#include "log.h"
#include "config.h"
#include "strings.h"

inline static
int is_kv_seperator(int ch){
	return (ch == '=') || (ch == ':');
}

Config* Config::load(const char *filename){
	FILE *fp = NULL;
	int lineno = 0;

	if(strcmp(filename, "stdout") == 0){
		fp = stdin;
	}else{
		fp = fopen(filename, "r");
		if(!fp){
			log_error("error opening file '%s': %s", filename, strerror(errno));
			return NULL;
		}
	}

	Config *root = new Config("root", "");
	Config *cfg = root;
	int last_indent = 0;
	char buf[CONFIG_MAX_LINE];
	while(fgets(buf, sizeof(buf), fp)){
		lineno++;

		buf[strlen(buf) - 1] = '\0'; /* 去除 '\n' */
		if(is_empty_str(buf)){
			continue;
		}

		/* 有效行以 \t* 开头 */
		int indent = strspn(buf, "\t");
		char *key = buf + indent;

		if(*key == '#'){
			cfg->add("#", key + 1, lineno);
			continue;
		}
		if(indent <= last_indent){
			for(int i = indent; i <= last_indent; i++){
				/* 第一个配置时, 此条件为真 */
				if(cfg != root){
					cfg = cfg->parent;
				}
			}
		}else if(indent > last_indent + 1){
			log_error("invalid indent line(%d)", lineno);
			goto err;
		}
		
		if(isspace(*key)){
			log_error("invalid line(%d): unexpected whitespace char '%c'", lineno, *key);
			goto err;
		}

		char *val = key;
		/* 跳过键名 */
		while(*val && !is_kv_seperator(*val)){
			val++;
		}
		if(*val == '\0'){
			log_error("invalid line(%d): %s, expecting ':' or '='", lineno, *val);
			goto err;
		}else if(!is_kv_seperator(*val)){
			log_error("invalid line(%d): unexpected char '%c', expecting ':' or '='", lineno, *val);
			goto err;
		}
		*val++ = '\0';

		/* key 或者 value 的前后空白字符会被过滤 */
		key = trim(key);
		val = trim(val);

		cfg = cfg->add(key, val, lineno);
		if(cfg == NULL){
			goto err;
		}

		last_indent = indent;
	}
	if(ferror(fp)){
		log_error("error while reading file %s", filename);
		goto err;
	}
	fclose(fp);
	return root;
err:
	if(root){
		delete root;
	}
	if(fp && fp != stdin){
		fclose(fp);
	}
	return NULL;
}

Config::~Config(){
	//log_trace("%*sfree %s(%d)", depth*4, "", this->key.c_str(), this->children.size());
	for(int i = 0; i < (int)children.size(); i++){
		delete children[i];
	}
}

Config* Config::add(const char *key, const char *val, int lineno){
	if(key[0] != '#' && this->find_child(key)){
		//log_error("line: %d, duplicated '%s'", lineno, key);
		//return NULL;
	}

	Config *child = new Config(key, val);
	child->parent = this;
	child->depth = this->depth + 1;
	children.push_back(child);

	log_trace("%*s'%s' : '%s'", depth*4, "", this->key.c_str(), key);
	return child;
}

const Config* Config::find_child(const char *key) const{
	for(int i = 0; i < (int)children.size(); i++){
		if(children[i]->key == key){
			return children[i];
		}
	}
	return NULL;
}

const Config* Config::get(const char *key) const{
	char path[CONFIG_MAX_LINE];

	const Config *conf = this;
	strcpy(path, key);

	char *f, *fs; /* field, field seperator */
	f = fs = path;
	while(conf){
		switch(*fs++){
			case '.':
			case '/':
				*(fs - 1) = '\0';
				conf = conf->find_child(f);
				f = fs;
				break;
			case '\0':
				conf = conf->find_child(f);
				return conf;
			default:
				break;
		}
	}
	return conf;
}

int Config::num() const{
	return atoi(this->val.c_str());
}

const char* Config::str() const{
	return this->val.c_str();
}

int Config::get_num(const char *key) const{
	const Config *c = this->get(key);
	if(!c){
		return 0;
	}
	return c->num();
}

const char* Config::get_str(const char *key) const{
	const Config *c = this->get(key);
	if(!c){
		return "";
	}
	return c->str();
}

int Config::save(FILE *fp) const{
	for(int i = 0; i < (int)children.size(); i++){
		Config *c = children[i];
		for(int j=0; j<this->depth; j++){
			fputc('\t', fp);
		}

		if(c->is_comment()){
			fprintf(fp, "#%s\n", c->val.c_str());
		}else{
			fprintf(fp, "%s: %s\n", c->key.c_str(), c->val.c_str());
		}
		c->save(fp);
	}
	return 0;
}

int Config::save(const char *filename) const{
	FILE *fp;

	if(strcmp(filename, "stdout") == 0){
		fp = stdout;
	}else if(strcmp(filename, "stderr") == 0){
		fp = stderr;
	}else{
		fp = fopen(filename, "w");
		if(!fp){
			log_error("error opening file '%s': %s", filename, strerror(errno));
			return -1;
		}
	}
	this->save(fp);
	if(fp && fp != stdout && fp != stderr){
		fclose(fp);
	}
	return 0;
}