//! Keyboard bindings — the web port of `cbd-tui/src/app/bindings.rs`,
//! keyed by browser `KeyboardEvent` values instead of crossterm codes.
//! Deliberate differences: there is no `q` (quit) in a browser tab, and
//! `Escape` closes the help overlay (the TUI also accepts `q`/`?`).

use crate::state::Focus;

/// Everything a key can trigger. Mirrors the TUI's `Action` list; the
/// components translate these into RPCs or local state changes.
#[derive(Clone, Copy, Debug, PartialEq, Eq)]
pub enum Action {
    OpenHelp,
    CloseHelp,
    CycleFocus,
    TogglePlay,
    RestartTrack,
    VolumeUp,
    VolumeDown,
    ToggleMute,
    ToggleShuffle,
    ToggleRepeat,
    NextTrack,
    PrevTrack,
    LibraryFirst,
    LibraryLast,
    LibraryNext,
    LibraryPrev,
    LibraryJumpDown,
    LibraryJumpUp,
    LibraryAscend,
    LibraryDive,
    LibraryToggleMark,
    LibraryCaptureNode,
    LibraryDownloadNode,
    LibraryCreateNode,
    LibraryEditNode,
    LibraryDeleteNode,
    LibraryQueueAppend,
    LibraryQueueNext,
    LibraryQueueReplace,
    QueueFirst,
    QueueLast,
    QueueNext,
    QueuePrev,
    QueueJumpDown,
    QueueJumpUp,
    QueueSelectCurrent,
    QueuePlaySelected,
    QueueInsertHere,
    QueueRemoveTrack,
    QueueClearKeepCurrent,
    QueueClearAll,
    QueueSaveAs,
}

/// One row of the help overlay: the key label and what it does.
pub struct HelpEntry {
    pub scope: &'static str,
    pub key: &'static str,
    pub description: &'static str,
}

/// The help overlay content, in display order — kept in lockstep with
/// [`lookup`] by the unit tests below.
pub const HELP: &[HelpEntry] = &[
    HelpEntry {
        scope: "Global",
        key: "?",
        description: "Show this help",
    },
    HelpEntry {
        scope: "Global",
        key: "Tab",
        description: "Switch between library and queue",
    },
    HelpEntry {
        scope: "Global",
        key: "Space",
        description: "Play/pause",
    },
    HelpEntry {
        scope: "Global",
        key: "r",
        description: "Restart current track",
    },
    HelpEntry {
        scope: "Global",
        key: "K",
        description: "Volume up",
    },
    HelpEntry {
        scope: "Global",
        key: "J",
        description: "Volume down",
    },
    HelpEntry {
        scope: "Global",
        key: "m",
        description: "Toggle mute",
    },
    HelpEntry {
        scope: "Global",
        key: "z",
        description: "Toggle shuffle",
    },
    HelpEntry {
        scope: "Global",
        key: "x",
        description: "Toggle repeat",
    },
    HelpEntry {
        scope: "Global",
        key: "Ctrl-n",
        description: "Next track",
    },
    HelpEntry {
        scope: "Global",
        key: "Ctrl-p",
        description: "Previous track",
    },
    HelpEntry {
        scope: "Library",
        key: "j / k",
        description: "Select next / previous item",
    },
    HelpEntry {
        scope: "Library",
        key: "g / G",
        description: "Select first / last item",
    },
    HelpEntry {
        scope: "Library",
        key: "Ctrl-d / Ctrl-u",
        description: "Jump 15 items",
    },
    HelpEntry {
        scope: "Library",
        key: "h",
        description: "Go to parent folder",
    },
    HelpEntry {
        scope: "Library",
        key: "l",
        description: "Enter selected folder",
    },
    HelpEntry {
        scope: "Library",
        key: "s",
        description: "Mark/unmark selection",
    },
    HelpEntry {
        scope: "Library",
        key: "w",
        description: "Save selection as bookmark",
    },
    HelpEntry {
        scope: "Library",
        key: "W",
        description: "Download selection as capture (can take long; same name resumes)",
    },
    HelpEntry {
        scope: "Library",
        key: "%",
        description: "Create node here (e.g. search term)",
    },
    HelpEntry {
        scope: "Library",
        key: "e",
        description: "Rename selected node (e.g. search term)",
    },
    HelpEntry {
        scope: "Library",
        key: "d",
        description: "Delete selection (captures ask y/N, and delete files)",
    },
    HelpEntry {
        scope: "Library",
        key: "a",
        description: "Append selection to queue",
    },
    HelpEntry {
        scope: "Library",
        key: "L",
        description: "Queue selection after current track",
    },
    HelpEntry {
        scope: "Library",
        key: "Enter",
        description: "Replace queue with selection",
    },
    HelpEntry {
        scope: "Queue",
        key: "j / k",
        description: "Select next / previous track",
    },
    HelpEntry {
        scope: "Queue",
        key: "g / G",
        description: "Select first / last track",
    },
    HelpEntry {
        scope: "Queue",
        key: "Ctrl-d / Ctrl-u",
        description: "Jump 15 tracks",
    },
    HelpEntry {
        scope: "Queue",
        key: "o",
        description: "Select the playing track",
    },
    HelpEntry {
        scope: "Queue",
        key: "Enter",
        description: "Play selected track",
    },
    HelpEntry {
        scope: "Queue",
        key: "p",
        description: "Insert library selection after this track",
    },
    HelpEntry {
        scope: "Queue",
        key: "d",
        description: "Remove selected track",
    },
    HelpEntry {
        scope: "Queue",
        key: "c",
        description: "Clear queue except current track",
    },
    HelpEntry {
        scope: "Queue",
        key: "C",
        description: "Clear entire queue",
    },
    HelpEntry {
        scope: "Queue",
        key: "w",
        description: "Save queue under a name",
    },
    HelpEntry {
        scope: "Help",
        key: "Esc or ?",
        description: "Close help",
    },
];

/// Resolves a browser key event to an action, mirroring the TUI's
/// `bindings::lookup`: global chords first, then the focused pane's.
/// `key` is `KeyboardEvent.key` (case carries shift for letters);
/// `ctrl` is `ctrlKey`. While the help overlay is open only its close
/// keys resolve; dialogs bypass this entirely (they are modal).
pub fn lookup(focus: Focus, help_open: bool, key: &str, ctrl: bool) -> Option<Action> {
    if help_open {
        return matches!(key, "?" | "Escape" | "q").then_some(Action::CloseHelp);
    }
    if ctrl {
        return match key {
            "n" => Some(Action::NextTrack),
            "p" => Some(Action::PrevTrack),
            "d" => Some(match focus {
                Focus::Library => Action::LibraryJumpDown,
                Focus::Queue => Action::QueueJumpDown,
            }),
            "u" => Some(match focus {
                Focus::Library => Action::LibraryJumpUp,
                Focus::Queue => Action::QueueJumpUp,
            }),
            _ => None,
        };
    }
    let global = match key {
        "?" => Some(Action::OpenHelp),
        "Tab" => Some(Action::CycleFocus),
        " " => Some(Action::TogglePlay),
        "r" => Some(Action::RestartTrack),
        "K" => Some(Action::VolumeUp),
        "J" => Some(Action::VolumeDown),
        "m" => Some(Action::ToggleMute),
        "z" => Some(Action::ToggleShuffle),
        "x" => Some(Action::ToggleRepeat),
        _ => None,
    };
    if global.is_some() {
        return global;
    }
    match focus {
        Focus::Library => match key {
            "j" | "ArrowDown" => Some(Action::LibraryNext),
            "k" | "ArrowUp" => Some(Action::LibraryPrev),
            "g" => Some(Action::LibraryFirst),
            "G" => Some(Action::LibraryLast),
            "h" | "ArrowLeft" => Some(Action::LibraryAscend),
            "l" | "ArrowRight" => Some(Action::LibraryDive),
            "s" => Some(Action::LibraryToggleMark),
            "w" => Some(Action::LibraryCaptureNode),
            "W" => Some(Action::LibraryDownloadNode),
            "%" => Some(Action::LibraryCreateNode),
            "e" => Some(Action::LibraryEditNode),
            "d" => Some(Action::LibraryDeleteNode),
            "a" => Some(Action::LibraryQueueAppend),
            "L" => Some(Action::LibraryQueueNext),
            "Enter" => Some(Action::LibraryQueueReplace),
            _ => None,
        },
        Focus::Queue => match key {
            "j" | "ArrowDown" => Some(Action::QueueNext),
            "k" | "ArrowUp" => Some(Action::QueuePrev),
            "g" => Some(Action::QueueFirst),
            "G" => Some(Action::QueueLast),
            "o" => Some(Action::QueueSelectCurrent),
            "Enter" => Some(Action::QueuePlaySelected),
            "p" => Some(Action::QueueInsertHere),
            "d" => Some(Action::QueueRemoveTrack),
            "c" => Some(Action::QueueClearKeepCurrent),
            "C" => Some(Action::QueueClearAll),
            "w" => Some(Action::QueueSaveAs),
            _ => None,
        },
    }
}

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

    #[test]
    fn pane_focus_decides_shared_chords() {
        assert_eq!(
            lookup(Focus::Library, false, "d", false),
            Some(Action::LibraryDeleteNode)
        );
        assert_eq!(
            lookup(Focus::Queue, false, "d", false),
            Some(Action::QueueRemoveTrack)
        );
        assert_eq!(
            lookup(Focus::Library, false, "d", true),
            Some(Action::LibraryJumpDown)
        );
    }

    #[test]
    fn globals_win_in_both_panes() {
        for focus in [Focus::Library, Focus::Queue] {
            assert_eq!(lookup(focus, false, " ", false), Some(Action::TogglePlay));
            assert_eq!(
                lookup(focus, false, "z", false),
                Some(Action::ToggleShuffle)
            );
            assert_eq!(lookup(focus, false, "n", true), Some(Action::NextTrack));
        }
    }

    #[test]
    fn help_is_modal() {
        assert_eq!(lookup(Focus::Library, true, "j", false), None);
        assert_eq!(
            lookup(Focus::Library, true, "Escape", false),
            Some(Action::CloseHelp)
        );
        assert_eq!(
            lookup(Focus::Library, true, "?", false),
            Some(Action::CloseHelp)
        );
    }

    #[test]
    fn arrows_alias_the_vim_movement() {
        assert_eq!(
            lookup(Focus::Library, false, "ArrowDown", false),
            Some(Action::LibraryNext)
        );
        assert_eq!(
            lookup(Focus::Library, false, "ArrowLeft", false),
            Some(Action::LibraryAscend)
        );
        assert_eq!(
            lookup(Focus::Queue, false, "ArrowUp", false),
            Some(Action::QueuePrev)
        );
    }

    #[test]
    fn every_action_reachable_from_help_table() {
        // The help overlay documents at least every scope we bind.
        assert!(HELP.iter().any(|h| h.scope == "Global"));
        assert!(HELP.iter().any(|h| h.scope == "Library"));
        assert!(HELP.iter().any(|h| h.scope == "Queue"));
    }
}