package api

import (
	"net/http"
	"strconv"
)

// asString coerces an arbitrary JSON value to a string.
func asString(v any) string {
	switch t := v.(type) {
	case string:
		return t
	case nil:
		return ""
	default:
		return ""
	}
}

// asInt coerces a JSON number/string to an int.
func asInt(v any) int {
	switch t := v.(type) {
	case float64:
		return int(t)
	case int:
		return t
	case string:
		if n, err := strconv.Atoi(t); err == nil {
			return n
		}
	}
	return 0
}

// asStringSlice coerces a JSON array (or single string) to []string.
func asStringSlice(v any) []string {
	switch t := v.(type) {
	case []any:
		out := make([]string, 0, len(t))
		for _, e := range t {
			if s, ok := e.(string); ok {
				out = append(out, s)
			}
		}
		return out
	case []string:
		return t
	case string:
		if t == "" {
			return nil
		}
		return []string{t}
	}
	return nil
}

// queryInt parses a query parameter as an int, falling back to def.
func queryInt(r *http.Request, key string, def int) int {
	if v := r.URL.Query().Get(key); v != "" {
		if n, err := strconv.Atoi(v); err == nil {
			return n
		}
	}
	return def
}