//go:build darwin

package update

import (
	"context"
	"fmt"
	"os"
	"os/exec"
	"path/filepath"
	"strconv"
	"strings"
)

// Apply downloads the new binary or .app.zip and schedules replacement + relaunch after exit.
func Apply(ctx context.Context, manifestURL string) (string, error) {
	p, err := prepareUpdate(ctx, manifestURL)
	if err != nil {
		return "", err
	}
	if p.Kind == AssetKindAppZip {
		return applyAppZip(p)
	}
	return applyBinary(p)
}

func applyBinary(p preparedUpdate) (string, error) {
	_ = os.Chmod(p.TmpPath, 0o755)
	dir := filepath.Dir(p.ExePath)
	scriptPath := filepath.Join(dir, "navis-update.sh")
	pid := os.Getpid()

	script := "#!/bin/bash\n" +
		"set -e\n" +
		"EXE=" + shellQuote(p.ExePath) + "\n" +
		"NEW=" + shellQuote(p.TmpPath) + "\n" +
		"PID=" + strconv.Itoa(pid) + "\n" +
		"while kill -0 \"$PID\" 2>/dev/null; do sleep 0.4; done\n" +
		"sleep 0.5\n" +
		"mv -f \"$NEW\" \"$EXE\"\n" +
		"chmod +x \"$EXE\"\n" +
		"rm -f " + shellQuote(scriptPath) + "\n" +
		"exec \"$EXE\"\n"

	if err := os.WriteFile(scriptPath, []byte(script), 0o755); err != nil {
		return "", err
	}
	cmd := exec.Command("/bin/bash", scriptPath)
	cmd.Dir = dir
	if err := cmd.Start(); err != nil {
		return "", fmt.Errorf("start updater: %w", err)
	}
	return p.Latest, nil
}

func applyAppZip(p preparedUpdate) (string, error) {
	if p.AppRoot == "" {
		return "", fmt.Errorf("update: empty app root")
	}
	parent := filepath.Dir(p.AppRoot)
	scriptPath := filepath.Join(parent, "navis-update-app.sh")
	pid := os.Getpid()
	identity := strings.TrimSpace(os.Getenv("NAVIS_CODESIGN_IDENTITY"))
	// Never re-sign with ad-hoc "-" after replacing a shipped .app — that strips
	// Developer ID / notarization. Only re-sign when a real identity is set.
	doSign := identity != "" && identity != "-"

	script := "#!/bin/bash\n" +
		"set -e\n" +
		"APP=" + shellQuote(p.AppRoot) + "\n" +
		"ZIP=" + shellQuote(p.TmpPath) + "\n" +
		"PID=" + strconv.Itoa(pid) + "\n" +
		"PARENT=$(dirname \"$APP\")\n" +
		"while kill -0 \"$PID\" 2>/dev/null; do sleep 0.4; done\n" +
		"sleep 0.5\n" +
		"TMP=$(mktemp -d \"$PARENT/.navis-update-XXXXXX\")\n" +
		"unzip -q \"$ZIP\" -d \"$TMP\"\n" +
		"NEW=$(find \"$TMP\" -maxdepth 3 -name 'Navis.app' -type d | head -n 1)\n" +
		"if [ -z \"$NEW\" ] || [ ! -d \"$NEW\" ]; then echo 'Navis.app missing in zip' >&2; exit 1; fi\n" +
		"rm -rf \"$APP.bak\"\n" +
		"mv \"$APP\" \"$APP.bak\"\n" +
		"mv \"$NEW\" \"$APP\"\n"
	if doSign {
		script += "ID=" + shellQuote(identity) + "\n" +
			"if command -v codesign >/dev/null 2>&1; then\n" +
			"  codesign -s \"$ID\" --force --deep --options runtime --timestamp \"$APP\"\n" +
			"  codesign --verify --deep --strict \"$APP\"\n" +
			"fi\n"
	}
	script += "xattr -cr \"$APP\" 2>/dev/null || true\n" +
		"rm -rf \"$APP.bak\" \"$TMP\" \"$ZIP\" " + shellQuote(scriptPath) + "\n" +
		"open \"$APP\"\n"

	if err := os.WriteFile(scriptPath, []byte(script), 0o755); err != nil {
		return "", err
	}
	cmd := exec.Command("/bin/bash", scriptPath)
	cmd.Dir = parent
	if err := cmd.Start(); err != nil {
		return "", fmt.Errorf("start app updater: %w", err)
	}
	return p.Latest, nil
}

func shellQuote(s string) string {
	return "'" + strings.ReplaceAll(s, "'", `'\''`) + "'"
}

// CleanupStaleDownloads removes leftover update temps from failed/old runs.
func CleanupStaleDownloads() {
	exe, err := os.Executable()
	if err != nil {
		return
	}
	exe, _ = filepath.Abs(exe)
	_ = os.Remove(exe + ".new")
	dir := filepath.Dir(exe)
	_ = os.Remove(filepath.Join(dir, ".navis-update-download"))
	_ = os.Remove(filepath.Join(dir, ".navis-update-app.zip"))
	if root, ok := AppBundleRoot(exe); ok {
		parent := filepath.Dir(root)
		_ = os.Remove(filepath.Join(parent, ".navis-update-app.zip"))
		_ = os.Remove(filepath.Join(parent, "navis-update-app.sh"))
		_ = os.Remove(filepath.Join(parent, "navis-update.sh"))
	}
}