use json;
use serde_json;

use std::io::prelude::*;
use std::fs::File;
use std::path::PathBuf;

use actions::*;
use knowledge::*;

const STATE_FILE: &'static str = "state.json";

const COMMAND_FILE: &'static str = "command.txt";
const PLACE_FILE: &'static str = "place.txt";

const KNOWLEDGE_FILE: &'static str = "knowledge-state.json";


pub fn read_file(working_dir: &PathBuf) -> Result<json::JsonValue, String> {
    let state_path = working_dir.join(STATE_FILE);
    let mut file = File::open(state_path.as_path()).map_err(|e| e.to_string())?;
    let mut content = String::new();
    file.read_to_string(&mut content).map_err(|e| e.to_string())?;
    json::parse(content.as_ref()).map_err(|e| e.to_string())
}

pub fn write_action(working_dir: &PathBuf, is_place_phase: bool, action: Action) -> Result<(), String> {
    let filename = if is_place_phase {
        PLACE_FILE
    }
    else {
        COMMAND_FILE
    };
    
    let full_filename = working_dir.join(filename);
    let mut file = File::create(full_filename.as_path()).map_err(|e| e.to_string())?;
    write!(file, "{}", action).map_err(|e| e.to_string())?;

    println!("Making move: {}", action);
    
    Ok(())
}

pub fn read_knowledge() -> Result<Knowledge, String> {
    let mut file = File::open(KNOWLEDGE_FILE).map_err(|e| e.to_string())?;
    let mut content = String::new();
    file.read_to_string(&mut content).map_err(|e| e.to_string())?; 
    serde_json::from_str(content.as_ref()).map_err(|e| e.to_string())
}

pub fn write_knowledge(knowledge: &Knowledge) -> Result<(), String> {
    let json = serde_json::to_string(knowledge).map_err(|e| e.to_string())?;
    let mut file = File::create(KNOWLEDGE_FILE).map_err(|e| e.to_string())?;
    write!(file, "{}", json).map_err(|e| e.to_string())?;

    Ok(())
}