package routes

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

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

	"github.com/felt-app/felt/internal/financial"
	"github.com/felt-app/felt/internal/server/middleware"
)

// FinancialHandler handles financial API routes.
type FinancialHandler struct {
	engine *financial.Engine
}

// NewFinancialHandler creates a new financial route handler.
func NewFinancialHandler(engine *financial.Engine) *FinancialHandler {
	return &FinancialHandler{engine: engine}
}

// RegisterRoutes registers financial routes on the given router.
func (h *FinancialHandler) RegisterRoutes(r chi.Router) {
	r.Route("/tournaments/{id}", func(r chi.Router) {
		// Read-only routes (any authenticated user)
		r.Get("/prize-pool", h.handleGetPrizePool)
		r.Get("/payouts", h.handleGetPayouts)
		r.Get("/payouts/preview", h.handlePreviewPayouts)
		r.Get("/transactions", h.handleGetTransactions)
		r.Get("/transactions/{txId}/receipt", h.handleGetReceipt)

		// Mutation routes (admin or floor)
		r.Group(func(r chi.Router) {
			r.Use(middleware.RequireRole(middleware.RoleFloor))
			r.Post("/bubble-prize", h.handleCreateBubblePrize)
			r.Post("/bubble-prize/{proposalId}/confirm", h.handleConfirmBubblePrize)
			r.Post("/transactions/{txId}/reprint", h.handleReprintReceipt)
		})
	})

	// Season reserves (venue-level, any authenticated user)
	r.Get("/season-reserves", h.handleGetSeasonReserves)
}

// handleGetPrizePool returns the current prize pool summary for a tournament.
func (h *FinancialHandler) handleGetPrizePool(w http.ResponseWriter, r *http.Request) {
	tournamentID := chi.URLParam(r, "id")
	if tournamentID == "" {
		writeError(w, http.StatusBadRequest, "tournament id required")
		return
	}

	summary, err := h.engine.CalculatePrizePool(r.Context(), tournamentID)
	if err != nil {
		writeError(w, http.StatusInternalServerError, err.Error())
		return
	}

	writeJSON(w, http.StatusOK, summary)
}

// handleGetPayouts returns the calculated payout table.
func (h *FinancialHandler) handleGetPayouts(w http.ResponseWriter, r *http.Request) {
	tournamentID := chi.URLParam(r, "id")
	if tournamentID == "" {
		writeError(w, http.StatusBadRequest, "tournament id required")
		return
	}

	payouts, err := h.engine.CalculatePayouts(r.Context(), tournamentID)
	if err != nil {
		writeError(w, http.StatusBadRequest, err.Error())
		return
	}

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

// handlePreviewPayouts returns a preview of payouts without applying them.
func (h *FinancialHandler) handlePreviewPayouts(w http.ResponseWriter, r *http.Request) {
	tournamentID := chi.URLParam(r, "id")
	if tournamentID == "" {
		writeError(w, http.StatusBadRequest, "tournament id required")
		return
	}

	summary, err := h.engine.CalculatePrizePool(r.Context(), tournamentID)
	if err != nil {
		writeError(w, http.StatusInternalServerError, err.Error())
		return
	}

	payouts, err := h.engine.CalculatePayouts(r.Context(), tournamentID)
	if err != nil {
		writeError(w, http.StatusBadRequest, err.Error())
		return
	}

	writeJSON(w, http.StatusOK, map[string]interface{}{
		"prize_pool": summary,
		"payouts":    payouts,
		"preview":    true,
	})
}

// handleGetTransactions returns all transactions for a tournament.
func (h *FinancialHandler) handleGetTransactions(w http.ResponseWriter, r *http.Request) {
	tournamentID := chi.URLParam(r, "id")
	if tournamentID == "" {
		writeError(w, http.StatusBadRequest, "tournament id required")
		return
	}

	txs, err := h.engine.GetTransactions(r.Context(), tournamentID)
	if err != nil {
		writeError(w, http.StatusInternalServerError, err.Error())
		return
	}

	writeJSON(w, http.StatusOK, txs)
}

// handleGetReceipt returns the receipt for a transaction.
func (h *FinancialHandler) handleGetReceipt(w http.ResponseWriter, r *http.Request) {
	txID := chi.URLParam(r, "txId")
	if txID == "" {
		writeError(w, http.StatusBadRequest, "transaction id required")
		return
	}

	receipt, err := h.engine.GetReceipt(r.Context(), txID)
	if err != nil {
		writeError(w, http.StatusNotFound, err.Error())
		return
	}

	writeJSON(w, http.StatusOK, receipt)
}

// handleReprintReceipt returns the receipt with a new print timestamp.
func (h *FinancialHandler) handleReprintReceipt(w http.ResponseWriter, r *http.Request) {
	txID := chi.URLParam(r, "txId")
	if txID == "" {
		writeError(w, http.StatusBadRequest, "transaction id required")
		return
	}

	receipt, err := h.engine.ReprintReceipt(r.Context(), txID)
	if err != nil {
		writeError(w, http.StatusNotFound, err.Error())
		return
	}

	writeJSON(w, http.StatusOK, receipt)
}

type bubblePrizeRequest struct {
	Amount int64 `json:"amount"` // cents
}

// handleCreateBubblePrize creates a bubble prize proposal.
func (h *FinancialHandler) handleCreateBubblePrize(w http.ResponseWriter, r *http.Request) {
	tournamentID := chi.URLParam(r, "id")
	if tournamentID == "" {
		writeError(w, http.StatusBadRequest, "tournament id required")
		return
	}

	var req bubblePrizeRequest
	if err := json.NewDecoder(r.Body).Decode(&req); err != nil {
		writeError(w, http.StatusBadRequest, "invalid JSON: "+err.Error())
		return
	}
	if req.Amount <= 0 {
		writeError(w, http.StatusBadRequest, "amount must be positive")
		return
	}

	proposal, err := h.engine.CalculateBubblePrize(r.Context(), tournamentID, req.Amount)
	if err != nil {
		writeError(w, http.StatusBadRequest, err.Error())
		return
	}

	writeJSON(w, http.StatusCreated, proposal)
}

// handleConfirmBubblePrize confirms a bubble prize proposal.
func (h *FinancialHandler) handleConfirmBubblePrize(w http.ResponseWriter, r *http.Request) {
	tournamentID := chi.URLParam(r, "id")
	proposalIDStr := chi.URLParam(r, "proposalId")

	proposalID, err := strconv.ParseInt(proposalIDStr, 10, 64)
	if err != nil {
		writeError(w, http.StatusBadRequest, "invalid proposal id")
		return
	}

	if err := h.engine.ConfirmBubblePrize(r.Context(), tournamentID, proposalID); err != nil {
		writeError(w, http.StatusBadRequest, err.Error())
		return
	}

	writeJSON(w, http.StatusOK, map[string]string{"status": "confirmed"})
}

// handleGetSeasonReserves returns the season reserve summary.
func (h *FinancialHandler) handleGetSeasonReserves(w http.ResponseWriter, r *http.Request) {
	reserves, err := h.engine.GetSeasonReserves(r.Context())
	if err != nil {
		writeError(w, http.StatusInternalServerError, err.Error())
		return
	}

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