package handlers

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

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

type CRMHandler struct {
	DB *sql.DB
}

func NewCRMHandler(db *sql.DB) *CRMHandler {
	return &CRMHandler{DB: db}
}

type Customer struct {
	ID        string     `json:"id"`
	Name      string     `json:"name"`
	Email     string     `json:"email"`
	Phone     string     `json:"phone"`
	Company   string     `json:"company"`
	OrgNumber string     `json:"org_number"`
	Status    string     `json:"status"`
	Source    string     `json:"source"`
	Tags      []string   `json:"tags"`
	AssignedTo *string   `json:"assigned_to"`
	CreatedAt time.Time  `json:"created_at"`
	UpdatedAt time.Time  `json:"updated_at"`
}

type CustomerInteraction struct {
	ID          string                 `json:"id"`
	CustomerID  string                 `json:"customer_id"`
	Type        string                 `json:"type"`
	Direction   string                 `json:"direction"`
	Subject     string                 `json:"subject"`
	Content     string                 `json:"content"`
	Metadata    map[string]interface{} `json:"metadata"`
	CreatedBy   *string                `json:"created_by"`
	CreatedAt   time.Time              `json:"created_at"`
}

type PipelineStage struct {
	Stage string  `json:"stage"`
	Count int     `json:"count"`
	Value float64 `json:"value"`
}

func (h *CRMHandler) ListCustomers(w http.ResponseWriter, r *http.Request) {
	status := r.URL.Query().Get("status")
	if status == "" {
		status = "active"
	}

	rows, err := h.DB.Query(`
		SELECT id, name, email, phone, company, org_number, status, source, tags, assigned_to, created_at, updated_at
		FROM boc_customers
		WHERE status = $1
		ORDER BY created_at DESC
		LIMIT 100
	`, status)
	if err != nil {
		writeError(w, http.StatusInternalServerError, "database error")
		return
	}
	defer rows.Close()

	customers := []Customer{}
	for rows.Next() {
		var c Customer
		if err := rows.Scan(&c.ID, &c.Name, &c.Email, &c.Phone, &c.Company, &c.OrgNumber,
			&c.Status, &c.Source, &c.Tags, &c.AssignedTo, &c.CreatedAt, &c.UpdatedAt); err != nil {
			continue
		}
		customers = append(customers, c)
	}

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

func (h *CRMHandler) CreateCustomer(w http.ResponseWriter, r *http.Request) {
	var req Customer
	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_customers (name, email, phone, company, org_number, status, source, tags)
		VALUES ($1, $2, $3, $4, $5, $6, $7, $8)
		RETURNING id
	`, req.Name, req.Email, req.Phone, req.Company, req.OrgNumber, req.Status, req.Source, req.Tags).Scan(&id)

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

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

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

	var c Customer
	err := h.DB.QueryRow(`
		SELECT id, name, email, phone, company, org_number, status, source, tags, assigned_to, created_at, updated_at
		FROM boc_customers WHERE id = $1
	`, id).Scan(&c.ID, &c.Name, &c.Email, &c.Phone, &c.Company, &c.OrgNumber,
		&c.Status, &c.Source, &c.Tags, &c.AssignedTo, &c.CreatedAt, &c.UpdatedAt)

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

	writeJSON(w, http.StatusOK, c)
}

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

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

	_, err := h.DB.Exec(`
		UPDATE boc_customers
		SET name = $1, email = $2, phone = $3, company = $4, org_number = $5,
		    status = $6, source = $7, tags = $8, assigned_to = $9
		WHERE id = $10
	`, req.Name, req.Email, req.Phone, req.Company, req.OrgNumber,
		req.Status, req.Source, req.Tags, req.AssignedTo, id)

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

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

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

	_, err := h.DB.Exec(`DELETE FROM boc_customers WHERE id = $1`, id)
	if err != nil {
		writeError(w, http.StatusInternalServerError, "failed to delete customer")
		return
	}

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

func (h *CRMHandler) ListLeads(w http.ResponseWriter, r *http.Request) {
	rows, err := h.DB.Query(`
		SELECT id, name, email, phone, company, org_number, status, source, tags, assigned_to, created_at, updated_at
		FROM boc_customers
		WHERE status = 'lead'
		ORDER BY created_at DESC
	`)
	if err != nil {
		writeError(w, http.StatusInternalServerError, "database error")
		return
	}
	defer rows.Close()

	leads := []Customer{}
	for rows.Next() {
		var c Customer
		if err := rows.Scan(&c.ID, &c.Name, &c.Email, &c.Phone, &c.Company, &c.OrgNumber,
			&c.Status, &c.Source, &c.Tags, &c.AssignedTo, &c.CreatedAt, &c.UpdatedAt); err != nil {
			continue
		}
		leads = append(leads, c)
	}

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

func (h *CRMHandler) GetPipeline(w http.ResponseWriter, r *http.Request) {
	rows, err := h.DB.Query(`
		SELECT stage, COUNT(*), COALESCE(SUM(value), 0)
		FROM boc_deals
		WHERE status = 'open'
		GROUP BY stage
		ORDER BY 
			CASE stage
				WHEN 'prospect' THEN 1
				WHEN 'qualified' THEN 2
				WHEN 'proposal' THEN 3
				WHEN 'negotiation' THEN 4
				WHEN 'closed_won' THEN 5
				ELSE 6
			END
	`)
	if err != nil {
		writeError(w, http.StatusInternalServerError, "database error")
		return
	}
	defer rows.Close()

	stages := []PipelineStage{}
	for rows.Next() {
		var s PipelineStage
		if err := rows.Scan(&s.Stage, &s.Count, &s.Value); err != nil {
			continue
		}
		stages = append(stages, s)
	}

	writeJSON(w, http.StatusOK, map[string]interface{}{
		"pipeline": stages,
	})
}

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

	metadata, _ := json.Marshal(req.Metadata)

	var id string
	err := h.DB.QueryRow(`
		INSERT INTO boc_customer_interactions (customer_id, type, direction, subject, content, metadata)
		VALUES ($1, $2, $3, $4, $5, $6)
		RETURNING id
	`, req.CustomerID, req.Type, req.Direction, req.Subject, req.Content, metadata).Scan(&id)

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

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

func (h *CRMHandler) GetCustomerInteractions(w http.ResponseWriter, r *http.Request) {
	customerID := chi.URLParam(r, "id")

	rows, err := h.DB.Query(`
		SELECT id, customer_id, type, direction, subject, content, metadata, created_by, created_at
		FROM boc_customer_interactions
		WHERE customer_id = $1
		ORDER BY created_at DESC
	`, customerID)
	if err != nil {
		writeError(w, http.StatusInternalServerError, "database error")
		return
	}
	defer rows.Close()

	interactions := []CustomerInteraction{}
	for rows.Next() {
		var i CustomerInteraction
		var metadata []byte
		if err := rows.Scan(&i.ID, &i.CustomerID, &i.Type, &i.Direction, &i.Subject,
			&i.Content, &metadata, &i.CreatedBy, &i.CreatedAt); err != nil {
			continue
		}
		json.Unmarshal(metadata, &i.Metadata)
		interactions = append(interactions, i)
	}

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