package handler

import (
	"fmt"
	"net/http"
)

/*
	Domain (First Digit)

		1xxx - Request/Input Errors

		2xxx - Authentication/Authorization

		3xxx - Business Logic/Validation

		4xxx - Data/Resource Errors

		5xxx - System/External Service Errors

	Category (Second Digit)

		x0xx - General/Generic errors in that domain

		x1xx - Format/Structure errors

		x2xx - Validation/Constraint errors

		x3xx - State/Workflow errors

		x4xx - Permission/Access errors

	Specific Error (Last Two Digits)

		xx00-xx99 - Specific error instances
*/

// Domains
const (
	DomainRequest = 1000
	DomainAuth    = 2000
	DomainData    = 4000
	DomainSystem  = 5000
)

const (
	CategoryGeneral    = 0
	CategoryFormat     = 100
	CategoryValidation = 200
	CategoryState      = 300
	CategoryPermission = 400
)

// Err code Domain + Category + Specific
const (
	CodeInvalidJSON      = DomainRequest + CategoryFormat + 1
	InvalidParamFormat   = DomainRequest + CategoryFormat + 0
	CodeValidationFailed = DomainRequest + CategoryValidation + 0
	CodeMissingRequired  = DomainRequest + CategoryValidation + 1
	CodeNotFound         = DomainData + CategoryPermission + 0
	CodeInternalError    = DomainSystem + CategoryGeneral + 0
)

var (
	ErrInvalidJSON     = APIError{Code: CodeInvalidJSON, Message: "Invalid JSON in request body"}
	ErrValidation      = APIError{Code: CodeValidationFailed, Message: "Validation failed"}
	ErrMissingRequired = APIError{Code: CodeMissingRequired, Message: "Required field is missing"}
	ErrNotFound        = APIError{Code: CodeNotFound, Message: "Resource not found"}
	ErrInternalServer  = APIError{Code: CodeInternalError, Message: "Internal server error"}
	ErrInvalidFormat   = APIError{Code: InvalidParamFormat, Message: "The given param doesn't match the format expectations"}
)

// Helper functions for common errors
func BadRequest(w http.ResponseWriter, err APIError, details string) {
	JSONError(w, err.Message, details, err.Code, http.StatusBadRequest)
}

func NotFound(w http.ResponseWriter, err APIError, details string) {
	JSONError(w, err.Message, details, err.Code, http.StatusNotFound)
}

func InternalError(w http.ResponseWriter, err error) {
	JSONError(w, ErrInternalServer.Message, err.Error(), ErrInternalServer.Code, http.StatusInternalServerError)
}

func RequiredFieldErr(field string) string {
	return (fmt.Sprintf("%s %s", field, required_field))
}