#include <wlc/wlc.h>

#include "focus.h"
#include "log.h"
#include "workspace.h"

bool locked_container_focus = false;
bool locked_view_focus = false;

// switches parent focus to c. will switch it accordingly
// TODO: Everything needs a handle, so we can set front/back position properly
static void update_focus(swayc_t *c) {
	// Handle if focus switches
	swayc_t *parent = c->parent;
	if (parent->focused != c) {
		switch (c->type) {
		// Shouldnt happen
		case C_ROOT: return;

		// Case where output changes
		case C_OUTPUT:
			wlc_output_focus(c->handle);
			break;

		// Case where workspace changes
		case C_WORKSPACE:
			if (parent->focused) {
				swayc_t *ws = parent->focused;
				// hide visibility of old workspace
				uint32_t mask = 1;
				container_map(ws, set_view_visibility, &mask);
				// set visibility of new workspace
				mask = 2;
				container_map(c, set_view_visibility, &mask);
				wlc_output_set_mask(parent->handle, 2);
				c->parent->focused = c;
				destroy_workspace(ws);
			}
			active_workspace = c;
			break;

		default:
		case C_VIEW:
		case C_CONTAINER:
			// TODO whatever to do when container changes
			// for example, stacked and tabbing change stuff.
			break;
		}
	}
	c->parent->focused = c;
}

bool move_focus(enum movement_direction direction) {
	if (locked_container_focus) {
		return false;
	}
	swayc_t *current = get_focused_container(&root_container);
	if (current->type == C_VIEW
		&& wlc_view_get_state(current->handle) & WLC_BIT_FULLSCREEN) {
		return false;
	}
	swayc_t *parent = current->parent;

	if (direction == MOVE_PARENT) {
		if (parent->type == C_OUTPUT) {
			sway_log(L_DEBUG, "Focus cannot move to parent");
			return false;
		} else {
			sway_log(L_DEBUG, "Moving focus from %p:%ld to %p:%ld",
				current, current->handle, parent, parent->handle);
			set_focused_container(parent);
			return true;
		}
	}

	while (true) {
		sway_log(L_DEBUG, "Moving focus away from %p", current);

		// Test if we can even make a difference here
		bool can_move = false;
		int diff = 0;
		if (direction == MOVE_LEFT || direction == MOVE_RIGHT) {
			if (parent->layout == L_HORIZ || parent->type == C_ROOT) {
				can_move = true;
				diff = direction == MOVE_LEFT ? -1 : 1;
			}
		} else {
			if (parent->layout == L_VERT) {
				can_move = true;
				diff = direction == MOVE_UP ? -1 : 1;
			}
		}
		sway_log(L_DEBUG, "Can move? %s", can_move ? "yes" : "no");
		if (can_move) {
			int i;
			for (i = 0; i < parent->children->length; ++i) {
				swayc_t *child = parent->children->items[i];
				if (child == current) {
					break;
				}
			}
			int desired = i + diff;
			sway_log(L_DEBUG, "Moving from %d to %d", i, desired);
			if (desired < 0 || desired >= parent->children->length) {
				can_move = false;
			} else {
				swayc_t *newview = parent->children->items[desired];
				set_focused_container(get_focused_view(newview));
				return true;
			}
		}
		if (!can_move) {
			sway_log(L_DEBUG, "Can't move at current level, moving up tree");
			current = parent;
			parent = parent->parent;
			if (!parent) {
				// Nothing we can do
				return false;
			}
		}
	}
}

swayc_t *get_focused_container(swayc_t *parent) {
	while (parent && !parent->is_focused) {
		parent = parent->focused;
	}
	// just incase
	if (parent == NULL) {
		sway_log(L_DEBUG, "get_focused_container unable to find container");
		return active_workspace;
	}
	return parent;
}

void set_focused_container(swayc_t *c) {
	if (locked_container_focus || !c) {
		return;
	}
	sway_log(L_DEBUG, "Setting focus to %p:%ld", c, c->handle);

	// Find previous focused view, and the new focused view, if they are the same return
	swayc_t *focused = get_focused_view(&root_container);
	swayc_t *workspace = active_workspace;

	// update container focus from here to root, making necessary changes along
	// the way
	swayc_t *p = c;
	while (p != &root_container) {
		update_focus(p);
		p = p->parent;
		p->is_focused = false;
	}

	// if the workspace is the same, and previous focus is fullscreen, dont
	// change focus
	if (workspace == active_workspace
		&& wlc_view_get_state(focused->handle) & WLC_BIT_FULLSCREEN) {
		return;
	}

	// get new focused view and set focus to it.
	p = get_focused_view(c);
	if (p->type == C_VIEW && !(wlc_view_get_type(p->handle) & WLC_BIT_POPUP)) {
		// unactivate previous focus
		if (focused->type == C_VIEW) {
			wlc_view_set_state(focused->handle, WLC_BIT_ACTIVATED, false);
		}
		// activate current focus
		if (p->type == C_VIEW) {
			wlc_view_set_state(p->handle, WLC_BIT_ACTIVATED, true);
			//set focus if view_focus is unlocked
			if (!locked_view_focus) {
				wlc_view_focus(p->handle);
			}
		}
	}
}

void set_focused_container_for(swayc_t *a, swayc_t *c) {
	if (locked_container_focus || !c) {
		return;
	}
	swayc_t *find = c;
	// Ensure that a is an ancestor of c
	while (find != a && (find = find->parent)) {
		if (find == &root_container) {
			return;
		}
	}
	// Check if we changing a parent container that will see chnage
	bool effective = true;
	while (find != &root_container) {
		if (find->parent->focused != find) {
			effective = false;
		}
		find = find->parent;
	}
	if (effective) {
		// Go to set_focused_container
		set_focused_container(c);
		return;
	}

	sway_log(L_DEBUG, "Setting focus for %p:%ld to %p:%ld",
		a, a->handle, c, c->handle);

	c->is_focused = true;
	swayc_t *p = c;
	while (p != a) {
		update_focus(p);
		p = p->parent;
		p->is_focused = false;
	}
}

swayc_t *get_focused_view(swayc_t *parent) {
	while (parent && parent->type != C_VIEW) {
		if (parent->type == C_WORKSPACE && parent->focused == NULL) {
			return parent;
		}
		parent = parent->focused;
	}
	if (parent == NULL) {
		return active_workspace;
	}
	return parent;
}