// Package errors provides a unified error handling strategy for the application.
// It extends the standard Go errors package with additional functionality for
// error wrapping, error types, and error logging.
package errors

import (
	"errors"
	"fmt"
	"runtime"
	"strings"

	"git.influ.su/artmares/digglestool/internal/pkg/logger"
)

// Standard errors that can be used throughout the application.
var (
	ErrNotFound       = errors.New("not found")
	ErrInvalidInput   = errors.New("invalid input")
	ErrInternal       = errors.New("internal error")
	ErrNotImplemented = errors.New("not implemented")
)

// Error represents an error with additional context.
type Error struct {
	// Original is the original error.
	Original error
	// Message is an additional message to provide context.
	Message string
	// File is the file where the error occurred.
	File string
	// Line is the line where the error occurred.
	Line int
}

// Error returns the error message.
func (e *Error) Error() string {
	if e.Original == nil {
		return e.Message
	}
	if e.Message == "" {
		return e.Original.Error()
	}
	return fmt.Sprintf("%s: %s", e.Message, e.Original.Error())
}

// Unwrap returns the original error.
func (e *Error) Unwrap() error {
	return e.Original
}

// New creates a new error with the given message.
func New(message string) error {
	return &Error{
		Message: message,
	}
}

// Wrap wraps an error with additional context.
// If err is nil, Wrap returns nil.
func Wrap(err error, message string) error {
	if err == nil {
		return nil
	}
	_, file, line, _ := runtime.Caller(1)
	file = trimFilePath(file)
	return &Error{
		Original: err,
		Message:  message,
		File:     file,
		Line:     line,
	}
}

// Wrapf wraps an error with a formatted message.
// If err is nil, Wrapf returns nil.
func Wrapf(err error, format string, args ...interface{}) error {
	if err == nil {
		return nil
	}
	_, file, line, _ := runtime.Caller(1)
	file = trimFilePath(file)
	return &Error{
		Original: err,
		Message:  fmt.Sprintf(format, args...),
		File:     file,
		Line:     line,
	}
}

// Is reports whether any error in err's chain matches target.
func Is(err, target error) bool {
	return errors.Is(err, target)
}

// As finds the first error in err's chain that matches target, and if so, sets
// target to that error value and returns true. Otherwise, it returns false.
func As(err error, target interface{}) bool {
	return errors.As(err, target)
}

// LogError logs an error with the appropriate log level and returns it.
// This is useful for logging an error while still returning it up the call stack.
func LogError(err error) error {
	if err == nil {
		return nil
	}

	var e *Error
	if errors.As(err, &e) {
		logger.Errorf("[%s:%d] %s", e.File, e.Line, err.Error())
	} else {
		_, file, line, _ := runtime.Caller(1)
		file = trimFilePath(file)
		logger.Errorf("[%s:%d] %s", file, line, err.Error())
	}

	return err
}

// LogWarn logs an error as a warning and returns it.
func LogWarn(err error) error {
	if err == nil {
		return nil
	}

	var e *Error
	if errors.As(err, &e) {
		logger.Warnf("[%s:%d] %s", e.File, e.Line, err.Error())
	} else {
		_, file, line, _ := runtime.Caller(1)
		file = trimFilePath(file)
		logger.Warnf("[%s:%d] %s", file, line, err.Error())
	}

	return err
}

// LogFatal logs an error as fatal and exits the program.
func LogFatal(err error) {
	if err == nil {
		return
	}

	var e *Error
	if errors.As(err, &e) {
		logger.Fatalf("[%s:%d] %s", e.File, e.Line, err.Error())
	} else {
		_, file, line, _ := runtime.Caller(1)
		file = trimFilePath(file)
		logger.Fatalf("[%s:%d] %s", file, line, err.Error())
	}
}

// trimFilePath trims the file path to make it more readable.
func trimFilePath(file string) string {
	// Find the last occurrence of "git.influ.su/artmares/digglestool"
	idx := strings.LastIndex(file, "git.influ.su\\artmares\\digglestool")
	if idx >= 0 {
		return file[idx+len("git.influ.su\\artmares\\digglestool"):]
	}
	return file
}