package handlers

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

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

type SupportHandler struct {
	DB *sql.DB
}

func NewSupportHandler(db *sql.DB) *SupportHandler {
	return &SupportHandler{DB: db}
}

type Ticket struct {
	ID          string     `json:"id"`
	CustomerID  *string    `json:"customer_id"`
	ContactID   *string    `json:"contact_id"`
	Subject     string     `json:"subject"`
	Description string     `json:"description"`
	Status      string     `json:"status"`
	Priority    string     `json:"priority"`
	Category    string     `json:"category"`
	Source      string     `json:"source"`
	AssignedTo  *string    `json:"assigned_to"`
	ResolvedAt  *time.Time `json:"resolved_at"`
	Resolution  string     `json:"resolution"`
	CreatedAt   time.Time  `json:"created_at"`
	UpdatedAt   time.Time  `json:"updated_at"`
}

type TicketComment struct {
	ID         string    `json:"id"`
	TicketID   string    `json:"ticket_id"`
	Content    string    `json:"content"`
	IsInternal bool      `json:"is_internal"`
	CreatedBy  *string   `json:"created_by"`
	CreatedAt  time.Time `json:"created_at"`
}

func (h *SupportHandler) ListTickets(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, subject, description, status, priority, category, source, assigned_to, resolved_at, resolution, created_at, updated_at
		FROM boc_tickets
		WHERE status = $1
		ORDER BY 
			CASE priority
				WHEN 'critical' THEN 1
				WHEN 'high' THEN 2
				WHEN 'medium' THEN 3
				WHEN 'low' THEN 4
				ELSE 5
			END,
			created_at DESC
		LIMIT 100
	`, status)
	if err != nil {
		writeError(w, http.StatusInternalServerError, "database error")
		return
	}
	defer rows.Close()

	tickets := []Ticket{}
	for rows.Next() {
		var t Ticket
		if err := rows.Scan(&t.ID, &t.CustomerID, &t.ContactID, &t.Subject, &t.Description,
			&t.Status, &t.Priority, &t.Category, &t.Source, &t.AssignedTo, &t.ResolvedAt,
			&t.Resolution, &t.CreatedAt, &t.UpdatedAt); err != nil {
			continue
		}
		tickets = append(tickets, t)
	}

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

func (h *SupportHandler) CreateTicket(w http.ResponseWriter, r *http.Request) {
	var req Ticket
	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_tickets (customer_id, contact_id, subject, description, status, priority, category, source)
		VALUES ($1, $2, $3, $4, $5, $6, $7, $8)
		RETURNING id
	`, req.CustomerID, req.ContactID, req.Subject, req.Description, req.Status,
		req.Priority, req.Category, req.Source).Scan(&id)

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

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

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

	var t Ticket
	err := h.DB.QueryRow(`
		SELECT id, customer_id, contact_id, subject, description, status, priority, category, source, assigned_to, resolved_at, resolution, created_at, updated_at
		FROM boc_tickets WHERE id = $1
	`, id).Scan(&t.ID, &t.CustomerID, &t.ContactID, &t.Subject, &t.Description,
		&t.Status, &t.Priority, &t.Category, &t.Source, &t.AssignedTo, &t.ResolvedAt,
		&t.Resolution, &t.CreatedAt, &t.UpdatedAt)

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

	// Get comments
	rows, err := h.DB.Query(`
		SELECT id, ticket_id, content, is_internal, created_by, created_at
		FROM boc_ticket_comments
		WHERE ticket_id = $1
		ORDER BY created_at ASC
	`, id)
	if err != nil {
		writeError(w, http.StatusInternalServerError, "database error")
		return
	}
	defer rows.Close()

	comments := []TicketComment{}
	for rows.Next() {
		var c TicketComment
		if err := rows.Scan(&c.ID, &c.TicketID, &c.Content, &c.IsInternal, &c.CreatedBy, &c.CreatedAt); err != nil {
			continue
		}
		comments = append(comments, c)
	}

	writeJSON(w, http.StatusOK, map[string]interface{}{
		"ticket":   t,
		"comments": comments,
	})
}

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

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

	_, err := h.DB.Exec(`
		UPDATE boc_tickets
		SET customer_id = $1, contact_id = $2, subject = $3, description = $4,
		    status = $5, priority = $6, category = $7, source = $8,
		    assigned_to = $9, resolved_at = $10, resolution = $11
		WHERE id = $12
	`, req.CustomerID, req.ContactID, req.Subject, req.Description, req.Status,
		req.Priority, req.Category, req.Source, req.AssignedTo, req.ResolvedAt,
		req.Resolution, id)

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

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

func (h *SupportHandler) AddComment(w http.ResponseWriter, r *http.Request) {
	ticketID := chi.URLParam(r, "id")

	var req TicketComment
	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_ticket_comments (ticket_id, content, is_internal)
		VALUES ($1, $2, $3)
		RETURNING id
	`, ticketID, req.Content, req.IsInternal).Scan(&id)

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

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

func (h *SupportHandler) GetCSAT(w http.ResponseWriter, r *http.Request) {
	// TODO: Implement actual CSAT calculation from ticket ratings
	writeJSON(w, http.StatusOK, map[string]interface{}{
		"csat_score":    4.2,
		"total_ratings": 156,
		"response_rate": 0.78,
	})
}