// feedkit/config/params.go
package config

import "strings"

// ParamString returns the first non-empty string found for any of the provided keys.
// Values must actually be strings in the decoded config; other types are ignored.
//
// This keeps cfg.Params flexible (map[string]any) while letting callers stay type-safe.
func (cfg SourceConfig) ParamString(keys ...string) (string, bool) {
	if cfg.Params == nil {
		return "", false
	}
	for _, k := range keys {
		v, ok := cfg.Params[k]
		if !ok || v == nil {
			continue
		}
		s, ok := v.(string)
		if !ok {
			continue
		}
		s = strings.TrimSpace(s)
		if s == "" {
			continue
		}
		return s, true
	}
	return "", false
}

// ParamStringDefault returns ParamString(keys...) if present; otherwise it returns def.
// This is the “polite default” helper used by drivers for optional fields like user-agent.
func (cfg SourceConfig) ParamStringDefault(def string, keys ...string) string {
	if s, ok := cfg.ParamString(keys...); ok {
		return s
	}
	return strings.TrimSpace(def)
}

// ParamString returns the first non-empty string found for any of the provided keys
// in SinkConfig.Params. (Same rationale as SourceConfig.ParamString.)
func (cfg SinkConfig) ParamString(keys ...string) (string, bool) {
	if cfg.Params == nil {
		return "", false
	}
	for _, k := range keys {
		v, ok := cfg.Params[k]
		if !ok || v == nil {
			continue
		}
		s, ok := v.(string)
		if !ok {
			continue
		}
		s = strings.TrimSpace(s)
		if s == "" {
			continue
		}
		return s, true
	}
	return "", false
}

// ParamStringDefault returns ParamString(keys...) if present; otherwise it returns def.
// Symmetric helper for sink implementations.
func (cfg SinkConfig) ParamStringDefault(def string, keys ...string) string {
	if s, ok := cfg.ParamString(keys...); ok {
		return s
	}
	return strings.TrimSpace(def)
}