/*
 * Copyright 2025 Bryson Steck <me@brysonsteck.xyz>
 *
 * This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at https://mozilla.org/MPL/2.0/.
 */

use crate::common;
use crate::refractr::Refractr;

use core::fmt;
use serde_derive::Deserialize;
use std::env;
use std::fs::{self, File, Metadata};
use std::io::Read;
use std::path::PathBuf;
use toml;

pub struct ConfigFile {
  pub path: String,
  pub file: Metadata,
  pub config: Config,
}

impl fmt::Display for ConfigFile {
  fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
    let mut branches_list = String::from("[");
    for i in 0..self.config.branches.len() {
      branches_list = format!("{}{}", branches_list, &self.config.branches[i]);
      if i < self.config.branches.len() - 1 {
        branches_list.push_str(", ");
      }
    }
    branches_list.push(']');

    let mut to_list = String::from("[");
    for i in 0..self.config.to.len() {
      to_list.push_str(&self.config.to[i]);
      if i < self.config.to.len() - 1 {
        to_list.push_str(", ");
      }
    }
    to_list.push(']');

    let work_dir_path = match &self.config.work_dir {
      None => {
        if cfg!(windows) {
          format!(
            "Using default \"{}\\refractr\"",
            match env::var("TEMP") {
              Ok(val) => val,
              Err(_) => format!("This shouldn't happen!"),
            }
          )
        } else {
          format!("Using default: /tmp/refractr")
        }
      },
      Some(path) => format!("{}", path),
    };

    let schedule_interval = match self.config.schedule.interval {
      None => {
        if !self.config.schedule.enabled {
          String::from("")
        } else {
          String::from("This shouldn't happen!\n")
        }
      },
      Some(int) => format!(
        "\n        Scheduled interval in seconds: {}",
        int.to_string()
      ),
    };

    write!(
      f,
      "Config file: \"{}\"\n      \
        Is a file: {}\n      \
        Read only: {}\n      \
        Configuration:\n        \
        Git repo to clone: {}\n        \
        Git repos to push clone to: {}\n        \
        Branches of clone to push: {}\n        \
        Working directory: {}\n        \
        SSH key for pushing clone: {}\n        \
        Schedule enabled: {}\
        {}",
      self.path,
      self.file.is_file(),
      self.file.permissions().readonly(),
      self.config.from,
      to_list,
      branches_list,
      work_dir_path,
      self.config.git.ssh_identity_file,
      self.config.schedule.enabled,
      schedule_interval
    )
  }
}

#[derive(PartialEq, Deserialize)]
pub struct Config {
  pub from: String,
  pub to: Vec<String>,
  pub branches: Vec<String>,
  pub work_dir: Option<String>,
  pub git: Git,
  pub schedule: Schedule,
}

#[derive(PartialEq, Deserialize)]
pub struct Git {
  pub ssh_identity_file: String,
}

#[derive(PartialEq, Deserialize)]
pub struct Schedule {
  pub enabled: bool,
  pub interval: Option<i32>,
}

pub fn read_config(paths: Vec<PathBuf>, refractr: &Refractr) -> Result<Vec<ConfigFile>, String> {
  let mut config_files: Vec<ConfigFile> = vec![];
  for path in paths {
    common::verbose(
      refractr.verbose,
      1,
      format!(
        "Reading config file: \"{}\"",
        String::from(path.to_string_lossy())
      ),
    );
    let mut data = String::new();
    let mut file = match File::open(path.as_path()) {
      Err(e) => {
        return Err(format!(
          "unable to open {}: {}",
          path.as_path().display(),
          e
        ))
      },
      Ok(file) => file,
    };

    if let Err(e) = file.read_to_string(&mut data) {
      return Err(format!(
        "unable to read {}: {}",
        path.as_path().display(),
        e
      ));
    }

    let config: Config = match toml::from_str(&data) {
      Ok(c) => c,
      Err(e) => {
        return Err(format!(
          "issues parsing toml file {}: {}",
          path.as_path().display(),
          e
        ))
      },
    };

    let config_file = ConfigFile {
      path: match fs::canonicalize(&path) {
        Err(_) => {
          return Err(format!(
            "cannot get absolute path of config file: {}",
            path.as_path().display()
          ))
        },
        Ok(abs) => abs.to_string_lossy().to_string(),
      },
      file: match fs::metadata(&path) {
        Err(_) => {
          return Err(format!(
            "cannot obtain metadata for config file: {}",
            path.as_path().display()
          ))
        },
        Ok(metadata) => metadata,
      },
      config: match verify_config(&config) {
        Err(e) => {
          return Err(format!(
            "invalid config {}: {}",
            path.as_path().display(),
            e
          ))
        },
        Ok(_) => config,
      },
    };

    let mut dup = false;
    for i in &config_files {
      if i.path == config_file.path {
        common::warning(format!(
          "skipping config file \"{}\" as it was already read",
          path.as_path().display()
        ));
        dup = true;
        break;
      } else if i.config == config_file.config {
        common::warning(format!(
          "config files \"{}\" and \"{}\" appear to have the same config",
          i.path, config_file.path
        ));
      }
    }

    if !dup {
      config_files.push(config_file);
    }
  }

  return Ok(config_files);
}

fn verify_config(config: &Config) -> Result<(), String> {
  if config.schedule.enabled {
    match config.schedule.interval {
      Some(i) => {
        if i < 60 {
          return Err(format!("schedule is enabled, but less than 60"));
        }
      },
      None => return Err(format!("schedule is enabled, but no interval was defined")),
    }
  }

  match &config.work_dir {
    Some(path) => format!("{}", path),
    None => {
      if cfg!(windows) {
        match env::var("TEMP") {
          Ok(val) => val,
          Err(_) => return Err(format!("cannot determine the default temp dir")),
        }
      } else {
        format!("/tmp/refractr")
      }
    },
  };

  if !&config.from.starts_with("ssh://")
    && !&config.from.starts_with("https://")
    && !&config.from.starts_with("http://")
  {
    return Err(format!("'from' value does not use a supported protocol"));
  }

  Ok(())
}