// This file is part of Locus <https://github.com/gemrest/locus>.
// Copyright (C) 2022-2022 Fuwn <contact@fuwn.me>
//
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, version 3.
//
// This program is distributed in the hope that it will be useful, but
// WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
// General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with this program. If not, see <http://www.gnu.org/licenses/>.
//
// Copyright (C) 2022-2022 Fuwn <contact@fuwn.me>
// SPDX-License-Identifier: GPL-3.0-only

use std::lazy::SyncLazy;

use serde::Deserialize;

use crate::{route::track_mount, success};

static REFERRALS: SyncLazy<Vec<Referral>> = SyncLazy::new(|| {
  serde_json::from_str(include_str!("../../content/json/stock_referrals.json"))
    .unwrap()
});

#[derive(Deserialize)]
struct Referral {
  name:        String,
  description: String,
  url:         String,
}

#[derive(Deserialize, Debug)]
struct Quote {
  c:  f64,
  d:  Option<f64>,
  dp: Option<f64>,
  h:  f64,
  l:  f64,
  o:  f64,
  pc: f64,
  #[allow(unused)]
  t:  i64,
}

impl Quote {
  pub fn try_to_string(&self) -> Result<String, ()> {
    Ok(format!(
      "Current Price: ${}\nDaily Change: ${} ({}%)\nHigh of the Day: ${}\nLow \
       of the Day: ${}\nOpening Price: ${}\nYesterday's Closing Price: ${}",
      self.c,
      if let Some(d) = self.d {
        d
      } else {
        return Err(());
      },
      if let Some(dp) = self.dp {
        dp
      } else {
        return Err(());
      },
      self.l,
      self.h,
      self.o,
      self.pc,
    ))
  }
}

fn symbol_to_string(symbol: &str) -> String {
  let mut quote = None;

  if let Ok(response) = reqwest::blocking::get(format!(
    "https://finnhub.io/api/v1/quote?symbol={}&token={}",
    symbol,
    std::env::var("FINNHUB_TOKEN")
      .expect("could not locate FINNHUB_TOKEN environment variable")
  )) {
    if let Ok(response_content) = response.json::<Quote>() {
      if response_content.dp.is_some() {
        quote = Some(response_content);
      } else {
        return "You have searched for an invalid symbol.".to_string();
      }
    }
  }

  quote.as_ref().map_or_else(
    || {
      format!(
        "An API error has occurred while looking up the {} symbol... Take \
         this up with Finnhub.",
        symbol
      )
    },
    |quote| quote.try_to_string().unwrap(),
  )
}

pub fn module(router: &mut windmark::Router) {
  track_mount(
    router,
    "/stocks/referrals",
    "Want to start investing? Support me by using one of my referral links!",
    Box::new(|context| {
      success!(
        format!(
          "# Referrals\n\n=> /stocks Home\n=> /stocks/search?action=go \
           Search!\n\nWant to start investing? Support me by using one of my \
           referral links!\n\n{}",
          REFERRALS
            .iter()
            .map(|r| {
              format!("## {}\n\n{}\n\n=> {} {0}", r.name, r.description, r.url)
            })
            .collect::<Vec<String>>()
            .join("\n")
        ),
        context
      )
    }),
  );

  track_mount(
    router,
    "/stocks",
    "Explore and search the stock market using Gemini!",
    Box::new(|context| {
      success!(
        format!(
          "# Stocks\n\n=> /stocks/search Symbol Search\n=> /stocks/referrals Referrals\n\n## Popular \
           Symbols\n\n### AAPL\n\n{}\n\n### TSLA\n\n{}\n\n## Credits\n\nFinancial data provided by\n\n=> https://finnhub.io/ Finnhub",
          symbol_to_string("AAPL"),
          symbol_to_string("TSLA")
        ),
        context
      )
    }),
  );

  track_mount(
    router,
    "/stocks/search",
    "Search for a specific symbol",
    Box::new(|context| {
      let mut symbol = context.url.query().unwrap_or("Symbol Search");

      if symbol.is_empty() {
        symbol = "Symbol Search";
      }

      let mut response = format!(
        "# {}\n\n=> /stocks Home\n=> /stocks/search?action=go Search!",
        symbol
      );

      if symbol != "Symbol Search" {
        if let Some(query) = context.url.query_pairs().next() {
          if query.0 == "action" && query.1 == "go" {
            return windmark::Response::Input(
              "Which symbol would you like to explore?".to_string(),
            );
          }

          let symbol = query.0;

          if symbol != "Symbol Search" {
            response = format!(
              "{}\n\nYou searched for \"{}\"!\n\n## Key Statistics\n\n{}",
              response,
              symbol,
              symbol_to_string(&symbol)
            );
          }
        }
      }

      success!(
        format!(
          "{}\n\n## Credits\n\nFinancial data provided by\n\n=> https://finnhub.io/ Finnhub",
          response
        ),
        context
      )
    }),
  );
}