#![cfg(test)]

use std::fs::File;
use std::io::{BufReader, Write};
use std::path::Path;

use bytelines::ByteLines;
use itertools;

use crate::ansi;
use crate::cli;
use crate::config;
use crate::delta::delta;
use crate::git_config::GitConfig;

pub fn make_options_from_args_and_git_config(
    args: &[&str],
    git_config_contents: Option<&[u8]>,
    git_config_path: Option<&str>,
) -> cli::Opt {
    _make_options_from_args_and_git_config(args, git_config_contents, git_config_path, false)
}

pub fn make_options_from_args_and_git_config_honoring_env_var(
    args: &[&str],
    git_config_contents: Option<&[u8]>,
    git_config_path: Option<&str>,
) -> cli::Opt {
    _make_options_from_args_and_git_config(args, git_config_contents, git_config_path, true)
}

fn _make_options_from_args_and_git_config(
    args: &[&str],
    git_config_contents: Option<&[u8]>,
    git_config_path: Option<&str>,
    honor_env_var: bool,
) -> cli::Opt {
    let mut args: Vec<&str> = itertools::chain(&["/dev/null", "/dev/null"], args)
        .map(|s| *s)
        .collect();
    let mut git_config = match (git_config_contents, git_config_path) {
        (Some(contents), Some(path)) => Some(make_git_config(contents, path, honor_env_var)),
        _ => {
            args.push("--no-gitconfig");
            None
        }
    };
    cli::Opt::from_iter_and_git_config(args, &mut git_config)
}

pub fn make_options_from_args(args: &[&str]) -> cli::Opt {
    make_options_from_args_and_git_config(args, None, None)
}

#[allow(dead_code)]
pub fn make_config_from_args_and_git_config(
    args: &[&str],
    git_config_contents: Option<&[u8]>,
    git_config_path: Option<&str>,
) -> config::Config {
    config::Config::from(make_options_from_args_and_git_config(
        args,
        git_config_contents,
        git_config_path,
    ))
}

pub fn make_config_from_args(args: &[&str]) -> config::Config {
    config::Config::from(make_options_from_args(args))
}

pub fn make_git_config(contents: &[u8], path: &str, honor_env_var: bool) -> GitConfig {
    let path = Path::new(path);
    let mut file = File::create(path).unwrap();
    file.write_all(contents).unwrap();
    GitConfig::from_path(&path, honor_env_var)
}

pub fn get_line_of_code_from_delta(
    input: &str,
    line_number: usize,
    expected_text: &str,
    config: &config::Config,
) -> String {
    let output = run_delta(&input, config);
    let line_of_code = output.lines().nth(line_number).unwrap();
    assert!(ansi::strip_ansi_codes(line_of_code) == expected_text);
    line_of_code.to_string()
}

pub fn run_delta(input: &str, config: &config::Config) -> String {
    let mut writer: Vec<u8> = Vec::new();

    delta(
        ByteLines::new(BufReader::new(input.as_bytes())),
        &mut writer,
        &config,
    )
    .unwrap();
    String::from_utf8(writer).unwrap()
}