extern crate yaml_rust;
use self::yaml_rust::YamlLoader;

use std::collections::HashMap;
use std::fs::File;
use std::io::prelude::*;

pub struct SectionConfig {
    pub pattern: String,
    pub groups: Vec<String>,
}

pub struct Config {
    pub sections: HashMap<String, SectionConfig>,
}

impl Config {
    pub fn from_file(p: &str, expected: Vec<&'static str>) -> Self {
        let mut f = File::open(p).unwrap();
        let mut buf = String::new();
        f.read_to_string(&mut buf).unwrap();
        let docs = YamlLoader::load_from_str(&buf).unwrap();

        let doc = &docs[0];

        let mut sections: HashMap<String, SectionConfig> = HashMap::new();
        for (name, entry) in doc["sections"].as_hash().unwrap() {
            sections.insert(name.as_str().unwrap().into(),
                            SectionConfig {
                                pattern: entry["pattern"].as_str().unwrap().into(),
                                groups: entry["groups"]
                                    .as_vec()
                                    .unwrap()
                                    .into_iter()
                                    .map(|v| v.as_str().unwrap().into())
                                    .collect(),
                            });
        }


        for ex in &expected {
            if !sections.contains_key(&ex.to_string()) {
                panic!("config: section '{}' not found", ex);
            }
        }

        {
            let traits = &sections["traits"];
            if !traits.groups.contains(&"indexed_raw".to_string()) {
                panic!("config: no group 'indexed_raw' found in section 'traits'");
            }
            if !traits.groups.contains(&"official_raw".to_string()) {
                panic!("config: no group 'official_raw' found in section 'traits'");
            }
            let tags = &sections["tags"];
            if !tags.groups.contains(&"tags_raw".to_string()) {
                panic!("config: no group 'tags_raw' found in section 'tags'");
            }
        }

        Config { sections: sections }
    }
}