package whois

import "strings"

// LookupStrategy provides per-TLD mode mapping used when Lookup mode is auto.
type LookupStrategy struct {
	DefaultMode LookupMode
	TLDModes    map[string]LookupMode
}

func defaultLookupStrategy() LookupStrategy {
	return LookupStrategy{
		DefaultMode: LookupModeAutoPreferRDAP,
		TLDModes:    map[string]LookupMode{},
	}
}

func cloneLookupStrategy(in LookupStrategy) LookupStrategy {
	out := LookupStrategy{
		DefaultMode: in.DefaultMode,
		TLDModes:    map[string]LookupMode{},
	}
	for k, v := range in.TLDModes {
		tld := normalizeRDAPTLD(k)
		if tld == "" {
			continue
		}
		out.TLDModes[tld] = normalizeLookupMode(v)
	}
	return out
}

func (s LookupStrategy) modeForDomain(domain string, fallback LookupMode) LookupMode {
	tld := normalizeRDAPTLD(getExtension(domain))
	if tld != "" {
		if m, ok := s.TLDModes[tld]; ok {
			return normalizeLookupMode(m)
		}
	}
	if strings.TrimSpace(string(s.DefaultMode)) != "" {
		return normalizeLookupMode(s.DefaultMode)
	}
	return normalizeLookupMode(fallback)
}

func (o LookupOptions) resolveMode(domain string) LookupMode {
	mode := normalizeLookupMode(o.Mode)
	if mode != LookupModeAutoPreferRDAP {
		return mode
	}
	return o.Strategy.modeForDomain(domain, mode)
}

// WithLookupStrategy sets full lookup strategy.
func WithLookupStrategy(strategy LookupStrategy) LookupOpt {
	return func(o *LookupOptions) {
		o.Strategy = cloneLookupStrategy(strategy)
	}
}

// WithLookupTLDStrategy sets one tld-specific lookup mode used under auto mode.
func WithLookupTLDStrategy(tld string, mode LookupMode) LookupOpt {
	return func(o *LookupOptions) {
		if o.Strategy.TLDModes == nil {
			o.Strategy.TLDModes = map[string]LookupMode{}
		}
		key := normalizeRDAPTLD(tld)
		if key == "" {
			return
		}
		o.Strategy.TLDModes[key] = normalizeLookupMode(mode)
	}
}

// WithLookupTLDStrategies sets multiple tld-specific lookup modes used under auto mode.
func WithLookupTLDStrategies(m map[string]LookupMode) LookupOpt {
	return func(o *LookupOptions) {
		for tld, mode := range m {
			WithLookupTLDStrategy(tld, mode)(o)
		}
	}
}

// WithLookupStrategyDefaultMode sets default strategy mode used under auto mode.
func WithLookupStrategyDefaultMode(mode LookupMode) LookupOpt {
	return func(o *LookupOptions) {
		o.Strategy.DefaultMode = normalizeLookupMode(mode)
	}
}