package transportcfg

import (
	"os"
	"strings"
	"time"
)

type RunCommandTimeoutFunc func(timeout time.Duration, name string, args ...string) (stdout string, stderr string, exitCode int, err error)

func ValidateRenderedConfigWithBinary(
	config map[string]any,
	run RunCommandTimeoutFunc,
	timeout time.Duration,
	binaryCandidates ...string,
) *SingBoxIssue {
	if len(config) == 0 {
		return &SingBoxIssue{
			Field:    "config",
			Severity: "error",
			Code:     "SINGBOX_RENDER_EMPTY",
			Message:  "rendered config is empty",
		}
	}
	bin, _ := FirstExistingBinaryCandidate(binaryCandidates...)
	if strings.TrimSpace(bin) == "" {
		return &SingBoxIssue{
			Field:    "binary",
			Severity: "warning",
			Code:     "SINGBOX_BINARY_MISSING",
			Message:  "sing-box binary not found; binary check skipped",
		}
	}
	if run == nil {
		return &SingBoxIssue{
			Field:    "binary",
			Severity: "warning",
			Code:     "SINGBOX_CHECK_RUNNER_MISSING",
			Message:  "command runner is not configured; binary check skipped",
		}
	}

	tmp, err := os.CreateTemp("", "svpn-singbox-check-*.json")
	if err != nil {
		return &SingBoxIssue{
			Field:    "binary",
			Severity: "warning",
			Code:     "SINGBOX_CHECK_TEMPFILE_FAILED",
			Message:  err.Error(),
		}
	}
	tmpPath := tmp.Name()
	_ = tmp.Close()
	defer os.Remove(tmpPath)

	if err := WriteJSONConfigFile(tmpPath, config); err != nil {
		return &SingBoxIssue{
			Field:    "binary",
			Severity: "warning",
			Code:     "SINGBOX_CHECK_TEMPFILE_FAILED",
			Message:  err.Error(),
		}
	}

	stdout, _, code, runErr := run(timeout, bin, "check", "-c", tmpPath)
	if runErr == nil && code == 0 {
		return nil
	}
	msg := strings.TrimSpace(stdout)
	if msg == "" && runErr != nil {
		msg = runErr.Error()
	}
	if msg == "" {
		msg = "sing-box check failed"
	}
	return &SingBoxIssue{
		Field:    "config",
		Severity: "error",
		Code:     "SINGBOX_CHECK_FAILED",
		Message:  msg,
	}
}