const tp = @import("thespian");
const root = @import("root");

const key = @import("renderer").input.key;
const mod = @import("renderer").input.modifier;
const event_type = @import("renderer").input.event_type;
const ucs32_to_utf8 = @import("renderer").ucs32_to_utf8;

const tui = @import("../../tui.zig");
const command = @import("../../command.zig");
const EventHandler = @import("../../EventHandler.zig");

const Allocator = @import("std").mem.Allocator;
const ArrayList = @import("std").ArrayList;
const json = @import("std").json;
const eql = @import("std").mem.eql;

const Self = @This();
const input_buffer_size = 1024;

a: Allocator,
input: ArrayList(u8),
last_cmd: []const u8 = "",
leader: ?struct { keypress: u32, modifiers: u32 } = null,

pub fn create(a: Allocator) !tui.Mode {
    const self: *Self = try a.create(Self);
    self.* = .{
        .a = a,
        .input = try ArrayList(u8).initCapacity(a, input_buffer_size),
    };
    return .{
        .handler = EventHandler.to_owned(self),
        .name = root.application_logo ++ root.application_name,
        .description = "default",
        .keybind_hints = &hints,
    };
}

pub fn deinit(self: *Self) void {
    self.input.deinit();
    self.a.destroy(self);
}

pub fn receive(self: *Self, _: tp.pid_ref, m: tp.message) error{Exit}!bool {
    var evtype: u32 = undefined;
    var keypress: u32 = undefined;
    var egc: u32 = undefined;
    var modifiers: u32 = undefined;
    var text: []const u8 = undefined;

    if (try m.match(.{ "I", tp.extract(&evtype), tp.extract(&keypress), tp.extract(&egc), tp.string, tp.extract(&modifiers) })) {
        try self.mapEvent(evtype, keypress, egc, modifiers);
    } else if (try m.match(.{"F"})) {
        try self.flush_input();
    } else if (try m.match(.{ "system_clipboard", tp.extract(&text) })) {
        try self.paste_bytes(text);
    }
    return false;
}

pub fn add_keybind() void {}

fn mapEvent(self: *Self, evtype: u32, keypress: u32, egc: u32, modifiers: u32) tp.result {
    return switch (evtype) {
        event_type.PRESS => self.mapPress(keypress, egc, modifiers),
        event_type.REPEAT => self.mapPress(keypress, egc, modifiers),
        event_type.RELEASE => self.mapRelease(keypress, egc, modifiers),
        else => {},
    };
}

fn mapPress(self: *Self, keypress: u32, egc: u32, modifiers: u32) tp.result {
    const keynormal = if ('a' <= keypress and keypress <= 'z') keypress - ('a' - 'A') else keypress;
    if (self.leader) |_| return self.mapFollower(keynormal, egc, modifiers);
    switch (keypress) {
        key.LCTRL, key.RCTRL => return self.cmd("enable_fast_scroll", .{}),
        key.LALT, key.RALT => return self.cmd("enable_jump_mode", .{}),
        else => {},
    }
    return switch (modifiers) {
        mod.CTRL => switch (keynormal) {
            'E' => self.cmd("open_recent", .{}),
            'J' => self.cmd("toggle_logview", .{}),
            'Z' => self.cmd("undo", .{}),
            'Y' => self.cmd("redo", .{}),
            'Q' => self.cmd("quit", .{}),
            'O' => self.cmd("enter_open_file_mode", .{}),
            'W' => self.cmd("close_file", .{}),
            'S' => self.cmd("save_file", .{}),
            'L' => self.cmd_cycle3("scroll_view_center", "scroll_view_top", "scroll_view_bottom", .{}),
            'N' => self.cmd("goto_next_match", .{}),
            'P' => self.cmd("goto_prev_match", .{}),
            'B' => self.cmd("enter_move_to_char_mode", command.fmt(.{false})),
            'T' => self.cmd("enter_move_to_char_mode", command.fmt(.{true})),
            'X' => self.cmd("cut", .{}),
            'C' => self.cmd("copy", .{}),
            'V' => self.cmd("system_paste", .{}),
            'U' => self.cmd("pop_cursor", .{}),
            'K' => self.leader = .{ .keypress = keynormal, .modifiers = modifiers },
            'F' => self.cmd("enter_find_mode", .{}),
            'G' => self.cmd("enter_goto_mode", .{}),
            'D' => self.cmd("add_cursor_next_match", .{}),
            'A' => self.cmd("select_all", .{}),
            'I' => self.insert_bytes("\t"),
            '/' => self.cmd("toggle_comment", .{}),
            key.ENTER => self.cmd("smart_insert_line_after", .{}),
            key.SPACE => self.cmd("selections_reverse", .{}),
            key.END => self.cmd("move_buffer_end", .{}),
            key.HOME => self.cmd("move_buffer_begin", .{}),
            key.UP => self.cmd("move_scroll_up", .{}),
            key.DOWN => self.cmd("move_scroll_down", .{}),
            key.PGUP => self.cmd("move_scroll_page_up", .{}),
            key.PGDOWN => self.cmd("move_scroll_page_down", .{}),
            key.LEFT => self.cmd("move_word_left", .{}),
            key.RIGHT => self.cmd("move_word_right", .{}),
            key.BACKSPACE => self.cmd("delete_word_left", .{}),
            key.DEL => self.cmd("delete_word_right", .{}),
            key.F05 => self.cmd("toggle_inspector_view", .{}),
            key.F10 => self.cmd("toggle_whitespace", .{}), // aka F34
            else => {},
        },
        mod.CTRL | mod.SHIFT => switch (keynormal) {
            'P' => self.cmd("open_command_palette", .{}),
            'D' => self.cmd("dupe_down", .{}),
            'Z' => self.cmd("redo", .{}),
            'Q' => self.cmd("quit_without_saving", .{}),
            'W' => self.cmd("close_file_without_saving", .{}),
            'R' => self.cmd("restart", .{}),
            'F' => self.cmd("enter_find_in_files_mode", .{}),
            'L' => self.cmd_async("add_cursor_all_matches"),
            'I' => self.cmd_async("toggle_inspector_view"),
            key.ENTER => self.cmd("smart_insert_line_before", .{}),
            key.END => self.cmd("select_buffer_end", .{}),
            key.HOME => self.cmd("select_buffer_begin", .{}),
            key.UP => self.cmd("select_scroll_up", .{}),
            key.DOWN => self.cmd("select_scroll_down", .{}),
            key.LEFT => self.cmd("select_word_left", .{}),
            key.RIGHT => self.cmd("select_word_right", .{}),
            else => {},
        },
        mod.ALT => switch (keynormal) {
            'J' => self.cmd("join_next_line", .{}),
            'N' => self.cmd("goto_next_diagnostic", .{}),
            'P' => self.cmd("goto_prev_diagnostic", .{}),
            'U' => self.cmd("to_upper", .{}),
            'L' => self.cmd("to_lower", .{}),
            'I' => self.cmd("toggle_inputview", .{}),
            'B' => self.cmd("move_word_left", .{}),
            'F' => self.cmd("move_word_right", .{}),
            'S' => self.cmd("filter", command.fmt(.{"sort"})),
            'V' => self.cmd("paste", .{}),
            key.LEFT => self.cmd("jump_back", .{}),
            key.RIGHT => self.cmd("jump_forward", .{}),
            key.UP => self.cmd("pull_up", .{}),
            key.DOWN => self.cmd("pull_down", .{}),
            key.ENTER => self.cmd("insert_line", .{}),
            key.F10 => self.cmd("gutter_mode_next", .{}), // aka F58
            else => {},
        },
        mod.ALT | mod.SHIFT => switch (keynormal) {
            'P' => self.cmd("open_command_palette", .{}),
            'D' => self.cmd("dupe_up", .{}),
            // 'B' => self.cmd("select_word_left", .{}),
            // 'F' => self.cmd("select_word_right", .{}),
            'F' => self.cmd("format", .{}),
            'S' => self.cmd("filter", command.fmt(.{ "sort", "-u" })),
            'V' => self.cmd("paste", .{}),
            'I' => self.cmd("add_cursors_to_line_ends", .{}),
            key.LEFT => self.cmd("move_scroll_left", .{}),
            key.RIGHT => self.cmd("move_scroll_right", .{}),
            key.UP => self.cmd("add_cursor_up", .{}),
            key.DOWN => self.cmd("add_cursor_down", .{}),
            else => {},
        },
        mod.SHIFT => switch (keypress) {
            key.F03 => self.cmd("goto_prev_match", .{}),
            key.LEFT => self.cmd("select_left", .{}),
            key.RIGHT => self.cmd("select_right", .{}),
            key.UP => self.cmd("select_up", .{}),
            key.DOWN => self.cmd("select_down", .{}),
            key.HOME => self.cmd("smart_select_begin", .{}),
            key.END => self.cmd("select_end", .{}),
            key.PGUP => self.cmd("select_page_up", .{}),
            key.PGDOWN => self.cmd("select_page_down", .{}),
            key.ENTER => self.cmd("smart_insert_line_before", .{}),
            key.BACKSPACE => self.cmd("delete_backward", .{}),
            key.TAB => self.cmd("unindent", .{}),
            else => if (!key.synthesized_p(keypress))
                self.insert_code_point(egc)
            else {},
        },
        0 => switch (keypress) {
            key.F02 => self.cmd("toggle_input_mode", .{}),
            key.F03 => self.cmd("goto_next_match", .{}),
            key.F15 => self.cmd("goto_prev_match", .{}), // S-F3
            key.F05 => self.cmd("toggle_inspector_view", .{}), // C-F5
            key.F06 => self.cmd("dump_current_line_tree", .{}),
            key.F07 => self.cmd("dump_current_line", .{}),
            key.F09 => self.cmd("theme_prev", .{}),
            key.F10 => self.cmd("theme_next", .{}),
            key.F11 => self.cmd("toggle_logview", .{}),
            key.F12 => self.cmd("goto_definition", .{}),
            key.F34 => self.cmd("toggle_whitespace", .{}), // C-F10
            key.F58 => self.cmd("gutter_mode_next", .{}), // A-F10
            key.ESC => self.cmd("cancel", .{}),
            key.ENTER => self.cmd("smart_insert_line", .{}),
            key.DEL => self.cmd("delete_forward", .{}),
            key.BACKSPACE => self.cmd("delete_backward", .{}),
            key.LEFT => self.cmd("move_left", .{}),
            key.RIGHT => self.cmd("move_right", .{}),
            key.UP => self.cmd("move_up", .{}),
            key.DOWN => self.cmd("move_down", .{}),
            key.HOME => self.cmd("smart_move_begin", .{}),
            key.END => self.cmd("move_end", .{}),
            key.PGUP => self.cmd("move_page_up", .{}),
            key.PGDOWN => self.cmd("move_page_down", .{}),
            key.TAB => self.cmd("indent", .{}),
            else => if (!key.synthesized_p(keypress))
                self.insert_code_point(egc)
            else {},
        },
        else => {},
    };
}

fn mapFollower(self: *Self, keypress: u32, _: u32, modifiers: u32) tp.result {
    defer self.leader = null;
    const ldr = if (self.leader) |leader| leader else return;
    return switch (ldr.modifiers) {
        mod.CTRL => switch (ldr.keypress) {
            'K' => switch (modifiers) {
                mod.CTRL => switch (keypress) {
                    'U' => self.cmd("delete_to_begin", .{}),
                    'K' => self.cmd("delete_to_end", .{}),
                    'D' => self.cmd("move_cursor_next_match", .{}),
                    else => {},
                },
                else => {},
            },
            else => {},
        },
        else => {},
    };
}

fn mapRelease(self: *Self, keypress: u32, _: u32, _: u32) tp.result {
    return switch (keypress) {
        key.LCTRL, key.RCTRL => self.cmd("disable_fast_scroll", .{}),
        key.LALT, key.RALT => self.cmd("disable_jump_mode", .{}),
        else => {},
    };
}

fn insert_code_point(self: *Self, c: u32) tp.result {
    if (self.input.items.len + 4 > input_buffer_size)
        try self.flush_input();
    var buf: [6]u8 = undefined;
    const bytes = ucs32_to_utf8(&[_]u32{c}, &buf) catch |e| return tp.exit_error(e);
    self.input.appendSlice(buf[0..bytes]) catch |e| return tp.exit_error(e);
}

fn insert_bytes(self: *Self, bytes: []const u8) tp.result {
    if (self.input.items.len + 4 > input_buffer_size)
        try self.flush_input();
    self.input.appendSlice(bytes) catch |e| return tp.exit_error(e);
}

fn paste_bytes(self: *Self, bytes: []const u8) tp.result {
    try self.flush_input();
    try command.executeName("paste", command.fmt(.{bytes}));
}

var insert_chars_id: ?command.ID = null;

fn flush_input(self: *Self) tp.result {
    if (self.input.items.len > 0) {
        defer self.input.clearRetainingCapacity();
        const id = insert_chars_id orelse command.get_id_cache("insert_chars", &insert_chars_id) orelse {
            return tp.exit_error(error.InputTargetNotFound);
        };
        try command.execute(id, command.fmt(.{self.input.items}));
        self.last_cmd = "insert_chars";
    }
}

fn cmd(self: *Self, name_: []const u8, ctx: command.Context) tp.result {
    try self.flush_input();
    self.last_cmd = name_;
    try command.executeName(name_, ctx);
}

fn cmd_cycle3(self: *Self, name1: []const u8, name2: []const u8, name3: []const u8, ctx: command.Context) tp.result {
    return if (eql(u8, self.last_cmd, name2))
        self.cmd(name3, ctx)
    else if (eql(u8, self.last_cmd, name1))
        self.cmd(name2, ctx)
    else
        self.cmd(name1, ctx);
}

fn cmd_async(self: *Self, name_: []const u8) tp.result {
    self.last_cmd = name_;
    return tp.self_pid().send(.{ "cmd", name_ });
}

const hints = tui.KeybindHints.initComptime(.{
    .{ "add_cursor_all_matches", "C-S-l" },
    .{ "add_cursor_down", "S-A-down" },
    .{ "add_cursor_next_match", "C-d" },
    .{ "add_cursors_to_line_ends", "S-A-i" },
    .{ "add_cursor_up", "S-A-up" },
    .{ "cancel", "esc" },
    .{ "close_file", "C-w" },
    .{ "close_file_without_saving", "C-S-w" },
    .{ "copy", "C-c" },
    .{ "cut", "C-x" },
    .{ "delete_backward", "backspace" },
    .{ "delete_forward", "del" },
    .{ "delete_to_begin", "C-k C-u" },
    .{ "delete_to_end", "C-k C-k" },
    .{ "delete_word_left", "C-backspace" },
    .{ "delete_word_right", "C-del" },
    .{ "dump_current_line", "F7" },
    .{ "dump_current_line_tree", "F6" },
    .{ "dupe_down", "C-S-d" },
    .{ "dupe_up", "S-A-d" },
    .{ "enable_fast_scroll", "hold Ctrl" },
    .{ "enable_jump_mode", "hold Alt" },
    .{ "enter_find_in_files_mode", "C-S-f" },
    .{ "enter_find_mode", "C-f" },
    .{ "enter_goto_mode", "C-g" },
    .{ "enter_move_to_char_mode", "C-b, C-t" }, // true/false
    .{ "enter_open_file_mode", "C-o" },
    .{ "filter", "A-s" }, // self.cmd("filter", command.fmt(.{"sort"})),
    // .{ "filter", "S-A-s" }, // self.cmd("filter", command.fmt(.{ "sort", "-u" })),
    .{ "format", "S-A-f" },
    .{ "goto_definition", "F12" },
    .{ "goto_next_diagnostic", "A-n" },
    .{ "goto_next_match", "C-n, F3" },
    .{ "goto_prev_diagnostic", "A-p" },
    .{ "goto_prev_match", "C-p, S-F3" },
    .{ "gutter_mode_next", "A-F10" },
    .{ "indent", "tab" },
    .{ "insert_line", "A-enter" },
    .{ "join_next_line", "A-j" },
    .{ "jump_back", "A-left" },
    .{ "jump_forward", "A-right" },
    .{ "move_buffer_begin", "C-home" },
    .{ "move_buffer_end", "C-end" },
    .{ "move_cursor_next_match", "C-k C-d" },
    .{ "move_down", "down" },
    .{ "move_end", "end" },
    .{ "move_left", "left" },
    .{ "move_page_down", "pgdn" },
    .{ "move_page_up", "pgup" },
    .{ "move_right", "right" },
    .{ "move_scroll_down", "C-down" },
    .{ "move_scroll_left", "S-A-left" },
    .{ "move_scroll_page_down", "C-pgdn" },
    .{ "move_scroll_page_up", "C-pgup" },
    .{ "move_scroll_right", "S-A-right" },
    .{ "move_scroll_up", "C-up" },
    .{ "move_up", "up" },
    .{ "move_word_left", "C-left, A-b" },
    .{ "move_word_right", "C-right, A-f" },
    .{ "open_command_palette", "C-S-p, S-A-p" },
    .{ "open_recent", "C-e" },
    .{ "paste", "A-v" },
    .{ "pop_cursor", "C-u" },
    .{ "pull_down", "A-down" },
    .{ "pull_up", "A-up" },
    .{ "quit", "C-q" },
    .{ "quit_without_saving", "C-S-q" },
    .{ "redo", "C-S-z, C-y" },
    .{ "restart", "C-S-r" },
    .{ "save_file", "C-s" },
    .{ "scroll_view_bottom", "C-l" },
    .{ "scroll_view_center", "C-l" },
    .{ "scroll_view_top", "C-l" },
    .{ "select_all", "C-a" },
    .{ "select_buffer_begin", "C-S-home" },
    .{ "select_buffer_end", "C-S-end" },
    .{ "select_down", "S-down" },
    .{ "select_end", "S-end" },
    .{ "selections_reverse", "C-space" },
    .{ "select_left", "S-left" },
    .{ "select_page_down", "S-pgdn" },
    .{ "select_page_up", "S-pgup" },
    .{ "select_right", "S-right" },
    .{ "select_scroll_down", "C-S-down" },
    .{ "select_scroll_up", "C-S-up" },
    .{ "select_up", "S-up" },
    .{ "select_word_left", "C-S-left" },
    .{ "select_word_right", "C-S-right" },
    .{ "smart_insert_line_after", "C-enter" },
    .{ "smart_insert_line_before", "S-enter, C-S-enter" },
    .{ "smart_insert_line", "enter" },
    .{ "smart_move_begin", "home" },
    .{ "smart_select_begin", "S-home" },
    .{ "system_paste", "C-v" },
    .{ "theme_next", "F10" },
    .{ "theme_prev", "F9" },
    .{ "toggle_comment", "C-/" },
    .{ "toggle_input_mode", "F2" },
    .{ "toggle_inputview", "A-i" },
    .{ "toggle_inspector_view", "F5, C-F5, C-S-i" },
    .{ "toggle_logview", "C-j, F11" },
    .{ "toggle_whitespace", "C-F10" },
    .{ "to_lower", "A-l" },
    .{ "to_upper", "A-u" },
    .{ "undo", "C-z" },
    .{ "unindent", "S-tab" },
});