use crate::models::{CookieSource, VideoMetadata};
use crate::services::{download_manager, video_resolver};
use serde::Serialize;
use std::io::{BufRead, BufReader};
use tauri::ipc::Channel;

#[tauri::command]
pub async fn resolve_url(
    url: String,
    cookie_source: CookieSource,
) -> Result<VideoMetadata, String> {
    tokio::task::spawn_blocking(move || video_resolver::resolve(&url, &cookie_source))
        .await
        .map_err(|e| format!("Task failed: {e}"))?
}

#[derive(Clone, Serialize)]
#[serde(rename_all = "camelCase", tag = "event", content = "data")]
pub enum DownloadEvent {
    Progress { percent: f64 },
    FilePath { path: String },
    Finished { success: bool, path: String },
    Error { message: String },
}

#[tauri::command]
pub async fn start_download(
    url: String,
    cookie_source: CookieSource,
    on_event: Channel<DownloadEvent>,
) -> Result<(), String> {
    tokio::task::spawn_blocking(move || {
        let temp_dir = std::env::temp_dir()
            .join("video-clipper")
            .to_string_lossy()
            .to_string();
        std::fs::create_dir_all(&temp_dir)
            .map_err(|e| format!("Failed to create temp dir: {e}"))?;

        let (mut child, _template) =
            download_manager::start_download(&url, &cookie_source, &temp_dir)?;

        let Some(stderr) = child.stderr.take() else {
            let status = child
                .wait()
                .map_err(|e| format!("Download failed: {e}"))?;
            let _ = on_event.send(DownloadEvent::Finished {
                success: status.success(),
                path: String::new(),
            });
            return Ok(());
        };

        let reader = BufReader::new(stderr);
        let mut last_file_path: Option<String> = None;

        for line in reader.lines().map_while(Result::ok) {
            if let Some(pct) = download_manager::parse_progress_line(&line) {
                let _ = on_event.send(DownloadEvent::Progress { percent: pct });
            }

            if line.contains("[download] Destination:")
                || line.contains("[Merger] Merging formats into")
            {
                if let Some(path) = line.split(": ").nth(1) {
                    let trimmed = path.trim().trim_matches('"').to_string();
                    let _ = on_event.send(DownloadEvent::FilePath {
                        path: trimmed.clone(),
                    });
                    last_file_path = Some(trimmed);
                }
            }
        }

        let status = child
            .wait()
            .map_err(|e| format!("Download failed: {e}"))?;
        let path = last_file_path.unwrap_or_default();
        let _ = on_event.send(DownloadEvent::Finished {
            success: status.success(),
            path,
        });

        Ok(())
    })
    .await
    .map_err(|e| format!("Task failed: {e}"))?
}