package handlers

import (
	"database/sql"
	"encoding/json"
	"net/http"
	"time"

	"github.com/go-chi/chi/v5"
)

type SalesHandler struct {
	DB *sql.DB
}

func NewSalesHandler(db *sql.DB) *SalesHandler {
	return &SalesHandler{DB: db}
}

type Deal struct {
	ID             string     `json:"id"`
	CustomerID     string     `json:"customer_id"`
	ContactID      *string    `json:"contact_id"`
	Name           string     `json:"name"`
	Description    string     `json:"description"`
	Value          float64    `json:"value"`
	Currency       string     `json:"currency"`
	Status         string     `json:"status"`
	Stage          string     `json:"stage"`
	Probability    int        `json:"probability"`
	ExpectedClose  *time.Time `json:"expected_close"`
	ActualClose    *time.Time `json:"actual_close"`
	AssignedTo     *string    `json:"assigned_to"`
	CreatedAt      time.Time  `json:"created_at"`
	UpdatedAt      time.Time  `json:"updated_at"`
}

type Product struct {
	ID           string  `json:"id"`
	Name         string  `json:"name"`
	Description  string  `json:"description"`
	SKU          string  `json:"sku"`
	Price        float64 `json:"price"`
	Currency     string  `json:"currency"`
	Unit         string  `json:"unit"`
	IsRecurring  bool    `json:"is_recurring"`
	BillingPeriod string `json:"billing_period"`
	Status       string  `json:"status"`
}

func (h *SalesHandler) ListDeals(w http.ResponseWriter, r *http.Request) {
	status := r.URL.Query().Get("status")
	if status == "" {
		status = "open"
	}

	rows, err := h.DB.Query(`
		SELECT id, customer_id, contact_id, name, description, value, currency, status, stage, probability, expected_close, actual_close, assigned_to, created_at, updated_at
		FROM boc_deals
		WHERE status = $1
		ORDER BY created_at DESC
		LIMIT 100
	`, status)
	if err != nil {
		writeError(w, http.StatusInternalServerError, "database error")
		return
	}
	defer rows.Close()

	deals := []Deal{}
	for rows.Next() {
		var d Deal
		if err := rows.Scan(&d.ID, &d.CustomerID, &d.ContactID, &d.Name, &d.Description, &d.Value,
			&d.Currency, &d.Status, &d.Stage, &d.Probability, &d.ExpectedClose, &d.ActualClose,
			&d.AssignedTo, &d.CreatedAt, &d.UpdatedAt); err != nil {
			continue
		}
		deals = append(deals, d)
	}

	writeJSON(w, http.StatusOK, map[string]interface{}{
		"deals": deals,
		"total": len(deals),
	})
}

func (h *SalesHandler) CreateDeal(w http.ResponseWriter, r *http.Request) {
	var req Deal
	if err := json.NewDecoder(r.Body).Decode(&req); err != nil {
		writeError(w, http.StatusBadRequest, "invalid request")
		return
	}

	var id string
	err := h.DB.QueryRow(`
		INSERT INTO boc_deals (customer_id, contact_id, name, description, value, currency, status, stage, probability, expected_close)
		VALUES ($1, $2, $3, $4, $5, $6, $7, $8, $9, $10)
		RETURNING id
	`, req.CustomerID, req.ContactID, req.Name, req.Description, req.Value, req.Currency,
		req.Status, req.Stage, req.Probability, req.ExpectedClose).Scan(&id)

	if err != nil {
		writeError(w, http.StatusInternalServerError, "failed to create deal")
		return
	}

	writeJSON(w, http.StatusCreated, map[string]interface{}{
		"id":      id,
		"message": "Deal created",
	})
}

func (h *SalesHandler) GetDeal(w http.ResponseWriter, r *http.Request) {
	id := chi.URLParam(r, "id")

	var d Deal
	err := h.DB.QueryRow(`
		SELECT id, customer_id, contact_id, name, description, value, currency, status, stage, probability, expected_close, actual_close, assigned_to, created_at, updated_at
		FROM boc_deals WHERE id = $1
	`, id).Scan(&d.ID, &d.CustomerID, &d.ContactID, &d.Name, &d.Description, &d.Value,
		&d.Currency, &d.Status, &d.Stage, &d.Probability, &d.ExpectedClose, &d.ActualClose,
		&d.AssignedTo, &d.CreatedAt, &d.UpdatedAt)

	if err == sql.ErrNoRows {
		writeError(w, http.StatusNotFound, "deal not found")
		return
	}
	if err != nil {
		writeError(w, http.StatusInternalServerError, "database error")
		return
	}

	writeJSON(w, http.StatusOK, d)
}

func (h *SalesHandler) UpdateDeal(w http.ResponseWriter, r *http.Request) {
	id := chi.URLParam(r, "id")

	var req Deal
	if err := json.NewDecoder(r.Body).Decode(&req); err != nil {
		writeError(w, http.StatusBadRequest, "invalid request")
		return
	}

	_, err := h.DB.Exec(`
		UPDATE boc_deals
		SET customer_id = $1, contact_id = $2, name = $3, description = $4, value = $5,
		    currency = $6, status = $7, stage = $8, probability = $9, expected_close = $10,
		    actual_close = $11, assigned_to = $12
		WHERE id = $13
	`, req.CustomerID, req.ContactID, req.Name, req.Description, req.Value, req.Currency,
		req.Status, req.Stage, req.Probability, req.ExpectedClose, req.ActualClose,
		req.AssignedTo, id)

	if err != nil {
		writeError(w, http.StatusInternalServerError, "failed to update deal")
		return
	}

	writeJSON(w, http.StatusOK, map[string]interface{}{
		"message": "Deal updated",
	})
}

func (h *SalesHandler) GetMRR(w http.ResponseWriter, r *http.Request) {
	var mrr float64
	err := h.DB.QueryRow(`
		SELECT COALESCE(SUM(value), 0)
		FROM boc_deals
		WHERE status = 'closed_won'
		AND created_at >= NOW() - INTERVAL '1 month'
	`).Scan(&mrr)
	if err != nil {
		mrr = 0
	}

	writeJSON(w, http.StatusOK, map[string]interface{}{
		"mrr":      mrr,
		"currency": "USD",
	})
}

func (h *SalesHandler) GetARR(w http.ResponseWriter, r *http.Request) {
	var arr float64
	err := h.DB.QueryRow(`
		SELECT COALESCE(SUM(value), 0)
		FROM boc_deals
		WHERE status = 'closed_won'
		AND created_at >= NOW() - INTERVAL '1 year'
	`).Scan(&arr)
	if err != nil {
		arr = 0
	}

	writeJSON(w, http.StatusOK, map[string]interface{}{
		"arr":      arr,
		"currency": "USD",
	})
}

func (h *SalesHandler) ListProducts(w http.ResponseWriter, r *http.Request) {
	rows, err := h.DB.Query(`
		SELECT id, name, description, sku, price, currency, unit, is_recurring, billing_period, status
		FROM boc_products
		WHERE status = 'active'
		ORDER BY name
	`)
	if err != nil {
		writeError(w, http.StatusInternalServerError, "database error")
		return
	}
	defer rows.Close()

	products := []Product{}
	for rows.Next() {
		var p Product
		if err := rows.Scan(&p.ID, &p.Name, &p.Description, &p.SKU, &p.Price, &p.Currency,
			&p.Unit, &p.IsRecurring, &p.BillingPeriod, &p.Status); err != nil {
			continue
		}
		products = append(products, p)
	}

	writeJSON(w, http.StatusOK, map[string]interface{}{
		"products": products,
		"total":    len(products),
	})
}

func (h *SalesHandler) CreateProduct(w http.ResponseWriter, r *http.Request) {
	var req Product
	if err := json.NewDecoder(r.Body).Decode(&req); err != nil {
		writeError(w, http.StatusBadRequest, "invalid request")
		return
	}

	var id string
	err := h.DB.QueryRow(`
		INSERT INTO boc_products (name, description, sku, price, currency, unit, is_recurring, billing_period, status)
		VALUES ($1, $2, $3, $4, $5, $6, $7, $8, 'active')
		RETURNING id
	`, req.Name, req.Description, req.SKU, req.Price, req.Currency, req.Unit,
		req.IsRecurring, req.BillingPeriod).Scan(&id)

	if err != nil {
		writeError(w, http.StatusInternalServerError, "failed to create product")
		return
	}

	writeJSON(w, http.StatusCreated, map[string]interface{}{
		"id":      id,
		"message": "Product created",
	})
}