package app

import (
	"encoding/json"
	"fmt"
	"io"
	"net/http"
	"os"
	"strings"
	"time"
)

// ---------------------------------------------------------------------
// rollback / clear
// ---------------------------------------------------------------------

func handleRoutesClear(w http.ResponseWriter, r *http.Request) {
	if r.Method != http.MethodPost {
		http.Error(w, "method not allowed", http.StatusMethodNotAllowed)
		return
	}
	res := routesClear()
	writeJSON(w, http.StatusOK, res)
}

func handleRoutesCacheRestore(w http.ResponseWriter, r *http.Request) {
	if r.Method != http.MethodPost {
		http.Error(w, "method not allowed", http.StatusMethodNotAllowed)
		return
	}
	res := restoreRoutesFromCache()
	writeJSON(w, http.StatusOK, res)
}

func handleRoutesPrecheckDebug(w http.ResponseWriter, r *http.Request) {
	if r.Method != http.MethodPost {
		http.Error(w, "method not allowed", http.StatusMethodNotAllowed)
		return
	}

	var body struct {
		RunNow bool `json:"run_now"`
	}
	runNow := true
	if r.Body != nil {
		defer r.Body.Close()
		if err := json.NewDecoder(io.LimitReader(r.Body, 1<<20)).Decode(&body); err == nil {
			runNow = body.RunNow
		}
	}

	now := time.Now().UTC().Format(time.RFC3339)
	content := []byte("forced_at=" + now + "\n")
	if err := os.WriteFile(precheckForcePath, content, 0o644); err != nil {
		writeJSON(w, http.StatusOK, cmdResult{
			OK:      false,
			Message: fmt.Sprintf("precheck debug arm failed: %v", err),
		})
		return
	}
	appendTraceLineTo(traceLogPath, "routes", fmt.Sprintf("debug precheck armed: %s", precheckForcePath))

	if !runNow {
		writeJSON(w, http.StatusOK, cmdResult{
			OK:      true,
			Message: "precheck debug armed (run_now=false)",
		})
		return
	}

	// Run restart asynchronously: this endpoint is debug/helper and should return
	// immediately, otherwise GUI client can hit read-timeout while systemctl works.
	go func() {
		restartRes := runRoutesServiceAction("restart")
		if restartRes.OK {
			appendTraceLineTo(traceLogPath, "routes", "debug precheck: routes restart completed")
			return
		}
		appendTraceLineTo(traceLogPath, "routes", "debug precheck: routes restart failed: "+strings.TrimSpace(restartRes.Message))
	}()

	writeJSON(w, http.StatusOK, cmdResult{
		OK:      true,
		Message: "precheck debug armed + async routes restart requested",
	})
}