use crate::config::Config;
use once_cell::sync::Lazy;
use serde_json::Value;
use std::{collections::HashMap, fs, path::Path};
use sys_locale;

pub fn get_supported_languages() -> Vec<String> {
    let project_dir = Path::new(env!("CARGO_MANIFEST_DIR")).parent().unwrap();
    let i18n_path = project_dir.join("src/services/i18n.ts");

    if let Ok(content) = fs::read_to_string(i18n_path) {
        let mut languages = Vec::new();
        for line in content.lines() {
            if line.contains("resources = {") {
                for line in content.lines() {
                    if let Some(lang) = line.trim().strip_suffix(": { translation:") {
                        let lang = lang.trim().trim_matches('"');
                        if !lang.is_empty() {
                            languages.push(lang.to_string());
                        }
                    }
                    if line.contains("};") {
                        break;
                    }
                }
                break;
            }
        }
        if !languages.is_empty() {
            return languages;
        }
    }

    vec![
        "en".to_string(),
        "ru".to_string(),
        "zh".to_string(),
        "fa".to_string(),
    ]
}

static TRANSLATIONS: Lazy<HashMap<String, Value>> = Lazy::new(|| {
    let project_dir = Path::new(env!("CARGO_MANIFEST_DIR")).parent().unwrap();
    let locales_dir = project_dir.join("src/locales");
    let mut translations = HashMap::new();

    for lang in ["en", "ru", "zh", "fa", "tt"] {
        let file_path = locales_dir.join(format!("{}.json", lang));
        if let Ok(content) = fs::read_to_string(file_path) {
            if let Ok(json) = serde_json::from_str(&content) {
                translations.insert(lang.to_string(), json);
            }
        }
    }
    translations
});

pub fn t(key: &str) -> String {
    let config = Config::verge();
    let verge = config.latest();
    let current_lang = verge
        .language
        .as_ref()
        .map_or_else(|| get_system_language(), |lang| lang.to_string());

    if let Some(translations) = TRANSLATIONS.get(&current_lang) {
        if let Some(text) = translations.get(key) {
            if let Some(text) = text.as_str() {
                return text.to_string();
            }
        }
    }

    // Fallback to English
    if let Some(translations) = TRANSLATIONS.get("en") {
        if let Some(text) = translations.get(key) {
            if let Some(text) = text.as_str() {
                return text.to_string();
            }
        }
    }

    key.to_string()
}

fn get_system_language() -> String {
    let sys_lang = sys_locale::get_locale()
        .unwrap_or_else(|| String::from("en"))
        .to_lowercase();

    let lang_code = sys_lang.split(['_', '-']).next().unwrap_or("en");
    let supported_languages = get_supported_languages();

    if supported_languages.contains(&lang_code.to_string()) {
        lang_code.to_string()
    } else {
        String::from("en")
    }
}