//! Windows Taskbar Jump List — recent vaults.
//!
//! Populates the taskbar jump list with the configured vaults so the user can
//! jump straight into a vault from the Windows taskbar / Start menu.
//!
//! Best-effort: every step is fallible and logged, never panics, and a failure
//! simply leaves the jump list at its OS-managed default state.

use log::{info, warn};

#[cfg(target_os = "windows")]
mod imp {
    use super::*;
    use std::os::windows::ffi::OsStrExt;
    use windows::core::{Interface, HSTRING, PCWSTR};
    use windows::Win32::Foundation::PROPERTYKEY;
    use windows::Win32::System::Com::{
        CoCreateInstance, CoInitializeEx, CLSCTX_INPROC_SERVER, COINIT_APARTMENTTHREADED,
    };
    use windows::Win32::System::Com::StructuredStorage::PROPVARIANT;
    use windows::Win32::System::Variant::VT_LPWSTR;
    use windows::Win32::UI::Shell::{
        ICustomDestinationList, IShellLinkW, SetCurrentProcessExplicitAppUserModelID,
        DestinationList, EnumerableObjectCollection, ShellLink,
    };
    use windows::Win32::UI::Shell::Common::IObjectCollection;
    use windows::Win32::UI::Shell::PropertiesSystem::IPropertyStore;

    const APP_ID: &str = "com.obsigate.desktop";

    // PKEY_Title (System.Title): {F29F85E0-4FF9-1068-AB91-08002B27B3D9}, pid 2
    const PKEY_TITLE: PROPERTYKEY = PROPERTYKEY {
        fmtid: windows::core::GUID::from_u128(0xF29F85E0_4FF9_1068_AB91_08002B27B3D9),
        pid: 2,
    };

    fn wide_null_terminated(s: &str) -> Vec<u16> {
        std::ffi::OsStr::new(s).encode_wide().chain(std::iter::once(0)).collect()
    }

    /// Set the jump-list display title via the shell link's property store.
    fn set_link_title(link: &IShellLinkW, title: &str) -> windows::core::Result<()> {
        let store: IPropertyStore = link.cast()?;
        let mut wide = wide_null_terminated(title);
        let mut pv: PROPVARIANT = unsafe { std::mem::zeroed() };
        unsafe {
            let inner = &mut *pv.Anonymous.Anonymous;
            inner.vt = VT_LPWSTR;
            inner.Anonymous.pwszVal = windows::core::PWSTR(wide.as_mut_ptr());
            store.SetValue(&PKEY_TITLE, &pv)?;
            store.Commit()?;
        }
        Ok(())
    }

    /// Build one shell link for a vault. `arg` is the command-line argument the
    /// app expects to open that vault (see file associations / single-instance).
    fn build_shell_link(name: &str, arg: &str) -> windows::core::Result<IShellLinkW> {
        let link: IShellLinkW =
            unsafe { CoCreateInstance(&ShellLink, None, CLSCTX_INPROC_SERVER)? };

        let exe = std::env::current_exe()
            .map_err(|e| windows::core::Error::from(std::io::Error::other(e)))?;
        let exe_wide = exe.as_os_str().encode_wide().chain(std::iter::once(0)).collect::<Vec<u16>>();

        unsafe {
            link.SetPath(PCWSTR(exe_wide.as_ptr()))?;
            if !arg.is_empty() {
                link.SetArguments(&HSTRING::from(arg))?;
            }
            link.SetDescription(&HSTRING::from(name))?;
        }
        // Title (display name) is best-effort — a missing title only means the
        // jump-list entry falls back to the executable name.
        let _ = set_link_title(&link, name);
        Ok(link)
    }

    /// Populate the jump list with the given (name, arg) vault entries.
    pub fn update_jumplist(vaults: &[(String, String)]) {
        // COM must be initialised on this thread.
        let _ = unsafe { CoInitializeEx(None, COINIT_APARTMENTTHREADED) };

        let result = (|| -> windows::core::Result<()> {
            unsafe {
                SetCurrentProcessExplicitAppUserModelID(PCWSTR(wide_null_terminated(APP_ID).as_ptr()))?;
            }

            let list: ICustomDestinationList =
                unsafe { CoCreateInstance(&DestinationList, None, CLSCTX_INPROC_SERVER)? };

            let mut min_slots = 0u32;
            unsafe {
                list.BeginList::<windows::core::IUnknown>(&mut min_slots)?;
            }

            // "Vaults" category
            let collection: IObjectCollection = unsafe {
                CoCreateInstance(&EnumerableObjectCollection, None, CLSCTX_INPROC_SERVER)?
            };
            for (name, arg) in vaults {
                match build_shell_link(name, arg) {
                    Ok(link) => unsafe {
                        let _ = collection.AddObject(&link);
                    },
                    Err(e) => warn!("jumplist: failed to build link for {}: {}", name, e),
                }
            }
            unsafe {
                let array: windows::Win32::UI::Shell::Common::IObjectArray = collection.cast()?;
                list.AppendCategory(&HSTRING::from("Vaults"), &array)?;
                list.CommitList()?;
            }
            Ok(())
        })();

        match result {
            Ok(()) => info!("jumplist updated with {} vaults", vaults.len()),
            Err(e) => warn!("jumplist update failed (non-fatal): {}", e),
        }
    }
}

#[cfg(not(target_os = "windows"))]
mod imp {
    use super::*;

    /// No-op on non-Windows platforms.
    pub fn update_jumplist(_vaults: &[(String, String)]) {
        info!("jumplist is Windows-only — skipped");
    }
}

/// Public entry point: update the Windows jump list from the configured vaults.
/// Each entry maps a vault name to the CLI argument the app accepts to open it.
pub fn update_jumplist(vaults: &[(String, String)]) {
    imp::update_jumplist(vaults);
}

/// Build the (name, arg) pairs for the jump list from vault paths.
/// Pure helper so the mapping is unit-testable on every platform.
pub fn build_vault_args(vaults: &[crate::VaultConfig]) -> Vec<(String, String)> {
    vaults
        .iter()
        .map(|v| (v.name.clone(), format!("--vault={}", v.path)))
        .collect()
}

#[cfg(test)]
mod tests {
    use super::build_vault_args;
    use crate::VaultConfig;

    fn v(name: &str, path: &str) -> VaultConfig {
        VaultConfig { name: name.to_string(), path: path.to_string() }
    }

    #[test]
    fn test_build_vault_args_empty() {
        assert!(build_vault_args(&[]).is_empty());
    }

    #[test]
    fn test_build_vault_args_maps_name_and_path() {
        let vaults = vec![v("Perso", "C:\\vaults\\perso"), v("IT", "/home/bruno/IT")];
        let args = build_vault_args(&vaults);
        assert_eq!(args.len(), 2);
        assert_eq!(args[0], ("Perso".to_string(), "--vault=C:\\vaults\\perso".to_string()));
        assert_eq!(args[1], ("IT".to_string(), "--vault=/home/bruno/IT".to_string()));
    }

    #[test]
    fn test_build_vault_args_preserves_order() {
        let vaults = vec![v("a", "/a"), v("b", "/b"), v("c", "/c")];
        let args = build_vault_args(&vaults);
        assert_eq!(args.iter().map(|(n, _)| n.as_str()).collect::<Vec<_>>(), vec!["a", "b", "c"]);
    }
}