#include <string.h>
#include "vis-core.h"
#include "util.h"

static Mode *mode_get(Vis *vis, enum VisMode mode) {
	if (mode < LENGTH(vis_modes))
		return &vis_modes[mode];
	return NULL;
}

void mode_set(Vis *vis, Mode *new_mode) {
	if (vis->mode == new_mode)
		return;
	if (vis->mode->leave)
		vis->mode->leave(vis, new_mode);
	if (vis->mode != &vis_modes[VIS_MODE_OPERATOR_PENDING])
		vis->mode_prev = vis->mode;
	vis->mode = new_mode;
	if (new_mode->enter)
		new_mode->enter(vis, vis->mode_prev);
	vis->win->ui->draw_status(vis->win->ui);
}

void vis_mode_switch(Vis *vis, enum VisMode mode) {
	mode_set(vis, &vis_modes[mode]);
}

static bool mode_map(Mode *mode, const char *key, const KeyBinding *binding) {
	if (!mode)
		return false;
	if (binding->alias && key[0] != '<' && strncmp(key, binding->alias, strlen(key)) == 0)
		return false;
	if (!mode->bindings) {
		mode->bindings = map_new();
		if (!mode->bindings)
			return false;
	}
	return (strcmp(key, "<") == 0 || !map_contains(mode->bindings, key)) && map_put(mode->bindings, key, binding);
}

bool vis_mode_map(Vis *vis, enum VisMode id, const char *key, const KeyBinding *binding) {
	return id < LENGTH(vis_modes) && mode_map(&vis_modes[id], key, binding);
}

bool vis_window_mode_map(Win *win, enum VisMode id, const char *key, const KeyBinding *binding) {
	return id < LENGTH(win->modes) && mode_map(&win->modes[id], key, binding);
}

static bool mode_unmap(Mode *mode, const char *key) {
	return mode && mode->bindings && map_delete(mode->bindings, key);
}

bool vis_mode_unmap(Vis *vis, enum VisMode id, const char *key) {
	return id < LENGTH(vis_modes) && mode_unmap(&vis_modes[id], key);
}

bool vis_window_mode_unmap(Win *win, enum VisMode id, const char *key) {
	return id < LENGTH(win->modes) && mode_unmap(&win->modes[id], key);
}

/** mode switching event handlers */

static void vis_mode_operator_input(Vis *vis, const char *str, size_t len) {
	/* invalid operator */
	vis_cancel(vis);
	mode_set(vis, vis->mode_prev);
}

static void vis_mode_visual_enter(Vis *vis, Mode *old) {
	if (!old->visual) {
		for (Cursor *c = view_cursors(vis->win->view); c; c = view_cursors_next(c))
			view_cursors_selection_start(c);
	}
}

static void vis_mode_visual_line_enter(Vis *vis, Mode *old) {
	if (!old->visual) {
		for (Cursor *c = view_cursors(vis->win->view); c; c = view_cursors_next(c))
			view_cursors_selection_start(c);
	}
	if (!vis->action.op)
		vis_motion(vis, VIS_MOVE_NOP);
}

static void vis_mode_visual_line_leave(Vis *vis, Mode *new) {
	if (!new->visual) {
		window_selection_save(vis->win);
		view_selections_clear(vis->win->view);
	} else {
		view_cursor_to(vis->win->view, view_cursor_get(vis->win->view));
	}
}

static void vis_mode_visual_leave(Vis *vis, Mode *new) {
	if (!new->visual) {
		window_selection_save(vis->win);
		view_selections_clear(vis->win->view);
	}
}

static void vis_mode_insert_enter(Vis *vis, Mode *old) {
	if (!vis->macro_operator) {
		macro_operator_record(vis);
		action_reset(&vis->action_prev);
		vis->action_prev.macro = vis->macro_operator;
		vis->action_prev.op = &vis_operators[VIS_OP_INSERT];
	}
}

static void vis_mode_insert_leave(Vis *vis, Mode *new) {
	/* make sure we can recover the current state after an editing operation */
	text_snapshot(vis->win->file->text);
	if (new == mode_get(vis, VIS_MODE_NORMAL))
		macro_operator_stop(vis);
}

static void vis_mode_insert_idle(Vis *vis) {
	text_snapshot(vis->win->file->text);
}

static void vis_mode_insert_input(Vis *vis, const char *str, size_t len) {
	vis_insert_key(vis, str, len);
}

static void vis_mode_replace_enter(Vis *vis, Mode *old) {
	if (!vis->macro_operator) {
		macro_operator_record(vis);
		action_reset(&vis->action_prev);
		vis->action_prev.macro = vis->macro_operator;
		vis->action_prev.op = &vis_operators[VIS_OP_REPLACE];
	}
}

static void vis_mode_replace_leave(Vis *vis, Mode *new) {
	/* make sure we can recover the current state after an editing operation */
	text_snapshot(vis->win->file->text);
	if (new == mode_get(vis, VIS_MODE_NORMAL))
		macro_operator_stop(vis);
}

static void vis_mode_replace_input(Vis *vis, const char *str, size_t len) {
	vis_replace_key(vis, str, len);
}

Mode vis_modes[] = {
	[VIS_MODE_OPERATOR_PENDING] = {
		.id = VIS_MODE_OPERATOR_PENDING,
		.name = "OPERATOR-PENDING",
		.input = vis_mode_operator_input,
		.help = "",
	},
	[VIS_MODE_NORMAL] = {
		.id = VIS_MODE_NORMAL,
		.name = "NORMAL",
		.status = "",
		.help = "",
	},
	[VIS_MODE_VISUAL] = {
		.id = VIS_MODE_VISUAL,
		.name = "VISUAL",
		.status = "--VISUAL--",
		.help = "",
		.enter = vis_mode_visual_enter,
		.leave = vis_mode_visual_leave,
		.visual = true,
	},
	[VIS_MODE_VISUAL_LINE] = {
		.id = VIS_MODE_VISUAL_LINE,
		.name = "VISUAL LINE",
		.parent = &vis_modes[VIS_MODE_VISUAL],
		.status = "--VISUAL LINE--",
		.help = "",
		.enter = vis_mode_visual_line_enter,
		.leave = vis_mode_visual_line_leave,
		.visual = true,
	},
	[VIS_MODE_INSERT] = {
		.id = VIS_MODE_INSERT,
		.name = "INSERT",
		.status = "--INSERT--",
		.help = "",
		.enter = vis_mode_insert_enter,
		.leave = vis_mode_insert_leave,
		.input = vis_mode_insert_input,
		.idle = vis_mode_insert_idle,
		.idle_timeout = 3,
	},
	[VIS_MODE_REPLACE] = {
		.id = VIS_MODE_REPLACE,
		.name = "REPLACE",
		.parent = &vis_modes[VIS_MODE_INSERT],
		.status = "--REPLACE--",
		.help = "",
		.enter = vis_mode_replace_enter,
		.leave = vis_mode_replace_leave,
		.input = vis_mode_replace_input,
		.idle = vis_mode_insert_idle,
		.idle_timeout = 3,
	},
};