---@module "mez_types"

---@class Euclid
---@field default_config EuclidConfig
---@field config EuclidConfig
---@field state EuclidState
local M = {}

local utils = {}

---@param view_id integer
---@return integer? view_idx
---@return integer? tag_idx
utils.find_view = function (view_id)
	for tag_idx = 1, M.config.tag_count do
		for view_idx, v in ipairs(M.state.tags[tag_idx].views) do
			if v == view_id then
				return view_idx, tag_idx
			end
		end
	end

	return nil, nil
end

---@class EuclidConfig
---@field mod_key string
---@field tag_count number
---@field focus_on_spawn boolean
---@field refocus_on_kill boolean
local default_config = {
	mod_key = "alt",
	tag_count = 5,
	focus_on_spawn = true,
	refocus_on_kill = true,
}

---@class EuclidTag
---@field views number[]
---@field last_focused number | nil

---@class EuclidState
---@field tag_id number
---@field tags EuclidTag[]

---Add the id of a new view
---@param view_id number
M.add_view = function(view_id)
	local tag = M.state.tags[M.state.tag_id]

	tag.views[#tag.views + 1] = view_id

	local res = mez.output.get_available_area(0)
	if res == nil then return end
	mez.view.set_geometry(view_id, {
		x = (0.25 / 2) * res.width,
		y = (0.25 / 2) * res.height,
		width = res.width * 0.75,
		height = res.height * 0.75
	})

	if M.config.focus_on_spawn then mez.view.set_focused(view_id) end
end

---Move the focus in a tag to the next view
M.focus_next = function()
	local view_id = mez.view.get_focused_id()
	if view_id == nil then return end

	local view_idx, tag_idx = utils.find_view(view_id)
	if view_idx == nil or tag_idx == nil then return end

	local tag = M.state.tags[tag_idx]

	if view_idx == #tag.views then
		mez.view.set_focused(tag.views[1])
	else
		mez.view.set_focused(tag.views[view_idx + 1])
	end
end

---Move the focus in a tag to the previous view
M.focus_prev = function()
	local view_id = mez.view.get_focused_id()
	if view_id == nil then return end

	local view_idx, tag_idx = utils.find_view(view_id)
	if view_idx == nil or tag_idx == nil then return end

	local tag = M.state.tags[tag_idx]

	if view_idx == 1 then
		mez.view.set_focused(tag.views[#tag.views])
	else
		mez.view.set_focused(tag.views[view_idx - 1])
	end
end

---Remove a view_id from the layout
---@param view_id integer
M.remove_view = function(view_id)
	local view_idx, tag_idx = utils.find_view(view_id)
	if view_idx == nil or tag_idx == nil then return end
	local tag = M.state.tags[tag_idx]



	if M.config.refocus_on_kill then
		if #tag.views == 0 then
			mez.view.set_focused(nil)
		else
			mez.view.set_focused(tag.views[#tag.views == view_idx and view_idx - 1 or view_idx])
		end
	end
end

---Switch to a tag by enabling all views for 1 tag,
---and disabling all the views for the old tag
---@param tag_idx number
M.tag_enable = function (tag_idx)
	---@param t number
	---@param enabled boolean
	local set_tag_enable = function (t, enabled)
		local tag = M.state.tags[t]

		local focused = mez.view.get_focused_id()
		if not enabled and focused ~= nil then
			tag.last_focused = focused
		end

		for _, v in ipairs(tag.views) do
			mez.view.set_enabled(v, enabled)
		end
	end

	set_tag_enable(M.state.tag_id, false)
	set_tag_enable(tag_idx, true)

	M.state.tag_id = tag_idx
end

---@param view_id number
---@param tag_id number
M.send_view = function (view_id, tag_id)
	--  if view_id == 0 then view_id = mez.view.get_focused_id() end
	--  if tag_id == M.state.tag_id then return end
	--
	-- local type, _, _ = utils.find_view(view_id)
	--
	--  local tag = M.state.tags[tag_id]
	--
	--  M.remove_view(view_id)
	--
	--  if type == "floating" then
	--    table.insert(tag.floating, #tag.floating, view_id)
	--  else
	--    if tag.master == nil then
	--      tag.master = view_id
	--    else
	--      table.insert(tag.stack, #tag.stack, view_id)
	--    end
	--  end
	--
	--  mez.view.set_enabled(view_id, false)
	--  M.tile_tag(M.state.tag_id)
	--  M.tile_tag(tag_id)
end

M.setup = function()
	--- Take a user config
	M.config = default_config

	M.state = {
		tag_id = 1,
		tags = {},
	}

	-- Create all tags for the state
	for i = 1, M.config.tag_count do
		M.state.tags[i] = {
			views = {},
			last_focused = nil
		}
	end

	mez.hook.add("ViewMapPre", { callback = function(view_id) M.add_view(view_id) end })
	mez.hook.add("ViewUnmapPost", { callback = function(view_id) M.remove_view(view_id) end })

	mez.input.add_keymap(M.config.mod_key, "j", { press = function () M.focus_next() end })
	mez.input.add_keymap(M.config.mod_key, "k", { press = function () M.focus_prev() end })

	local fullscreen = function() mez.view.toggle_fullscreen(0) end
	mez.input.add_keymap(M.config.mod_key.."|shift", "F", { press = fullscreen })
	mez.hook.add("ViewRequestFullscreen", { callback = fullscreen })

	for i = 1, M.config.tag_count do
		mez.input.add_keymap(M.config.mod_key, tostring(i), { press = function () M.tag_enable(i) end })
	end

	mez.input.add_mousemap(M.config.mod_key, "BTN_LEFT", {
		press = function () return false end,
		drag = function(view_id, pos, _, offset)
			if view_id ~= nil then
				mez.view.set_geometry(view_id, { x = pos.x - offset.x, y = pos.y - offset.y })
			end

		end
	})

	---@type {x: number, y: number}[]
	local move_all = {}
	mez.input.add_mousemap(M.config.mod_key, "BTN_MIDDLE", {
		press = function ()
			move_all = {}
			for i, v in ipairs(M.state.tags[M.state.tag_id].views) do
				local geo = mez.view.get_geometry(v)
				move_all[i] = { x = geo.x, y = geo.y }
			end
		end,
		drag = function(_, pos, start, offset)
			for i, v in ipairs(M.state.tags[M.state.tag_id].views) do
				local geo = move_all[i]
				mez.view.set_geometry(v, {
					x = geo.x + (pos.x - start.x),
					y = geo.y + (pos.y - start.y)
				})
			end
		end
	})

	mez.input.add_mousemap(M.config.mod_key, "BTN_RIGHT", {
		drag = function(view_id, pos, start, offset)
			if view_id ~= nil then
				local geo = mez.view.get_geometry(view_id)

				local width = offset.x + pos.x - start.x
				local height = offset.y + pos.y - start.y

				if width <= 10 then width = 10 end
				if height <= 10 then height = 10 end
				mez.view.set_geometry(view_id, { width = width, height = height })
			end
		end
	})

	mez.input.add_mousemap(M.config.mod_key, "REL_WHEEL", {
		scroll = function (view_id, pos, delta, discrete_delta)
			delta = -delta / 250;
			mez.output.set_scale(0, mez.output.get_scale(0) + delta)
			print(mez.output.get_scale(0))
		end
	})

	mez.input.add_keymap(M.config.mod_key.."|shift", "equal", {
		press = function ()
			print("pressed")
			local _, err = pcall(function ()
				mez.output.set_scale(0, mez.output.get_scale(0) + 0.1)
				print(mez.output.get_scale(0))
			end)
			if err then
				print(err)
			end
		end
	})
end

return M