// Package logger provides logging functionality
package logger

import (
	"errors"
	"fmt"
)

// Common logger error types
var (
	// ErrInvalidFormat indicates an invalid log format was specified
	ErrInvalidFormat = errors.New("invalid log format")

	// ErrInvalidLevel indicates an invalid log level was specified
	ErrInvalidLevel = errors.New("invalid log level")

	// ErrOutputFailed indicates a failure to set or write to the log output
	ErrOutputFailed = errors.New("failed to set or write to log output")

	// ErrFormatterFailed indicates a failure in the log formatter
	ErrFormatterFailed = errors.New("log formatter failed")

	// ErrInvalidConfig indicates missing or invalid logger configuration
	ErrInvalidConfig = errors.New("invalid logger configuration")
)

// Error represents a logger-specific error with detailed context
type Error struct {
	// Op is the operation that failed (e.g., "format", "level", "output")
	Op string

	// Err is the underlying error
	Err error

	// Details contains additional error context
	Details string

	// Setting indicates the configuration setting involved (if applicable)
	Setting string

	// Value indicates the invalid value (if applicable)
	Value string
}

// Error returns a string representation of the error
func (e *Error) Error() string {
	msg := fmt.Sprintf("logger %s failed", e.Op)
	if e.Setting != "" {
		msg = fmt.Sprintf("%s for setting %q", msg, e.Setting)
	}
	if e.Value != "" {
		msg = fmt.Sprintf("%s with value %q", msg, e.Value)
	}
	if e.Details != "" {
		msg = fmt.Sprintf("%s: %s", msg, e.Details)
	}
	if e.Err != nil {
		msg = fmt.Sprintf("%s: %v", msg, e.Err)
	}
	return msg
}

// Unwrap returns the underlying error
func (e *Error) Unwrap() error {
	return e.Err
}

// Is reports whether target matches this error
func (e *Error) Is(target error) bool {
	return errors.Is(e.Err, target)
}

// NewError creates a new logger error
func NewError(op string, err error, details string) *Error {
	return &Error{
		Op:      op,
		Err:     err,
		Details: details,
	}
}

// NewConfigError creates a new logger configuration error
func NewConfigError(op string, setting string, value string, err error, details string) *Error {
	return &Error{
		Op:      op,
		Setting: setting,
		Value:   value,
		Err:     err,
		Details: details,
	}
}

// IsConfigError returns true if the error indicates a configuration problem
func IsConfigError(err error) bool {
	var e *Error
	return errors.As(err, &e) && (errors.Is(e.Err, ErrInvalidFormat) ||
		errors.Is(e.Err, ErrInvalidLevel) ||
		errors.Is(e.Err, ErrInvalidConfig))
}

// IsOutputError returns true if the error indicates an output problem
func IsOutputError(err error) bool {
	var e *Error
	return errors.As(err, &e) && errors.Is(e.Err, ErrOutputFailed)
}