/*! Utility functions for variety of tasks */
//
// Copyright 2020, Jesús Pérez Lorenzo

use std::collections::HashMap;
use std::fs;
use std::path::Path;
use tera::{Tera};

/// make content from template path: from `root_path` + extension search for ".toml" or ".json"
/// template should be `root_path`.html and lang should be included in `root_path`
// #[must_use]
#[allow(clippy::implicit_hasher)]
#[allow(dead_code)]
pub fn make_template_content(
  root_path: &str,
  ctx: &mut tera::Context,
  data_hash: &mut HashMap<String, String>,
  load_extend: bool,
) -> String {
  let mut data_path = format!("{}.toml", &root_path);
  if !Path::new(&data_path).exists() {
    data_path = format!("{}.json", &root_path);
  }
  match hash_from_data(&data_path,ctx,data_hash,load_extend) {
    Ok(_) => match data_templated(
      "",
      format!("{}.html", &root_path).as_str(),
      ctx,
      data_hash,
    ) {
      Ok(templated_file) => return templated_file,
      Err(e) => println!(
        "Error generating template {}.html: {}",
        &root_path, e
      ),
    },
    Err(e) => println!(
      "Error with data template {} - {} : {}",
      &root_path, &data_path, e
    ),
  }
  "".to_string()
}
/// `get_json_val` is a simple match Option to remove quotes in json values and returned as a String
#[must_use]
pub fn get_json_val(json_value: &serde_json::Value, dflt_val: String) -> String {
  match json_value.as_str() {
    Some(val) => val.to_string(),
    None => dflt_val,
  }
}
/// `get_toml_val` is a simple match Option to remove quotes in json values and returned as a String
#[must_use]
pub fn get_toml_val(toml_value: &toml::Value, dflt_val: String) -> String {
  match toml_value.as_str() {
    Some(val) => val.to_string(),
    None => dflt_val,
  }
}
/// `get_toml_val` is a simple match Option to remove quotes in json values and returned as a String
#[must_use]
pub fn get_yaml_val(yaml_value: &serde_yaml::Value, dflt_val: String) -> String {
  match yaml_value.as_str() {
    Some(val) => val.to_string(),
    None => dflt_val,
  }
}
/// Load a data file, fill a receive HASH, load template file and applied with Tera
/// By file extension is able to load data from JSON or TOML (as a table Value)
///
/// Unwrap lines in the following example has to be changed to "matched" or ? with -> Result<>
///```rust
/// let mut data_hash: HashMap<String, String> = HashMap::new();
/// let path = String::from("resources/mail/test.json".to_string());
/// let res = hash_from_data(&data_path, &mut data_hash).unwrap();
/// let root_path = String::from("resources/mail");
/// let tpl_result = data_templated(&root_path,"test.html",&res).unwrap();
/// ```
#[allow(clippy::missing_errors_doc,clippy::implicit_hasher)]
// 
pub fn hash_from_data(path: &str, ctx: &mut tera::Context, data_hash: &mut HashMap<String, String>, load_extend: bool) -> anyhow::Result<()> {
  // {HashMap<String, String>> {
  let mut check_value = | key: String, v: String | {
    if let Some(first_char) = v.chars().next() {
      if first_char == '@' {
        let field_file = &v[1..];
        let _ = hash_from_data(field_file, ctx, data_hash, load_extend);
        //  dbg!("{}",&data_hash);
        return;
      }
    }
    data_hash.insert(key, v);
  };
  let vars_content = fs::read_to_string(&path)?;
  //let mut data_hash: HashMap<String, String> = HashMap::new();
  if let Some(extension) = path.split('.').last() {
    //println!("File {} extension {}", &path, &extension);
    match extension {
      "json" => {
        let data: HashMap<String, serde_json::Value> = serde_json::from_str(&vars_content)?;
        if load_extend {
          match tera::Context::from_serialize(data) {
            Ok(res) => {
              ctx.extend(res); 
            },
            Err(e) => {
              println!("Error loading {}: {}",&path, e);
            },
          }
        } else {
          for (key, value) in data {
            let val = get_json_val(&value, "".into());
            check_value(key,val);
          }
        }
      }
      "toml" => {
        // As a table content
        let data: toml::Value = toml::from_str(&vars_content)?;
        // let data = &vars_content.parse::<toml::Value>()?;
        if load_extend {
          match tera::Context::from_serialize(data) {
            Ok(res) => {
              ctx.extend(res); 
            },
            Err(e) => {
              println!("Error loading {}: {}",&path, e);
            },
          }
        } else if let Some(table_data) = data.as_table() {
            for (key, value) in table_data {
              // println!("-{}-{}",&key,&value);
              let val = get_toml_val(&value, "".into());
              check_value(key.into(),val);
            }
        }
      }
      "yaml" => {
        let data: HashMap<String, serde_yaml::Value> = serde_yaml::from_str(&vars_content)?;
        if load_extend {
          match tera::Context::from_serialize(data) {
            Ok(res) => {
              ctx.extend(res); 
            },
            Err(e) => {
              println!("Error loading {}: {}",&path, e);
            },
          }
        } else {
          for (key, value) in data {
            let val = get_yaml_val(&value, "".into());
            check_value(key,val);
          }
        }
      }
      _ => {
        println!(
          "File {} format extension {} not defined ",
          &path, &extension
        );
      }
    }
  } else {
    println!("File {} unknown extension", &path);
  }
  // dbg!(&data_hash);
  Ok(()) // data_hash)
}
/// Data tempalted create a Tera context form hashmap and reads a file template from path/template_name
/// Finally render to a String
#[allow(clippy::missing_errors_doc, clippy::implicit_hasher)]
pub fn data_templated(
  path: &str,
  template_name: &str,
  tpl_context: &mut tera::Context,
  content: &HashMap<String, String>,
) -> anyhow::Result<String> {
  // let mut tpl_context = Context::new();
  for (key, value) in content.iter() {
    tpl_context.insert(key, value);
  }
  let mut tera = Tera::default();

  let template_head = "header.html";
  let tpl = read_path_file(&path, &template_name, "content")?;
  let mut all_tpls = vec![("data-template.html",tpl)];
  match read_path_file(&path, &template_head, "content") {
    Ok(tpl_head) =>  all_tpls.push((&template_head,tpl_head)),
    Err(_) => {} // ignore if no header
  }
  tera.add_raw_templates(all_tpls)?;
  let res = tera.render("data-template.html", &tpl_context)?;
	Ok(res.replace("&#x2F;","/"))
}
/// Read a `file_name` from a path (root / `file_name`) ( "" `file_name_full_path` )
/// format of reading can be matched with `file_type`
/// TODO implement other types to read
#[allow(clippy::missing_errors_doc)]
pub fn read_path_file(path: &str, file_name: &str, file_type: &str) -> anyhow::Result<String> {
  let mut result = String::from("");
  let mut root_path = format!("{}/", path);
  if root_path.as_str() == "/" {
    root_path = String::from("");
  }
  //println!("{}",format!("{}{}", &root_path.as_str(), &file_name));
  match file_type {
    "content" => {
      result = fs::read_to_string(format!("{}{}", &root_path.as_str(), &file_name).as_str())?
    }
    _ => println!(
      "File {}{} type {} not defined ",
      &root_path, &file_name, &file_type
    ),
  }
  Ok(result)
}