use crate::color::Color;
use std::convert::TryFrom;
use std::{env, ffi::OsString};

#[derive(Clone, Debug)]
pub struct Config {
	pub auto_select_next: bool,
	pub break_color: Color,
	pub comment_char: String,
	pub diff_add_color: Color,
	pub diff_change_color: Color,
	pub diff_remove_color: Color,
	pub drop_color: Color,
	pub edit_color: Color,
	pub editor: OsString,
	pub error_color: Color,
	pub exec_color: Color,
	pub fixup_color: Color,
	pub foreground_color: Color,
	pub indicator_color: Color,
	pub input_abort: String,
	pub input_action_break: String,
	pub input_action_drop: String,
	pub input_action_edit: String,
	pub input_action_fixup: String,
	pub input_action_pick: String,
	pub input_action_reword: String,
	pub input_action_squash: String,
	pub input_confirm_no: String,
	pub input_confirm_yes: String,
	pub input_edit: String,
	pub input_force_abort: String,
	pub input_force_rebase: String,
	pub input_help: String,
	pub input_move_down: String,
	pub input_move_selection_down: String,
	pub input_move_selection_up: String,
	pub input_move_up: String,
	pub input_open_in_external_editor: String,
	pub input_rebase: String,
	pub input_show_commit: String,
	pub input_toggle_visual_mode: String,
	pub pick_color: Color,
	pub reword_color: Color,
	pub squash_color: Color,
	pub vertical_spacing_character: String,
}

fn get_input(config: &git2::Config, name: &str, default: &str) -> Result<String, String> {
	let value = get_string(config, name, default)?;

	match value.to_lowercase().as_ref() {
		"left" => Ok(String::from("Left")),
		"right" => Ok(String::from("Right")),
		"down" => Ok(String::from("Down")),
		"up" => Ok(String::from("Up")),
		_ => {
			if value.len() > 1 {
				return Err(format!(
					"Error reading git config: {} must contain only one character",
					name
				));
			}
			Ok(value)
		},
	}
}

fn get_string(config: &git2::Config, name: &str, default: &str) -> Result<String, String> {
	match config.get_string(name) {
		Ok(v) => Ok(v),
		Err(ref e) if e.code() == git2::ErrorCode::NotFound => Ok(String::from(default)),
		Err(e) => Err(format!("Error reading git config: {}", e)),
	}
}

fn get_os_string(config: &git2::Config, name: &str, default: OsString) -> Result<OsString, String> {
	match config.get_string(name) {
		Ok(v) => Ok(OsString::from(v)),
		Err(ref e) if e.code() == git2::ErrorCode::NotFound => Ok(default),
		Err(e) => Err(format!("Error reading git config: {}", e)),
	}
}

fn get_bool(config: &git2::Config, name: &str, default: bool) -> Result<bool, String> {
	match config.get_bool(name) {
		Ok(v) => Ok(v),
		Err(ref e) if e.code() == git2::ErrorCode::NotFound => Ok(default),
		Err(e) => Err(format!("Error reading git config: {}", e)),
	}
}

fn get_color(config: &git2::Config, name: &str, default_color: Color) -> Result<Color, String> {
	match config.get_string(name) {
		Ok(v) => Color::try_from(v.to_lowercase().as_str()),
		Err(ref e) if e.code() == git2::ErrorCode::NotFound => Ok(default_color),
		Err(e) => Err(format!("Error reading git config: {}", e)),
	}
}

fn editor_from_env() -> OsString {
	env::var_os("VISUAL")
		.or_else(|| env::var_os("EDITOR"))
		.unwrap_or_else(|| OsString::from("vi"))
}

fn open_git_config() -> Result<git2::Config, String> {
	match git2::Repository::open_from_env() {
		Ok(f) => {
			match f.config() {
				Ok(c) => Ok(c),
				Err(e) => Err(format!("Error reading git config: {}", e)),
			}
		},
		Err(e) => Err(format!("Error reading git config: {}", e)),
	}
}

impl Config {
	pub fn new() -> Result<Self, String> {
		let git_config = open_git_config()?;
		Ok(Config {
			auto_select_next: get_bool(&git_config, "interactive-rebase-tool.autoSelectNext", false)?,
			break_color: get_color(&git_config, "interactive-rebase-tool.breakColor", Color::White)?,
			comment_char: get_string(&git_config, "core.commentChar", "#")?,
			diff_add_color: get_color(&git_config, "interactive-rebase-tool.diffAddColor", Color::Green)?,
			diff_change_color: get_color(&git_config, "interactive-rebase-tool.diffChangeColor", Color::Yellow)?,
			diff_remove_color: get_color(&git_config, "interactive-rebase-tool.diffRemoveColor", Color::Red)?,
			drop_color: get_color(&git_config, "interactive-rebase-tool.dropColor", Color::Red)?,
			edit_color: get_color(&git_config, "interactive-rebase-tool.editColor", Color::Blue)?,
			editor: get_os_string(&git_config, "core.editor", editor_from_env())?,
			error_color: get_color(&git_config, "interactive-rebase-tool.errorColor", Color::Red)?,
			exec_color: get_color(&git_config, "interactive-rebase-tool.execColor", Color::White)?,
			fixup_color: get_color(&git_config, "interactive-rebase-tool.fixupColor", Color::Magenta)?,
			foreground_color: get_color(&git_config, "interactive-rebase-tool.foregroundColor", Color::White)?,
			indicator_color: get_color(&git_config, "interactive-rebase-tool.indicatorColor", Color::Cyan)?,
			input_abort: get_input(&git_config, "interactive-rebase-tool.inputAbort", "q")?,
			input_action_break: get_input(&git_config, "interactive-rebase-tool.inputActionBreak", "b")?,
			input_action_drop: get_input(&git_config, "interactive-rebase-tool.inputActionDrop", "d")?,
			input_action_edit: get_input(&git_config, "interactive-rebase-tool.inputActionEdit", "e")?,
			input_action_fixup: get_input(&git_config, "interactive-rebase-tool.inputActionFixup", "f")?,
			input_action_pick: get_input(&git_config, "interactive-rebase-tool.inputActionPick", "p")?,
			input_action_reword: get_input(&git_config, "interactive-rebase-tool.inputActionReword", "r")?,
			input_action_squash: get_input(&git_config, "interactive-rebase-tool.inputActionSquash", "s")?,
			input_confirm_no: get_input(&git_config, "interactive-rebase-tool.inputConfirmNo", "n")?,
			input_confirm_yes: get_input(&git_config, "interactive-rebase-tool.inputConfirmYes", "y")?,
			input_edit: get_input(&git_config, "interactive-rebase-tool.inputEdit", "E")?,
			input_force_abort: get_input(&git_config, "interactive-rebase-tool.inputForceAbort", "Q")?,
			input_force_rebase: get_input(&git_config, "interactive-rebase-tool.inputForceRebase", "W")?,
			input_help: get_input(&git_config, "interactive-rebase-tool.inputHelp", "?")?,
			input_move_down: get_input(&git_config, "interactive-rebase-tool.inputMoveDown", "Down")?,
			input_move_selection_down: get_input(&git_config, "interactive-rebase-tool.inputMoveSelectionDown", "j")?,
			input_move_selection_up: get_input(&git_config, "interactive-rebase-tool.inputMoveSelectionUp", "k")?,
			input_move_up: get_input(&git_config, "interactive-rebase-tool.inputMoveUp", "Up")?,
			input_open_in_external_editor: get_input(
				&git_config,
				"interactive-rebase-tool.inputOpenInExternalEditor",
				"!",
			)?,
			input_rebase: get_input(&git_config, "interactive-rebase-tool.inputRebase", "w")?,
			input_show_commit: get_input(&git_config, "interactive-rebase-tool.inputShowCommit", "c")?,
			input_toggle_visual_mode: get_input(&git_config, "interactive-rebase-tool.inputToggleVisualMode", "v")?,
			pick_color: get_color(&git_config, "interactive-rebase-tool.pickColor", Color::Green)?,
			reword_color: get_color(&git_config, "interactive-rebase-tool.rewordColor", Color::Yellow)?,
			squash_color: get_color(&git_config, "interactive-rebase-tool.squashColor", Color::Cyan)?,
			vertical_spacing_character: get_string(
				&git_config,
				"interactive-rebase-tool.verticalSpacingCharacter",
				"~",
			)?,
		})
	}
}