package database_clients

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

	"project/internal/api"
	"project/internal/auth"
)

type Handler struct {
	svc *Service
}

func NewHandler(svc *Service) *Handler {
	return &Handler{svc: svc}
}

// ListDBTypes godoc
//
//	@Summary		List tipe database yang didukung beserta definisi field kredensial
//	@Description	Mengembalikan semua tipe database beserta schema field yang dibutuhkan untuk membuat koneksi. Gunakan untuk render form dinamis di frontend.
//	@Tags			database-clients
//	@Produce		json
//	@Success		200	{object}	api.APIResponse{data=[]DBTypeInfo}
//	@Security		BearerAuth
//	@Router			/api/v1/database-clients/dbtypes [get]
func (h *Handler) ListDBTypes(w http.ResponseWriter, r *http.Request) {
	writeJSON(w, http.StatusOK, api.APIResponse{
		Status:  "success",
		Message: "supported database types",
		Data:    h.svc.ListDBTypes(),
	})
}

// Create godoc
//
//	@Summary		Daftarkan koneksi database baru
//	@Description	Enkripsi credentials dan simpan. Jika sudah ada koneksi dengan identity yang sama, kembalikan yang existing (HTTP 200).
//	@Tags			database-clients
//	@Accept			json
//	@Produce		json
//	@Param			body	body		object{user_id=string,name=string,db_type=string,credentials=object}	true	"Database connection info"
//	@Success		201		{object}	api.APIResponse{data=DBClient}
//	@Success		200		{object}	api.APIResponse{data=DBClient}	"Duplicate — returning existing"
//	@Failure		400		{object}	api.APIResponse
//	@Failure		429		{object}	map[string]string				"Rate limit exceeded"
//	@Failure		500		{object}	api.APIResponse
//	@Security		BearerAuth
//	@Router			/api/v1/database-clients [post]
func (h *Handler) Create(w http.ResponseWriter, r *http.Request) {
	var req struct {
		UserID      string         `json:"user_id"`
		Name        string         `json:"name"`
		DBType      string         `json:"db_type"`
		Credentials map[string]any `json:"credentials"`
	}
	if err := json.NewDecoder(r.Body).Decode(&req); err != nil {
		writeJSON(w, http.StatusBadRequest, api.APIResponse{Status: "error", Message: "invalid request body"})
		return
	}
	if req.UserID == "" || req.Name == "" || req.DBType == "" || req.Credentials == nil {
		writeJSON(w, http.StatusBadRequest, api.APIResponse{Status: "error", Message: "user_id, name, db_type, and credentials are required"})
		return
	}
	if rejectUserMismatch(w, r, req.UserID) {
		return
	}

	client, isDuplicate, err := h.svc.Create(r.Context(), req.UserID, req.Name, req.DBType, req.Credentials)
	if err != nil {
		if errors.Is(err, ErrUnsupportedType) {
			writeJSON(w, http.StatusBadRequest, api.APIResponse{Status: "error", Message: "unsupported database type"})
			return
		}
		slog.Error("database client create failed", "err", err)
		writeJSON(w, http.StatusInternalServerError, api.APIResponse{Status: "error", Message: "internal server error"})
		return
	}

	status := http.StatusCreated
	msg := "database client created"
	if isDuplicate {
		status = http.StatusOK
		msg = "database client already exists"
	}
	writeJSON(w, status, api.APIResponse{Status: "success", Message: msg, Data: client})
}

// List godoc
//
//	@Summary		List koneksi database milik user
//	@Tags			database-clients
//	@Produce		json
//	@Param			user_id	path		string	true	"User ID"
//	@Success		200		{object}	api.APIResponse{data=[]DBClient}
//	@Failure		500		{object}	api.APIResponse
//	@Security		BearerAuth
//	@Router			/api/v1/database-clients/{user_id} [get]
func (h *Handler) List(w http.ResponseWriter, r *http.Request) {
	userID := r.PathValue("user_id")
	if rejectUserMismatch(w, r, userID) {
		return
	}
	clients, err := h.svc.List(r.Context(), userID)
	if err != nil {
		writeJSON(w, http.StatusInternalServerError, api.APIResponse{Status: "error", Message: "internal server error"})
		return
	}
	writeJSON(w, http.StatusOK, api.APIResponse{Status: "success", Message: "database clients", Data: clients})
}

// GetOne godoc
//
//	@Summary		Ambil detail satu koneksi database
//	@Tags			database-clients
//	@Produce		json
//	@Param			user_id		path		string	true	"User ID"
//	@Param			client_id	path		string	true	"Client ID"
//	@Success		200			{object}	api.APIResponse{data=DBClient}
//	@Failure		403			{object}	api.APIResponse
//	@Failure		404			{object}	api.APIResponse
//	@Failure		500			{object}	api.APIResponse
//	@Security		BearerAuth
//	@Router			/api/v1/database-clients/{user_id}/{client_id} [get]
func (h *Handler) GetOne(w http.ResponseWriter, r *http.Request) {
	userID := r.PathValue("user_id")
	if rejectUserMismatch(w, r, userID) {
		return
	}
	clientID := r.PathValue("client_id")
	client, err := h.svc.Get(r.Context(), userID, clientID)
	if err != nil {
		switch {
		case errors.Is(err, ErrNotFound):
			writeJSON(w, http.StatusNotFound, api.APIResponse{Status: "error", Message: "database client not found"})
		case errors.Is(err, ErrForbidden):
			writeJSON(w, http.StatusForbidden, api.APIResponse{Status: "error", Message: "access denied"})
		default:
			writeJSON(w, http.StatusInternalServerError, api.APIResponse{Status: "error", Message: "internal server error"})
		}
		return
	}
	writeJSON(w, http.StatusOK, api.APIResponse{Status: "success", Message: "database client", Data: client})
}

// Update godoc
//
//	@Summary		Update koneksi database
//	@Tags			database-clients
//	@Accept			json
//	@Produce		json
//	@Param			client_id	path		string												true	"Client ID"
//	@Param			user_id		query		string												true	"User ID (ownership check)"
//	@Param			body		body		object{name=string,credentials=object,status=string}	false	"Fields to update"
//	@Success		200			{object}	api.APIResponse{data=DBClient}
//	@Failure		400			{object}	api.APIResponse
//	@Failure		403			{object}	api.APIResponse
//	@Failure		404			{object}	api.APIResponse
//	@Failure		500			{object}	api.APIResponse
//	@Security		BearerAuth
//	@Router			/api/v1/database-clients/{client_id} [put]
func (h *Handler) Update(w http.ResponseWriter, r *http.Request) {
	clientID := r.PathValue("client_id")
	userID := r.URL.Query().Get("user_id")
	if userID == "" {
		writeJSON(w, http.StatusBadRequest, api.APIResponse{Status: "error", Message: "user_id is required"})
		return
	}
	if rejectUserMismatch(w, r, userID) {
		return
	}
	var req struct {
		Name        *string        `json:"name"`
		Credentials map[string]any `json:"credentials"`
		Status      *string        `json:"status"`
	}
	if err := json.NewDecoder(r.Body).Decode(&req); err != nil {
		writeJSON(w, http.StatusBadRequest, api.APIResponse{Status: "error", Message: "invalid request body"})
		return
	}

	client, err := h.svc.Update(r.Context(), clientID, userID, req.Name, req.Credentials, req.Status)
	if err != nil {
		switch {
		case errors.Is(err, ErrNotFound):
			writeJSON(w, http.StatusNotFound, api.APIResponse{Status: "error", Message: "database client not found"})
		case errors.Is(err, ErrForbidden):
			writeJSON(w, http.StatusForbidden, api.APIResponse{Status: "error", Message: "access denied"})
		default:
			writeJSON(w, http.StatusInternalServerError, api.APIResponse{Status: "error", Message: "internal server error"})
		}
		return
	}
	writeJSON(w, http.StatusOK, api.APIResponse{Status: "success", Message: "database client updated", Data: client})
}

// Delete godoc
//
//	@Summary		Hapus koneksi database
//	@Description	Menghapus koneksi dan memicu pembersihan catalog
//	@Tags			database-clients
//	@Produce		json
//	@Param			client_id	path		string	true	"Client ID"
//	@Param			user_id		query		string	true	"User ID (ownership check)"
//	@Success		200			{object}	api.APIResponse
//	@Failure		400			{object}	api.APIResponse
//	@Failure		403			{object}	api.APIResponse
//	@Failure		404			{object}	api.APIResponse
//	@Failure		500			{object}	api.APIResponse
//	@Security		BearerAuth
//	@Router			/api/v1/database-clients/{client_id} [delete]
func (h *Handler) Delete(w http.ResponseWriter, r *http.Request) {
	clientID := r.PathValue("client_id")
	userID := r.URL.Query().Get("user_id")
	if userID == "" {
		writeJSON(w, http.StatusBadRequest, api.APIResponse{Status: "error", Message: "user_id is required"})
		return
	}
	if rejectUserMismatch(w, r, userID) {
		return
	}
	if err := h.svc.Delete(r.Context(), clientID, userID); err != nil {
		switch {
		case errors.Is(err, ErrNotFound):
			writeJSON(w, http.StatusNotFound, api.APIResponse{Status: "error", Message: "database client not found"})
		case errors.Is(err, ErrForbidden):
			writeJSON(w, http.StatusForbidden, api.APIResponse{Status: "error", Message: "access denied"})
		default:
			writeJSON(w, http.StatusInternalServerError, api.APIResponse{Status: "error", Message: "internal server error"})
		}
		return
	}
	writeJSON(w, http.StatusOK, api.APIResponse{Status: "success", Message: "database client deleted"})
}

// Ingest godoc
//
//	@Summary		Introspect schema database dan simpan ke catalog
//	@Tags			database-clients
//	@Produce		json
//	@Param			client_id	path		string	true	"Client ID"
//	@Param			user_id		query		string	true	"User ID (ownership check)"
//	@Success		200			{object}	api.APIResponse
//	@Failure		400			{object}	api.APIResponse
//	@Failure		403			{object}	api.APIResponse
//	@Failure		404			{object}	api.APIResponse
//	@Failure		409			{object}	api.APIResponse	"Client is inactive"
//	@Failure		429			{object}	map[string]string	"Rate limit exceeded"
//	@Failure		500			{object}	api.APIResponse
//	@Security		BearerAuth
//	@Router			/api/v1/database-clients/{client_id}/ingest [post]
func (h *Handler) Ingest(w http.ResponseWriter, r *http.Request) {
	clientID := r.PathValue("client_id")
	userID := r.URL.Query().Get("user_id")
	if userID == "" {
		writeJSON(w, http.StatusBadRequest, api.APIResponse{Status: "error", Message: "user_id is required"})
		return
	}
	if rejectUserMismatch(w, r, userID) {
		return
	}
	schema, err := h.svc.Ingest(r.Context(), clientID, userID)
	if err != nil {
		switch {
		case errors.Is(err, ErrNotFound):
			writeJSON(w, http.StatusNotFound, api.APIResponse{Status: "error", Message: "database client not found"})
		case errors.Is(err, ErrForbidden):
			writeJSON(w, http.StatusForbidden, api.APIResponse{Status: "error", Message: "access denied"})
		case errors.Is(err, ErrInactive):
			writeJSON(w, http.StatusConflict, api.APIResponse{Status: "error", Message: "database client is inactive"})
		default:
			writeJSON(w, http.StatusInternalServerError, api.APIResponse{Status: "error", Message: err.Error()})
		}
		return
	}
	writeJSON(w, http.StatusOK, api.APIResponse{Status: "success", Message: "schema ingested", Data: schema})
}

func rejectUserMismatch(w http.ResponseWriter, r *http.Request, userID string) bool {
	if err := auth.MatchContextUserID(r.Context(), userID); err != nil {
		writeJSON(w, http.StatusForbidden, api.APIResponse{Status: "error", Message: "user_id does not match authenticated user"})
		return true
	}
	return false
}

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