
	VismaID     *string   `json:"visma_id,omitempty"`
	CreatedAt   time.Time `json:"created_at"`
}

// AccountBalance representerar kontosaldo
type AccountBalance struct {
	Code        string  `json:"code"`
	Name        string  `json:"name"`
	Type        string  `json:"type"`
	Balance     float64 `json:"balance"`
	LastUpdated string  `json:"last_updated"`
}

// VismaConnection representerar Visma-koppling
type VismaConnection struct {
	Connected     bool      `json:"connected"`
	Company       string    `json:"company"`
	OrgNumber     string    `json:"org_number"`
	LastSync      time.Time `json:"last_sync"`
	SyncStatus    string    `json:"sync_status"`
	PendingSync   int       `json:"pending_sync"`
}

// GetLedger returnerar egen ledger
type GetLedger struct{}

func (h *AccountingHandler) GetLedger(w http.ResponseWriter, r *http.Request) {
	entries := []LedgerEntry{
		{
			ID:          "le-001",
			Date:        "2026-08-01",
			VoucherNo:   "V-2026-081",
			Description: "Faktura #1001 — Kundtjänst AB",
			Account:     "1510",
			AccountName: "Kundfordringar",
			Debit:       25000,
			Credit:      0,
			Balance:     25000,
			Source:      "internal",
			Synced:      true,
			VismaID:     strPtr("visma-88123"),
			CreatedAt:   time.Now().Add(-96 * time.Hour),
		},
		{
			ID:          "le-002",
			Date:        "2026-08-01",
			VoucherNo:   "V-2026-081",
			Description: "Faktura #1001 — Kundtjänst AB",
			Account:     "3010",
			AccountName: "Försäljning tjänster",
			Debit:       0,
			Credit:      25000,
			Balance:     -25000,
			Source:      "internal",
			Synced:      true,
			VismaID:     strPtr("visma-88124"),
			CreatedAt:   time.Now().Add(-96 * time.Hour),
		},
		{
			ID:          "le-003",
			Date:        "2026-08-02",
			VoucherNo:   "V-2026-082",
			Description: "Leverantörsfaktura #L-442 — AWS",
			Account:     "2440",
			AccountName: "Leverantörsskulder",
			Debit:       0,
			Credit:      8500,
			Balance:     -8500,
			Source:      "visma",
			Synced:      true,
			VismaID:     strPtr("visma-88125"),
			CreatedAt:   time.Now().Add(-72 * time.Hour),
		},
		{
			ID:          "le-004",
			Date:        "2026-08-02",
			VoucherNo:   "V-2026-082",
			Description: "Leverantörsfaktura #L-442 — AWS",
			Account:     "6540",
			AccountName: "IT-kostnader",
			Debit:       8500,
			Credit:      0,
			Balance:     8500,
			Source:      "visma",
			Synced:      true,
			VismaID:     strPtr("visma-88126"),
			CreatedAt:   time.Now().Add(-72 * time.Hour),
		},
		{
			ID:          "le-005",
			Date:        "2026-08-03",
			VoucherNo:   "V-2026-083",
			Description: "Lön — Erik Svensson",
			Account:     "7210",
			AccountName: "Löner",
			Debit:       45000,
			Credit:      0,
			Balance:     45000,
			Source:      "internal",
			Synced:      false,
			VismaID:     nil,
			CreatedAt:   time.Now().Add(-48 * time.Hour),
		},
		{
			ID:          "le-006",
			Date:        "2026-08-03",
			VoucherNo:   "V-2026-083",
			Description: "Lön — Erik Svensson",
			Account:     "1930",
			AccountName: "Företagskonto/checkkonto/räkning",
			Debit:       0,
			Credit:      45000,
			Balance:     -45000,
			Source:      "internal",
			Synced:      false,
			VismaID:     nil,
			CreatedAt:   time.Now().Add(-48 * time.Hour),
		},
		{
			ID:          "le-007",
			Date:        "2026-08-04",
			VoucherNo:   "V-2026-084",
			Description: "Zoomer-utbetalning — Anna Lindqvist",
			Account:     "7690",
			AccountName: "Övriga personalkostnader",
			Debit:       5000,
			Credit:      0,
			Balance:     5000,
			Source:      "quixzoom",
			Synced:      false,
			VismaID:     nil,
			CreatedAt:   time.Now().Add(-24 * time.Hour),
		},
		{
			ID:          "le-008",
			Date:        "2026-08-04",
			VoucherNo:   "V-2026-084",
			Description: "Zoomer-utbetalning — Anna Lindqvist",
			Account:     "1930",
			AccountName: "Företagskonto/checkkonto/räkning",
			Debit:       0,
			Credit:      5000,
			Balance:     -5000,
			Source:      "quixzoom",
			Synced:      false,
			VismaID:     nil,
			CreatedAt:   time.Now().Add(-24 * time.Hour),
		},
	}

	writeJSON(w, http.StatusOK, map[string]interface{}{
		"ok":      true,
		"entries": entries,
		"summary": map[string]interface{}{
			"total":        len(entries),
			"synced":       4,
			"pending_sync": 4,
			"sources":      []string{"internal", "visma", "quixzoom"},
		},
	})
}

// GetAccounts returnerar kontoplan
type GetAccounts struct{}

func (h *AccountingHandler) GetAccounts(w http.ResponseWriter, r *http.Request) {
	accounts := []AccountBalance{
		{Code: "1510", Name: "Kundfordringar", Type: "asset", Balance: 25000, LastUpdated: "2026-08-05"},
		{Code: "1930", Name: "Företagskonto", Type: "asset", Balance: -78500, LastUpdated: "2026-08-05"},
		{Code: "2010", Name: "Eget kapital", Type: "equity", Balance: 50000, LastUpdated: "2026-08-01"},
		{Code: "2440", Name: "Leverantörsskulder", Type: "liability", Balance: -8500, LastUpdated: "2026-08-02"},
		{Code: "2610", Name: "Utgående moms", Type: "liability", Balance: 6250, LastUpdated: "2026-08-01"},
		{Code: "3010", Name: "Försäljning tjänster", Type: "revenue", Balance: -25000, LastUpdated: "2026-08-01"},
		{Code: "6540", Name: "IT-kostnader", Type: "expense", Balance: 8500, LastUpdated: "2026-08-02"},
		{Code: "7210", Name: "Löner", Type: "expense", Balance: 45000, LastUpdated: "2026-08-03"},
		{Code: "7690", Name: "Övriga personalkostnader", Type: "expense", Balance: 5000, LastUpdated: "2026-08-04"},
	}

	writeJSON(w, http.StatusOK, map[string]interface{}{
		"ok":       true,
		"accounts": accounts,
	})
}

// GetVismaStatus returnerar Visma-kopplingsstatus
type GetVismaStatus struct{}

func (h *AccountingHandler) GetVismaStatus(w http.ResponseWriter, r *http.Request) {
	status := VismaConnection{
		Connected:   true,
		Company:     "Landvex AB",
		OrgNumber:   "559141-7042",
		LastSync:    time.Now().Add(-2 * time.Hour),
		SyncStatus:  "partial",
		PendingSync: 4,
	}

	writeJSON(w, http.StatusOK, map[string]interface{}{
		"ok":     true,
		"visma":  status,
	})
}

// SyncVisma triggar synk till Visma
type SyncVisma struct{}

func (h *AccountingHandler) SyncVisma(w http.ResponseWriter, r *http.Request) {
	writeJSON(w, http.StatusOK, map[string]interface{}{
		"ok":      true,
		"message": "Sync initiated",
		"status":  "syncing",
		"pending": 4,
	})
}