package clawdforge

import (
	"errors"
	"fmt"
)

// ErrAuth is the sentinel returned for 401/403 responses from clawdforge.
// Use errors.Is(err, ErrAuth) to detect auth failures.
var ErrAuth = errors.New("clawdforge: authentication failed")

// APIError carries a non-2xx response from clawdforge — status code plus
// the response body (truncated to a sane size). It is returned for any
// HTTP status >= 400 that isn't an auth failure.
type APIError struct {
	StatusCode int
	// Body is the raw response body (truncated). Useful for debugging.
	Body string
	// Message is a short human-readable summary derived from the body
	// when the body is JSON of the form {"error": "..."} or {"detail": "..."}.
	Message string
}

func (e *APIError) Error() string {
	if e.Message != "" {
		return fmt.Sprintf("clawdforge: HTTP %d: %s", e.StatusCode, e.Message)
	}
	return fmt.Sprintf("clawdforge: HTTP %d: %s", e.StatusCode, e.Body)
}

// TransportError wraps a low-level network/transport failure (DNS, connect
// refused, TLS, EOF, context cancellation, etc.). The wrapped error is
// available via errors.Unwrap.
type TransportError struct {
	Op  string
	Err error
}

func (e *TransportError) Error() string {
	return fmt.Sprintf("clawdforge: transport %s: %v", e.Op, e.Err)
}

func (e *TransportError) Unwrap() error { return e.Err }

// RunFailure represents a 502 response from /run — clawdforge accepted the
// request but `claude -p` failed (timeout, non-zero exit, etc.). The body
// fields mirror the server's failure shape.
//
// RunFailure satisfies APIError-like semantics by also embedding the status
// code via the underlying APIError, but it's a distinct type so callers can
// branch on errors.As(err, &cf.RunFailure{}).
type RunFailure struct {
	StatusCode int
	Err        string `json:"error"`
	Stderr     string `json:"stderr"`
	DurationMS int    `json:"duration_ms"`
	StopReason string `json:"stop_reason"`
}

func (e *RunFailure) Error() string {
	return fmt.Sprintf("clawdforge: run failed (stop_reason=%s): %s", e.StopReason, e.Err)
}