package api

import (
	"encoding/json"
	"net/http"
	"strconv"
	"strings"

	"github.com/fmartingr/ccrm/server/internal/db"
)

// SessionsHandler handles session-related API endpoints.
type SessionsHandler struct {
	DB *db.DB
}

// List handles GET /api/sessions
func (h *SessionsHandler) List(w http.ResponseWriter, r *http.Request) {
	activeOnly := r.URL.Query().Get("active") == "true"

	sessions, err := h.DB.ListSessions(activeOnly)
	if err != nil {
		writeError(w, http.StatusInternalServerError, err.Error())
		return
	}

	if sessions == nil {
		sessions = []*db.Session{}
	}

	writeJSON(w, http.StatusOK, sessions)
}

// Get handles GET /api/sessions/{id}
func (h *SessionsHandler) Get(w http.ResponseWriter, r *http.Request) {
	id := extractPathParam(r, "/api/sessions/")
	if id == "" {
		writeError(w, http.StatusBadRequest, "session ID required")
		return
	}

	// Strip any trailing path segments (like /events)
	if idx := strings.Index(id, "/"); idx >= 0 {
		id = id[:idx]
	}

	session, err := h.DB.GetSession(id)
	if err != nil {
		writeError(w, http.StatusNotFound, "session not found")
		return
	}

	writeJSON(w, http.StatusOK, session)
}

// ListEvents handles GET /api/sessions/{id}/events
func (h *SessionsHandler) ListEvents(w http.ResponseWriter, r *http.Request) {
	// Extract session ID from path
	path := strings.TrimPrefix(r.URL.Path, "/api/sessions/")
	parts := strings.SplitN(path, "/", 2)
	if len(parts) < 1 {
		writeError(w, http.StatusBadRequest, "session ID required")
		return
	}
	sessionID := parts[0]

	limit, _ := strconv.Atoi(r.URL.Query().Get("limit"))
	offset, _ := strconv.Atoi(r.URL.Query().Get("offset"))

	events, err := h.DB.ListEvents(sessionID, limit, offset)
	if err != nil {
		writeError(w, http.StatusInternalServerError, err.Error())
		return
	}

	if events == nil {
		events = []*db.Event{}
	}

	writeJSON(w, http.StatusOK, events)
}

func extractPathParam(r *http.Request, prefix string) string {
	return strings.TrimPrefix(r.URL.Path, prefix)
}

func writeJSON(w http.ResponseWriter, status int, data any) {
	w.Header().Set("Content-Type", "application/json")
	w.WriteHeader(status)
	json.NewEncoder(w).Encode(data)
}

func writeError(w http.ResponseWriter, status int, msg string) {
	w.Header().Set("Content-Type", "application/json")
	w.WriteHeader(status)
	json.NewEncoder(w).Encode(map[string]string{"error": msg})
}