package handler

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

	"git.g3e.fr/H6N/account/internal/store"
	"github.com/jackc/pgx/v5"
)

type AccountHandler struct {
	store *store.Store
}

func NewAccountHandler(s *store.Store) *AccountHandler {
	return &AccountHandler{store: s}
}

func (h *AccountHandler) RegisterRoutes(mux *http.ServeMux) {
	// Comptes maîtres
	mux.HandleFunc("GET /accounts", h.list)
	mux.HandleFunc("POST /accounts", h.create)
	mux.HandleFunc("GET /accounts/{id}", h.get)
	mux.HandleFunc("PUT /accounts/{id}", h.update)
	mux.HandleFunc("DELETE /accounts/{id}", h.delete)

	// Enveloppes (sous-comptes)
	mux.HandleFunc("GET /accounts/{id}/envelopes", h.listEnvelopes)
	mux.HandleFunc("POST /accounts/{id}/envelopes", h.createEnvelope)
	mux.HandleFunc("PUT /envelopes/{id}", h.updateEnvelope)
	mux.HandleFunc("DELETE /envelopes/{id}", h.deleteEnvelope)
}

// --- Comptes maîtres ---

func (h *AccountHandler) list(w http.ResponseWriter, r *http.Request) {
	ownerID, ok := requireOwner(w, r)
	if !ok {
		return
	}
	accounts, err := h.store.ListAccounts(r.Context(), ownerID)
	if err != nil {
		writeError(w, http.StatusInternalServerError, "failed to list accounts")
		return
	}
	writeJSON(w, http.StatusOK, accounts)
}

func (h *AccountHandler) get(w http.ResponseWriter, r *http.Request) {
	ownerID, ok := requireOwner(w, r)
	if !ok {
		return
	}
	id, err := parseID(r)
	if err != nil {
		writeError(w, http.StatusBadRequest, "invalid id")
		return
	}
	if err := h.store.VerifyAccountOwner(r.Context(), id, ownerID); errors.Is(err, pgx.ErrNoRows) {
		writeError(w, http.StatusNotFound, "account not found")
		return
	} else if err != nil {
		writeError(w, http.StatusInternalServerError, "failed to get account")
		return
	}
	account, err := h.store.GetAccountWithEnvelopes(r.Context(), id)
	if errors.Is(err, pgx.ErrNoRows) {
		writeError(w, http.StatusNotFound, "account not found")
		return
	}
	if err != nil {
		writeError(w, http.StatusInternalServerError, "failed to get account")
		return
	}
	writeJSON(w, http.StatusOK, account)
}

func (h *AccountHandler) create(w http.ResponseWriter, r *http.Request) {
	ownerID, ok := requireOwner(w, r)
	if !ok {
		return
	}
	var p store.CreateAccountParams
	if err := json.NewDecoder(r.Body).Decode(&p); err != nil {
		writeError(w, http.StatusBadRequest, "invalid request body")
		return
	}
	if p.Nom == "" || p.Type == "" {
		writeError(w, http.StatusBadRequest, "nom and type are required")
		return
	}
	account, err := h.store.CreateAccount(r.Context(), p, ownerID)
	if err != nil {
		writeError(w, http.StatusInternalServerError, "failed to create account")
		return
	}
	writeJSON(w, http.StatusCreated, account)
}

func (h *AccountHandler) update(w http.ResponseWriter, r *http.Request) {
	ownerID, ok := requireOwner(w, r)
	if !ok {
		return
	}
	id, err := parseID(r)
	if err != nil {
		writeError(w, http.StatusBadRequest, "invalid id")
		return
	}
	var p store.CreateAccountParams
	if err := json.NewDecoder(r.Body).Decode(&p); err != nil {
		writeError(w, http.StatusBadRequest, "invalid request body")
		return
	}
	account, err := h.store.UpdateAccount(r.Context(), id, p, ownerID)
	if errors.Is(err, pgx.ErrNoRows) {
		writeError(w, http.StatusNotFound, "account not found")
		return
	}
	if err != nil {
		writeError(w, http.StatusInternalServerError, "failed to update account")
		return
	}
	writeJSON(w, http.StatusOK, account)
}

func (h *AccountHandler) delete(w http.ResponseWriter, r *http.Request) {
	ownerID, ok := requireOwner(w, r)
	if !ok {
		return
	}
	id, err := parseID(r)
	if err != nil {
		writeError(w, http.StatusBadRequest, "invalid id")
		return
	}
	if err := h.store.DeleteAccount(r.Context(), id, ownerID); err != nil {
		writeError(w, http.StatusInternalServerError, "failed to delete account")
		return
	}
	w.WriteHeader(http.StatusNoContent)
}

// --- Enveloppes ---

func (h *AccountHandler) listEnvelopes(w http.ResponseWriter, r *http.Request) {
	ownerID, ok := requireOwner(w, r)
	if !ok {
		return
	}
	id, err := parseID(r)
	if err != nil {
		writeError(w, http.StatusBadRequest, "invalid id")
		return
	}
	if err := h.store.VerifyAccountOwner(r.Context(), id, ownerID); errors.Is(err, pgx.ErrNoRows) {
		writeError(w, http.StatusNotFound, "account not found")
		return
	} else if err != nil {
		writeError(w, http.StatusInternalServerError, "failed to verify account")
		return
	}
	envelopes, err := h.store.ListEnvelopes(r.Context(), id)
	if err != nil {
		writeError(w, http.StatusInternalServerError, "failed to list envelopes")
		return
	}
	writeJSON(w, http.StatusOK, envelopes)
}

func (h *AccountHandler) createEnvelope(w http.ResponseWriter, r *http.Request) {
	ownerID, ok := requireOwner(w, r)
	if !ok {
		return
	}
	masterID, err := parseID(r)
	if err != nil {
		writeError(w, http.StatusBadRequest, "invalid id")
		return
	}
	var p store.CreateEnvelopeParams
	if err := json.NewDecoder(r.Body).Decode(&p); err != nil {
		writeError(w, http.StatusBadRequest, "invalid request body")
		return
	}
	if p.Nom == "" {
		writeError(w, http.StatusBadRequest, "nom is required")
		return
	}
	envelope, err := h.store.CreateEnvelope(r.Context(), masterID, p, ownerID)
	if errors.Is(err, pgx.ErrNoRows) {
		writeError(w, http.StatusNotFound, "account not found")
		return
	}
	if errors.Is(err, store.ErrMasterIsSubAccount) {
		writeError(w, http.StatusBadRequest, "account cannot itself be an envelope")
		return
	}
	if err != nil {
		writeError(w, http.StatusInternalServerError, "failed to create envelope")
		return
	}
	writeJSON(w, http.StatusCreated, envelope)
}

func (h *AccountHandler) updateEnvelope(w http.ResponseWriter, r *http.Request) {
	ownerID, ok := requireOwner(w, r)
	if !ok {
		return
	}
	id, err := parseID(r)
	if err != nil {
		writeError(w, http.StatusBadRequest, "invalid id")
		return
	}
	var p store.CreateEnvelopeParams
	if err := json.NewDecoder(r.Body).Decode(&p); err != nil {
		writeError(w, http.StatusBadRequest, "invalid request body")
		return
	}
	envelope, err := h.store.UpdateEnvelope(r.Context(), id, p, ownerID)
	if errors.Is(err, pgx.ErrNoRows) {
		writeError(w, http.StatusNotFound, "envelope not found")
		return
	}
	if err != nil {
		writeError(w, http.StatusInternalServerError, "failed to update envelope")
		return
	}
	writeJSON(w, http.StatusOK, envelope)
}

func (h *AccountHandler) deleteEnvelope(w http.ResponseWriter, r *http.Request) {
	ownerID, ok := requireOwner(w, r)
	if !ok {
		return
	}
	id, err := parseID(r)
	if err != nil {
		writeError(w, http.StatusBadRequest, "invalid id")
		return
	}
	if err := h.store.DeleteAccount(r.Context(), id, ownerID); err != nil {
		writeError(w, http.StatusInternalServerError, "failed to delete envelope")
		return
	}
	w.WriteHeader(http.StatusNoContent)
}