package handlers

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

	"mgit.msbls.de/m/KanzlAI-mGMT/internal/models"
	"mgit.msbls.de/m/KanzlAI-mGMT/internal/services"
)

// FeeCalculatorHandler handles fee calculation API endpoints.
type FeeCalculatorHandler struct {
	calc *services.FeeCalculator
}

func NewFeeCalculatorHandler(calc *services.FeeCalculator) *FeeCalculatorHandler {
	return &FeeCalculatorHandler{calc: calc}
}

// Calculate handles POST /api/fees/calculate.
func (h *FeeCalculatorHandler) Calculate(w http.ResponseWriter, r *http.Request) {
	var req models.FeeCalculateRequest
	if err := json.NewDecoder(r.Body).Decode(&req); err != nil {
		writeError(w, http.StatusBadRequest, "invalid request body")
		return
	}

	if req.Streitwert <= 0 {
		writeError(w, http.StatusBadRequest, "streitwert must be positive")
		return
	}
	if req.VATRate < 0 || req.VATRate > 1 {
		writeError(w, http.StatusBadRequest, "vat_rate must be between 0 and 1")
		return
	}
	if len(req.Instances) == 0 {
		writeError(w, http.StatusBadRequest, "at least one instance is required")
		return
	}

	resp, err := h.calc.CalculateFullLitigation(req)
	if err != nil {
		writeError(w, http.StatusBadRequest, err.Error())
		return
	}

	writeJSON(w, http.StatusOK, resp)
}

// Schedules handles GET /api/fees/schedules.
func (h *FeeCalculatorHandler) Schedules(w http.ResponseWriter, r *http.Request) {
	writeJSON(w, http.StatusOK, h.calc.GetSchedules())
}