//! Saved MP4s and their source ranges. Clips are never part of automatic cleanup.
use crate::{
    library::Clip,
    store::{Store, atomic_json},
};
use serde::{Deserialize, Serialize};
use std::{fs, io, path::PathBuf, time::Duration};

#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct SavedClip {
    pub clip: Clip,
    pub source_session: u64,
    pub start: Duration,
    pub end: Duration,
    pub separate_audio: bool,
}
/// Pending and failed exports retain their source leases across app restarts.
#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct PendingExport {
    pub session: u64,
    pub start: Duration,
    pub end: Duration,
    pub separate: bool,
    pub failed: bool,
}
impl Store {
    pub fn pending_exports(&self) -> io::Result<Vec<PendingExport>> {
        match fs::read(self.clips_directory().join("export-requests.json")) {
            Ok(bytes) => serde_json::from_slice(&bytes).map_err(io::Error::other),
            Err(e) if e.kind() == io::ErrorKind::NotFound => Ok(Vec::new()),
            Err(e) => Err(e),
        }
    }
    pub fn save_pending_exports(&self, exports: &[PendingExport]) -> io::Result<()> {
        atomic_json(
            &self.clips_directory().join("export-requests.json"),
            &exports,
        )
    }

    pub fn clips_directory(&self) -> PathBuf {
        self.root.parent().unwrap_or(&self.root).join("clips")
    }
    pub fn clip_path(&self, id: u64) -> PathBuf {
        self.clips_directory().join(format!("{id}.mp4"))
    }
    pub fn save_clip(&self, clip: &SavedClip) -> io::Result<()> {
        atomic_json(
            &self
                .clips_directory()
                .join(format!("{}.json", clip.clip.id)),
            clip,
        )
    }
    pub fn clips(&self) -> io::Result<Vec<SavedClip>> {
        let entries = match fs::read_dir(self.clips_directory()) {
            Ok(e) => e,
            Err(e) if e.kind() == io::ErrorKind::NotFound => return Ok(vec![]),
            Err(e) => return Err(e),
        };
        let mut clips = vec![];
        for entry in entries {
            let path = entry?.path();
            if path.extension().is_some_and(|e| e == "json")
                && path
                    .file_stem()
                    .and_then(|s| s.to_str())
                    .is_some_and(|s| s.parse::<u64>().is_ok())
            {
                let saved: SavedClip =
                    serde_json::from_slice(&fs::read(path)?).map_err(io::Error::other)?;
                if self.clip_path(saved.clip.id).is_file() {
                    clips.push(saved);
                }
            }
        }
        clips.sort_by_key(|s| std::cmp::Reverse(s.clip.created));
        Ok(clips)
    }
    pub fn delete_clip(&self, id: u64) -> io::Result<()> {
        fs::remove_file(self.clip_path(id))?;
        fs::remove_file(self.clips_directory().join(format!("{id}.json")))
    }
}
/// Launch an OS association without shell interpolation, off the UI thread.
pub fn open(path: PathBuf) -> io::Result<()> {
    #[cfg(target_os = "linux")]
    let status = std::process::Command::new("xdg-open").arg(path).status()?;
    #[cfg(windows)]
    let status = std::process::Command::new("explorer.exe")
        .arg(path)
        .status()?;
    #[cfg(not(any(target_os = "linux", windows)))]
    return Err(io::Error::other(
        "Opening files is unsupported on this platform",
    ));
    #[cfg(any(target_os = "linux", windows))]
    if status.success() {
        Ok(())
    } else {
        Err(io::Error::other(format!(
            "File opener exited with {status}"
        )))
    }
}

#[cfg(test)]
mod tests {
    use super::*;
    #[test]
    fn pending_and_failed_export_leases_round_trip_without_becoming_clips() {
        let temp = tempfile::tempdir().unwrap();
        let store = Store {
            root: temp.path().join("sessions"),
        };
        let request = PendingExport {
            session: 42,
            start: Duration::from_secs(3),
            end: Duration::from_secs(5),
            separate: false,
            failed: true,
        };
        store.save_pending_exports(&[request]).unwrap();
        let requests = store.pending_exports().unwrap();
        assert_eq!(requests.len(), 1);
        assert!(requests[0].failed);
        assert_eq!(requests[0].session, 42);
        assert!(store.clips().unwrap().is_empty());
        store.save_pending_exports(&[]).unwrap();
        assert!(store.pending_exports().unwrap().is_empty());
    }
    #[test]
    fn clips_require_a_published_mp4_and_survive_session_recovery() {
        let temp = tempfile::tempdir().unwrap();
        let store = Store {
            root: temp.path().join("sessions"),
        };
        let saved = SavedClip {
            clip: Clip {
                id: 1,
                game: "Test".into(),
                created: std::time::SystemTime::UNIX_EPOCH,
                length: Duration::from_secs(2),
                size_bytes: 4,
            },
            source_session: 42,
            start: Duration::from_secs(3),
            end: Duration::from_secs(5),
            separate_audio: false,
        };
        store.save_clip(&saved).unwrap();
        assert!(store.clips().unwrap().is_empty());
        fs::write(store.clip_path(1), b"test").unwrap();
        store.recover().unwrap();
        assert_eq!(store.clips().unwrap()[0].source_session, 42);
        let library = store.library(1).unwrap();
        assert_eq!(library.storage.clip_bytes, 4);
        assert_eq!(library.storage.unprotected_bytes, 0);
        store.delete_clip(1).unwrap();
        assert!(store.clips().unwrap().is_empty());
    }
}