//! `warpgate cache-list` and `warpgate cache-clean` commands.

use anyhow::Result;

use crate::config::Config;
use crate::rclone::rc;

/// List cached files via rclone RC API (aggregated across all shares).
pub fn list(config: &Config) -> Result<()> {
    for (i, share) in config.shares.iter().enumerate() {
        let port = config.rc_port(i);
        println!("=== {} ===", share.name);

        let result = match rc::vfs_list(port, "/") {
            Ok(r) => r,
            Err(e) => {
                eprintln!("  Could not list cache for '{}': {}", share.name, e);
                continue;
            }
        };

        let entries = if let Some(arr) = result.as_array() {
            arr.as_slice()
        } else if let Some(list) = result.get("list").and_then(|v| v.as_array()) {
            list.as_slice()
        } else {
            println!("{}", serde_json::to_string_pretty(&result)?);
            continue;
        };

        if entries.is_empty() {
            println!("  Cache is empty.");
            continue;
        }

        println!("{:<10}  PATH", "SIZE");
        println!("{}", "-".repeat(60));

        for entry in entries {
            let name = entry.get("Name").and_then(|v| v.as_str()).unwrap_or("?");
            let size = entry.get("Size").and_then(|v| v.as_u64()).unwrap_or(0);
            let is_dir = entry
                .get("IsDir")
                .and_then(|v| v.as_bool())
                .unwrap_or(false);

            if is_dir {
                println!("{:<10}  {}/", "<dir>", name);
            } else {
                println!("{:<10}  {}", format_bytes(size), name);
            }
        }
        println!();
    }

    Ok(())
}

/// Clean cached files (only clean files, never dirty).
pub fn clean(config: &Config, all: bool) -> Result<()> {
    if all {
        println!("Clearing VFS directory cache for all shares...");
        for (i, share) in config.shares.iter().enumerate() {
            let port = config.rc_port(i);
            match rc::vfs_forget(port, "/") {
                Ok(()) => println!("  {}: cleared", share.name),
                Err(e) => eprintln!("  {}: failed — {}", share.name, e),
            }
        }
        println!("Done.");
    } else {
        println!("Current cache status:");
        for (i, share) in config.shares.iter().enumerate() {
            let port = config.rc_port(i);
            print!("  [{}] ", share.name);
            match rc::vfs_stats(port) {
                Ok(vfs) => {
                    if let Some(dc) = vfs.disk_cache {
                        println!(
                            "Used: {}, Uploading: {}, Queued: {}",
                            format_bytes(dc.bytes_used),
                            dc.uploads_in_progress,
                            dc.uploads_queued
                        );
                    } else {
                        println!("no cache stats");
                    }
                }
                Err(e) => println!("unreachable — {}", e),
            }
        }
        println!("\nRun with --all to clear the directory cache.");
    }
    Ok(())
}

fn format_bytes(bytes: u64) -> String {
    const KIB: f64 = 1024.0;
    const MIB: f64 = KIB * 1024.0;
    const GIB: f64 = MIB * 1024.0;

    let b = bytes as f64;
    if b >= GIB {
        format!("{:.1} GiB", b / GIB)
    } else if b >= MIB {
        format!("{:.1} MiB", b / MIB)
    } else if b >= KIB {
        format!("{:.1} KiB", b / KIB)
    } else {
        format!("{} B", bytes)
    }
}

#[cfg(test)]
mod tests {
    use super::*;

    #[test]
    fn test_format_bytes_zero() {
        assert_eq!(format_bytes(0), "0 B");
    }

    #[test]
    fn test_format_bytes_kib() {
        assert_eq!(format_bytes(2048), "2.0 KiB");
    }

    #[test]
    fn test_format_bytes_mib() {
        assert_eq!(format_bytes(5242880), "5.0 MiB");
    }

    #[test]
    fn test_format_bytes_gib() {
        assert_eq!(format_bytes(10737418240), "10.0 GiB");
    }
}