use handlebars::Handlebars;
use serde::Serialize;

use crate::{error::Result, site::Site};

pub struct Template {
    pub template_string: String,
}

impl Template {
    pub fn new(template_string: String) -> Self {
        Self { template_string }
    }

    pub fn generate<T: Serialize>(&self, data: &T) -> Result<String> {
        let reg = Handlebars::new();

        let output = reg.render_template(&self.template_string, data)?;
        Ok(output)
    }
}

#[cfg(test)]
mod tests {

    use super::*;
    use serde::Serialize;

    #[derive(Serialize)]
    struct TestData {
        name: String,
        age: i32,
        tags: Vec<String>,
    }

    impl Default for TestData {
        fn default() -> Self {
            Self {
                name: "Alice Allison".to_string(),
                age: 21,
                tags: vec!["cats".to_string(), "dogs".to_string(), "rust".to_string()],
            }
        }
    }

    #[test]
    fn test_template() {
        let tmpl = Template::new(
            "Hello, my name is {{ name }}, I am {{ age }} years old and i like {{#each tags}}{{this}} {{/each}}"
                .to_string(),
        );
        let res = tmpl
            .generate(&TestData::default())
            .expect("Error parsing template");
        assert_eq!(
            res,
            "Hello, my name is Alice Allison, I am 21 years old and i like cats dogs rust "
        );
    }

    #[test]
    fn html_inclusion() {
        let data = TestData {
            name: "<b>Alice</b> Allison".to_string(),
            ..Default::default()
        };

        let tmpl = Template::new(
            "Hello, my name is {{{ name }}}, I am {{ age }} years old and i like {{#each tags}}{{this}} {{/each}}"
                .to_string(),
        );

        let res = tmpl.generate(&data).expect("Error parsing template");
        assert_eq!(
            res,
            "Hello, my name is <b>Alice</b> Allison, I am 21 years old and i like cats dogs rust "
        );
    }
}