/*
 * This is the echoip-slatecave templating engine.
 * It wraps around tera in is specialized for echoip-slatecave.
 */

use axum::{
	http::StatusCode,
	response::Html,
	response::IntoResponse,
	response::Response,
	response::Json,
};
use tera::Tera;
use toml::Table;

use std::net::IpAddr;

use crate::simple_dns;
use crate::IpResult;

/* Response format */

#[derive(serde::Deserialize, serde::Serialize, Clone, Copy)]
pub enum ResponseFormat {
	#[serde(rename="text/plain", alias="text")]
	TextPlain,
	#[serde(rename="text/html", alias="html")]
	TextHtml,
	#[serde(rename="application/json", alias="json")]
	ApplicationJson,
}

impl ToString for ResponseFormat {
	fn to_string(&self) -> String {
		match self {
			ResponseFormat::TextPlain => "text/plain",
			ResponseFormat::TextHtml => "text/html",
			ResponseFormat::ApplicationJson => "application/json",
		}.to_string()
	}
}

/* Template Settings */

#[derive(serde::Deserialize, serde::Serialize, Clone)]
pub struct TemplateSettings {
	pub format: ResponseFormat,
	pub lang: String,
}

/* The echoip view */

#[derive(serde::Deserialize, serde::Serialize, Clone)]
#[serde(untagged)]
pub enum View {
	Dig { query: String, result: simple_dns::DnsLookupResult },
	Index { query: IpAddr, result: IpResult, user_agent: Option<String> },
	Ip { query: IpAddr, result: IpResult },
	Message{ title: String, message: String },
	#[serde(rename="404")]
	NotFound,
}

impl View {
	pub fn template_name(&self) -> String {
		match self {
			View::Dig{..} => "dig",
			View::Index{..} => "index",
			View::Ip{..} => "ip",
			View::Message{..} => "message",
			View::NotFound => "404",
		}.to_string()
	}
}

/* The engine itself */

#[derive(Clone)]
pub struct Engine {
	pub tera: Tera,
	pub template_config: Option<Table>,
}

impl Engine {
	pub async fn render_view(
		&self,
		settings: &TemplateSettings,
		view: &View,
	) -> Response {
		match settings.format {
			ResponseFormat::TextHtml => {
				let template_name = view.template_name();

				let mut context = tera::Context::new();
				context.insert("view", &template_name);
				//intented for shared macros
				context.insert("format", &settings.format.to_string());
				context.insert("language", &settings.lang);
				context.insert("data", &view);
				context.insert("extra", &self.template_config);

				match self.tera.render(&(template_name+".html"), &context) {
					Ok(html) => Html(html).into_response(),
					Err(e) => {
						println!("There was an error while rendering index.html: {e:?}");
						StatusCode::INTERNAL_SERVER_ERROR.into_response()
					}
				}
			}
			//TODO: Plain Text should have its own matcher
			ResponseFormat::ApplicationJson | ResponseFormat::TextPlain => {
				match view {
					View::Dig{result, ..} => {
						Json(result).into_response()
					},
					View::Index{result, ..} | View::Ip{result, ..} => {
						Json(result).into_response()
					},
					_ => Json(view).into_response(),
				}
			}
		}
	}
}