package api

import (
	"encoding/base64"
	"encoding/json"
	"fmt"
	"io"
	"log"
	"net/http"

	"VerifactuMidAPI/internal"
	"VerifactuMidAPI/internal/cert"
	"VerifactuMidAPI/internal/config"
	"VerifactuMidAPI/internal/crypto"
	"VerifactuMidAPI/internal/formats"
)

type RegisterInput struct {
	CertName          string `json:"cert_name"`
	CertPath          string `json:"cert_path"`
	PasswordEncrypted string `json:"password_encrypted"`
}

type Handler struct {
	cfg        *config.Config
	cert       *cert.Storage
	crypto     *crypto.KeyPair
	facturaSvc *internal.FacturaService
}

func New(cfg *config.Config, certStorage *cert.Storage, keyPair *crypto.KeyPair, facturaSvc *internal.FacturaService) *Handler {
	return &Handler{
		cfg:        cfg,
		cert:       certStorage,
		crypto:     keyPair,
		facturaSvc: facturaSvc,
	}
}

func (h *Handler) GetPublicKey(w http.ResponseWriter, r *http.Request) {
	if r.Method != http.MethodGet {
		http.Error(w, "method not allowed", http.StatusMethodNotAllowed)
		return
	}

	pubPEM, err := h.crypto.PublicKeyPEM()
	if err != nil {
		http.Error(w, "failed to get public key", http.StatusInternalServerError)
		return
	}

	w.Header().Set("Content-Type", "application/json")
	w.Write([]byte(fmt.Sprintf(`{"public_key":"%s"}`, base64.StdEncoding.EncodeToString(pubPEM))))
}

func (h *Handler) RegisterCert(w http.ResponseWriter, r *http.Request) {
	if r.Method != http.MethodPost {
		http.Error(w, "method not allowed", http.StatusMethodNotAllowed)
		return
	}

	body, err := io.ReadAll(r.Body)
	if err != nil {
		http.Error(w, "failed to read body", http.StatusBadRequest)
		return
	}

	var input RegisterInput
	if err := json.Unmarshal(body, &input); err != nil {
		w.Header().Set("Content-Type", "application/json")
		w.Write([]byte(`{"success":false,"error":"invalid_json"}`))
		return
	}

	if input.CertName == "" || input.CertPath == "" || input.PasswordEncrypted == "" {
		w.Header().Set("Content-Type", "application/json")
		w.Write([]byte(`{"success":false,"error":"missing_fields"}`))
		return
	}

	decodedPass, err := base64.StdEncoding.DecodeString(input.PasswordEncrypted)
	if err != nil {
		w.Header().Set("Content-Type", "application/json")
		w.Write([]byte(`{"success":false,"error":"invalid_password_encrypted"}`))
		return
	}

	plainPassBytes, err := h.crypto.Decrypt(decodedPass)
	if err != nil {
		w.Header().Set("Content-Type", "application/json")
		w.Write([]byte(`{"success":false,"error":"decrypt_failed"}`))
		return
	}

	plainPass := string(plainPassBytes)

	validation := cert.ValidateP12(input.CertPath, plainPass)
	if !validation.Valid {
		resp, _ := json.Marshal(map[string]interface{}{
			"success": false,
			"error":   validation.Error,
			"cert":    validation.CertInfo,
		})
		w.Header().Set("Content-Type", "application/json")
		w.Write(resp)
		return
	}

	tempPath, err := h.cert.StoreTemp(input.CertName, input.CertPath, plainPass)
	if err != nil {
		h.cert.DeleteTemp(tempPath)
		w.Header().Set("Content-Type", "application/json")
		w.Write([]byte(`{"success":false,"error":"temp_storage_failed"}`))
		return
	}

	if len(validation.Warnings) > 0 {
		storedPath, err := h.cert.MoveToPerm(input.CertName, tempPath, plainPass)
		if err != nil {
			h.cert.DeleteTemp(tempPath)
			w.Header().Set("Content-Type", "application/json")
			w.Write([]byte(`{"success":false,"error":"storage_failed"}`))
			return
		}

		tokenData, err := h.cert.GenerateToken(input.CertName, storedPath, plainPass)
		if err != nil {
			w.Header().Set("Content-Type", "application/json")
			w.Write([]byte(`{"success":false,"error":"token_generation_failed"}`))
			return
		}

		resp, _ := json.Marshal(map[string]interface{}{
			"success":  true,
			"cert":     validation.CertInfo,
			"token":    tokenData.Token,
			"warnings": validation.Warnings,
		})
		w.Header().Set("Content-Type", "application/json")
		w.Write(resp)
		return
	}

	storedPath, err := h.cert.MoveToPerm(input.CertName, tempPath, plainPass)
	if err != nil {
		h.cert.DeleteTemp(tempPath)
		w.Header().Set("Content-Type", "application/json")
		w.Write([]byte(`{"success":false,"error":"storage_failed"}`))
		return
	}

	tokenData, err := h.cert.GenerateToken(input.CertName, storedPath, plainPass)
	if err != nil {
		w.Header().Set("Content-Type", "application/json")
		w.Write([]byte(`{"success":false,"error":"token_generation_failed"}`))
		return
	}

	resp, _ := json.Marshal(map[string]interface{}{
		"success": true,
		"cert":    validation.CertInfo,
		"token":   tokenData.Token,
	})
	w.Header().Set("Content-Type", "application/json")
	w.Write(resp)
}

func (h *Handler) HandleFacturas(w http.ResponseWriter, r *http.Request) {
	if r.Method != http.MethodPost {
		http.Error(w, "method not allowed", http.StatusMethodNotAllowed)
		return
	}

	body, err := io.ReadAll(r.Body)
	if err != nil {
		http.Error(w, "failed to read body", http.StatusBadRequest)
		return
	}

	log.Printf("facturas request: %s", string(body))

	output, _ := h.facturaSvc.ProcessAlta(body)

	log.Printf("facturas output:%+v", output)

	resp, _ := json.Marshal(output)
	w.Header().Set("Content-Type", "application/json")
	w.Write(resp)
}

func (h *Handler) HandleFacturasAnular(w http.ResponseWriter, r *http.Request) {
	if r.Method != http.MethodPost {
		http.Error(w, "method not allowed", http.StatusMethodNotAllowed)
		return
	}

	body, err := io.ReadAll(r.Body)
	if err != nil {
		http.Error(w, "failed to read body", http.StatusBadRequest)
		return
	}

	var input internal.AnulacionInput
	if err := json.Unmarshal(body, &input); err != nil {
		w.Header().Set("Content-Type", "application/json")
		w.Write([]byte(`{"success":false,"error":"invalid_json"}`))
		return
	}

	output, _ := h.facturaSvc.ProcessAnulacion(input)

	resp, _ := json.Marshal(output)
	w.Header().Set("Content-Type", "application/json")
	w.Write(resp)
}

func (h *Handler) ListFormats(w http.ResponseWriter, r *http.Request) {
	if r.Method != http.MethodGet {
		http.Error(w, "method not allowed", http.StatusMethodNotAllowed)
		return
	}

	available := formats.Available()
	resp, _ := json.Marshal(map[string]interface{}{
		"formats": available,
	})
	w.Header().Set("Content-Type", "application/json")
	w.Write(resp)
}