package app

import (
	"strings"
	"time"

	transportcfgpkg "selective-vpn-api/app/transportcfg"
)

func prepareSingBoxClientProfile(client TransportClient, checkBinary bool) transportBackendActionResult {
	if client.Kind != TransportClientSingBox {
		return transportBackendActionResult{
			OK:      true,
			Message: "singbox preflight skipped",
		}
	}

	singBoxProfilesMu.Lock()
	defer singBoxProfilesMu.Unlock()

	st := loadSingBoxProfilesState()
	idx := findSingBoxProfileIndexForClient(st, client.ID)
	if idx < 0 {
		return transportBackendActionResult{
			OK:       false,
			Code:     singBoxProfileCodeNotFound,
			Message:  "singbox profile not linked to client " + client.ID,
			ExitCode: -1,
		}
	}
	cur := st.Items[idx]
	now := time.Now().UTC().Format(time.RFC3339Nano)

	eval := evaluateSingBoxProfile(cur, checkBinary)
	cur.LastValidatedAt = now
	cur.UpdatedAt = now
	if !eval.Valid {
		cur.LastError = joinSingBoxIssueMessages(eval.Errors)
		st.Items[idx] = cur
		_ = saveSingBoxProfilesState(st)
		return transportBackendActionResult{
			OK:       false,
			Code:     singBoxProfileCodeValidationFailed,
			Message:  "profile preflight failed: " + strings.TrimSpace(cur.LastError),
			ExitCode: -1,
		}
	}

	renderPath, err := writeSingBoxRenderedConfig(cur.ID, eval.Config)
	if err != nil {
		cur.LastError = err.Error()
		st.Items[idx] = cur
		_ = saveSingBoxProfilesState(st)
		return transportBackendActionResult{
			OK:       false,
			Code:     singBoxProfileCodeRenderFailed,
			Message:  "profile preflight render failed: " + err.Error(),
			ExitCode: -1,
		}
	}

	configPath := transportSingBoxConfigPath(client)
	if strings.TrimSpace(configPath) == "" {
		configPath = defaultSingBoxAppliedConfigPath(cur.ID)
	}
	if err := transportcfgpkg.WriteJSONConfigFile(configPath, eval.Config); err != nil {
		cur.LastError = err.Error()
		st.Items[idx] = cur
		_ = saveSingBoxProfilesState(st)
		return transportBackendActionResult{
			OK:       false,
			Code:     singBoxProfileCodeApplyFailed,
			Message:  "profile preflight write failed: " + err.Error(),
			ExitCode: -1,
			Stdout:   renderPath,
		}
	}

	cur.LastError = ""
	st.Items[idx] = cur
	if err := saveSingBoxProfilesState(st); err != nil {
		return transportBackendActionResult{
			OK:       false,
			Code:     singBoxProfileCodeSaveFailed,
			Message:  "profile preflight save failed: " + err.Error(),
			ExitCode: -1,
			Stdout:   renderPath,
		}
	}

	return transportBackendActionResult{
		OK:       true,
		ExitCode: 0,
		Message:  "profile preflight ready: " + cur.ID,
		Stdout:   strings.TrimSpace(configPath),
		Stderr:   strings.TrimSpace(renderPath),
	}
}