use chrono::NaiveDateTime;
use diesel::pg::PgConnection as PGC;
use diesel::prelude::*;
use syntect::highlighting::ThemeSet;
use syntect::html::highlighted_html_for_string;
use syntect::parsing::SyntaxSet;

use crate::schema::snippets;

#[derive(Queryable, Serialize, Deserialize)]
pub struct Snippet {
    pub id: i32,
    pub title: String,
    pub body: String,
    pub created_at: Option<NaiveDateTime>,
    pub filetype: Option<String>,
    pub formatted_body: String,
}

#[derive(Insertable, AsChangeset, Serialize, Deserialize)]
#[table_name = "snippets"]
pub struct InsertableSnippet {
    pub title: String,
    pub body: String,
    pub filetype: Option<String>,
    pub formatted_body: String,
}

fn format_snippet(filetype: Option<String>, body: String) -> String {
    filetype.map_or(
        format!("<pre class='plaintext'>\n{}\n</pre>", body),
        |filetype| {
            let ps = SyntaxSet::load_defaults_newlines();
            let ts = ThemeSet::load_defaults();
            ps.find_syntax_by_extension(&filetype).map_or(
                format!("<pre class='plaintext'>\n{}\n</pre>", body),
                |syntax| {
                    highlighted_html_for_string(
                        &htmlescape::decode_html(&body).expect("Invalid HTML"),
                        &ps,
                        syntax,
                        &ts.themes["Solarized (light)"],
                    )
                },
            )
        },
    )
}

pub fn get(connection: &PGC, id: i32) -> QueryResult<Snippet> {
    snippets::table.find(id).get_result::<Snippet>(connection)
}

pub fn insert(snippet: InsertableSnippet, connection: &PGC) -> QueryResult<Snippet> {
    let body = htmlescape::encode_minimal(&snippet.body.clone());
    let formatted_snippet = InsertableSnippet {
        filetype: snippet.filetype.clone(),
        title: snippet.title,
        body: body.clone(),
        formatted_body: format_snippet(snippet.filetype, body),
    };
    diesel::insert_into(snippets::table)
        .values(formatted_snippet)
        .get_result(connection)
}