package updates

import (
	"encoding/json"
	"strings"
)

// winUpdate is one row of the Windows Update searcher's output, in the shape
// searchScript emits it.
type winUpdate struct {
	Title string `json:"title"`
	KB    string `json:"kb"`
}

// parseUpdateSearch reads the searcher's JSON.
//
// It carries no build tag on purpose: this is the half of the Windows update
// path that can be tested on a development machine, and the agent module has no
// Windows CI.
func parseUpdateSearch(jsonText string) ([]PackageUpdate, error) {
	s := strings.TrimSpace(jsonText)
	if s == "" || s == "null" {
		return nil, nil
	}

	var rows []winUpdate
	if err := json.Unmarshal([]byte(s), &rows); err != nil {
		// ConvertTo-Json renders a one-element array as a bare object.
		var one winUpdate
		if err2 := json.Unmarshal([]byte(s), &one); err2 != nil {
			return nil, err
		}
		rows = []winUpdate{one}
	}

	out := make([]PackageUpdate, 0, len(rows))
	for _, r := range rows {
		u := PackageUpdate{Name: r.Title}
		if kb := strings.TrimSpace(r.KB); kb != "" {
			if !strings.HasPrefix(strings.ToUpper(kb), "KB") {
				kb = "KB" + kb
			}
			u.NewVersion = kb
		}
		out = append(out, u)
	}
	return out, nil
}