package com.github.yin.flags;

import org.slf4j.Logger;

import org.slf4j.LoggerFactory;

import javax.annotation.Nonnull;

import java.util.Collection;

import java.util.Collections;

import java.util.List;

import java.util.Map;

/**

* Parses a {@link Map} of flags and {@link String} values.

*/

public class MapParser implements Parser<Map<String, String>> {

private static final Logger log = LoggerFactory.getLogger(GflagsParser.class);

private final FlagIndex<FlagMetadata> flags;

public MapParser(@Nonnull FlagIndex<FlagMetadata> flags) {

this.flags = flags;

}

@Override

public List<String> parse(Map<String, String> args) {

for (Map.Entry<String, String> arg : args.entrySet()) {

next(arg.getKey(), arg.getValue());

}

return Collections.EMPTY_LIST;

}

protected void next(String key, String value) {

Collection<FlagMetadata> flagsByName = flags.byName().get(key);

if (flagsByName.size() == 1) {

flagsByName.iterator().next().flag().parse(value);

} else if (flagsByName.isEmpty()) {

errorUnknownFlag(key);

} else {

errorAmbigousFlag(key, flagsByName);

}

}

protected void errorUnknownFlag(String flag) {

log.error("Unknown flag: {}", flag);

}

protected void errorAmbigousFlag(String flag, Collection<FlagMetadata> flagsByName) {

log.error("Flag {} resolves in multiple classes: {}", flag,

flagsByName.stream().map(meta -> meta.flagID()).toArray());

}

}