use directories::ProjectDirs;
use serde::{Deserialize, Serialize};
use std::fs;
use std::io::Write;
use std::path::PathBuf;

use crate::error::{Error, Result};
use crate::utils;

#[derive(Deserialize, Serialize, Debug, Clone)]
pub struct Config {
    pub api_key: Option<String>,
    pub limit: u16,
    pub lucky: bool,
    pub sites: Vec<String>,
}

// TODO make a friender config file, like the colors.toml below
impl Default for Config {
    fn default() -> Self {
        Config {
            api_key: None,
            limit: 20,
            lucky: true,
            sites: vec![String::from("stackoverflow")],
        }
    }
}

/// Get user config (writes default if none found)
pub fn user_config() -> Result<Config> {
    let project = project_dir()?;
    let dir = project.config_dir();
    fs::create_dir_all(&dir)?;
    let filename = config_file_name()?;
    match utils::open_file(&filename)? {
        None => {
            let def = Config::default();
            write_config(&def)?;
            Ok(def)
        }
        Some(file) => serde_yaml::from_reader(file).map_err(|_| Error::MalformedFile(filename)),
    }
}

pub fn set_api_key(key: String) -> Result<()> {
    let mut cfg = user_config()?;
    cfg.api_key = Some(key);
    write_config(&cfg)
}

/// Get project directory
pub fn project_dir() -> Result<ProjectDirs> {
    ProjectDirs::from("io", "Sam Tay", "so").ok_or_else(|| Error::ProjectDir)
}

pub fn theme_file_name() -> Result<PathBuf> {
    let name = project_dir()?.config_dir().join("colors.toml");
    if !name.as_path().exists() {
        let mut file = utils::create_file(&name)?;
        file.write_all(DEFAULT_COLORS_TOML.as_bytes())?;
    }
    Ok(name)
}

fn write_config(config: &Config) -> Result<()> {
    let filename = config_file_name()?;
    let file = utils::create_file(&filename)?;
    Ok(serde_yaml::to_writer(file, config)?)
}

// TODO consider switching to .toml to be consistent with colors.toml
fn config_file_name() -> Result<PathBuf> {
    Ok(project_dir()?.config_dir().join("config.yml"))
}

static DEFAULT_COLORS_TOML: &str = r##"
# Every field in a theme file is optional.

shadow = false
borders = "outset" # Alternatives are "none" and "simple"

# Base colors are
# red, green, blue, cyan, magenta, yellow, white and black.
#
# There are 3 ways to select a color:
# - The 16 base colors are selected by name:
#       "blue", "light red", "magenta", ...
# - Low-resolution colors use 3 characters, each <= 5:
#       "541", "003", ...
# - Full-resolution colors start with '#' and can be 3 or 6 hex digits:
#       "#1A6", "#123456", ...
[colors]
background = "default"

# If the terminal doesn't support custom color (like the linux TTY),
# non-base colors will be skipped.
shadow     = []
view       = "default"

# An array with a single value has the same effect as a simple value.
primary   = ["default"]
secondary = "cyan" # secondary style is used for code hightlighting
tertiary  = "green"

# Hex values can use lower or uppercase.
# (base color MUST be lowercase)
# If the value is an array, the first valid
# and supported color will be used.
title_primary   = ["BLUE", "red"] # `BLUE` will be skipped.
title_secondary = "yellow"

# Lower precision values can use only 3 digits.
highlight          = "yellow"
highlight_inactive = "light yellow"
"##;