#include <stdbool.h>
#include <string.h>
#include <strings.h>
#include "sway/commands.h"
#include "sway/tree/arrange.h"
#include "sway/tree/container.h"
#include "sway/tree/workspace.h"
#include "log.h"

static enum sway_container_layout parse_layout_string(char *s) {
	if (strcasecmp(s, "splith") == 0) {
		return L_HORIZ;
	} else if (strcasecmp(s, "splitv") == 0) {
		return L_VERT;
	} else if (strcasecmp(s, "tabbed") == 0) {
		return L_TABBED;
	} else if (strcasecmp(s, "stacking") == 0) {
		return L_STACKED;
	}
	return L_NONE;
}

static const char* expected_syntax =
	"Expected 'layout default|tabbed|stacking|splitv|splith' or "
	"'layout toggle [split|all]' or "
	"'layout toggle [split|tabbed|stacking|splitv|splith] [split|tabbed|stacking|splitv|splith]...'";

static enum sway_container_layout get_layout_toggle(int argc, char **argv,
		enum sway_container_layout layout,
		enum sway_container_layout prev_split_layout) {
	// "layout toggle"
	if (argc == 0) {
		return layout == L_HORIZ ? L_VERT : L_HORIZ;
	}

	if (argc == 2) {
		// "layout toggle split" (same as "layout toggle")
		if (strcasecmp(argv[1], "split") == 0) {
			return layout == L_HORIZ ? L_VERT : L_HORIZ;
		}
		// "layout toggle all"
		if (strcasecmp(argv[1], "all") == 0) {
			return layout == L_HORIZ ? L_VERT :
				layout == L_VERT ? L_STACKED :
				layout == L_STACKED ? L_TABBED : L_HORIZ;
		}
		return L_NONE;
	}

	enum sway_container_layout parsed;
	int curr = 1;
	for (; curr < argc; curr++) {
		parsed = parse_layout_string(argv[curr]);
		if (parsed == layout || (strcmp(argv[curr], "split") == 0 &&
				 (layout == L_VERT || layout == L_HORIZ))) {
			break;
		}
	}
	for (int i = curr + 1; i != curr; ++i) {
		// cycle round to find next valid layout
		if (i >= argc) {
			i = 1;
		}
		parsed = parse_layout_string(argv[i]);
		if (parsed != L_NONE) {
			return parsed;
		}
		if (strcmp(argv[i], "split") == 0) {
			return layout == L_HORIZ ? L_VERT :
				layout == L_VERT ? L_HORIZ : prev_split_layout;
		}
		// invalid layout strings are silently ignored
	}
	return L_NONE;
}

static enum sway_container_layout get_layout(int argc, char **argv,
		enum sway_container_layout layout,
		enum sway_container_layout prev_split_layout) {
	// Check if assigned directly
	enum sway_container_layout parsed = parse_layout_string(argv[0]);
	if (parsed != L_NONE) {
		return parsed;
	}

	if (strcasecmp(argv[0], "default") == 0) {
		return prev_split_layout;
	}

	if (strcasecmp(argv[0], "toggle") == 0) {
		argc--; argv++;
		return get_layout_toggle(argc, argv, layout, prev_split_layout);
	}

	return L_NONE;
}

struct cmd_results *cmd_layout(int argc, char **argv) {
	struct cmd_results *error = NULL;
	if ((error = checkarg(argc, "layout", EXPECTED_MORE_THAN, 0))) {
		return error;
	}
	struct sway_container *container = config->handler_context.container;
	struct sway_workspace *workspace = config->handler_context.workspace;

	if (container && container_is_floating(container)) {
		return cmd_results_new(CMD_FAILURE, "layout",
				"Unable to change layout of floating windows");
	}

	// Typically we change the layout of the current container, but if the
	// current container is a view (it usually is) then we'll change the layout
	// of the parent instead, as it doesn't make sense for views to have layout.
	if (container && container->view) {
		container = container->parent;
	}

	// We could be working with a container OR a workspace. These are different
	// structures, so we set up pointers to they layouts so we can refer them in
	// an abstract way.
	enum sway_container_layout new_layout = L_NONE;
	enum sway_container_layout old_layout = L_NONE;
	if (container) {
		old_layout = container->layout;
		new_layout = get_layout(argc, argv,
				container->layout, container->prev_split_layout);
	} else {
		old_layout = workspace->layout;
		new_layout = get_layout(argc, argv,
				workspace->layout, workspace->prev_split_layout);
	}
	if (new_layout == L_NONE) {
		return cmd_results_new(CMD_INVALID, "layout", expected_syntax);
	}
	if (new_layout != old_layout) {
		if (container) {
			if (old_layout != L_TABBED && old_layout != L_STACKED) {
				container->prev_split_layout = old_layout;
			}
			container->layout = new_layout;
			container_update_representation(container);
			arrange_container(container);
		} else {
			if (old_layout != L_TABBED && old_layout != L_STACKED) {
				workspace->prev_split_layout = old_layout;
			}
			workspace->layout = new_layout;
			workspace_update_representation(workspace);
			arrange_workspace(workspace);
		}
	}

	return cmd_results_new(CMD_SUCCESS, NULL, NULL);
}