local M = {}

M.version = "0.1"
M.name = "Legacy_View"
M.namespace = "nl_spacegirl_plugin_Default"

local BufferSearchOpen = false
local BufferSearchOpenElapsed = 0

local CommandSearchOpen = false
local CommandSearchOpenElapsed = 0
local CommandList = {}

local LogWindowOpen = false
local LogWindowOpenElapsed = 0

local CurrentPreviewBufferIndex = Editor.get_current_buffer_index()
local BufferSearchIndex = 0

local SideBarSmoothedWidth = 128
local SideBarWidth = 128
local SideBarClosed = false

local ActiveCodeView = nil
local CodeViews = {}

local MovingTab = nil
local MovingTabDest = nil
local MovingTabInBetween = false

local LastMouseX = 0
local LastMouseY = 0

function buffer_list_iter(start)
    local idx = start 
    return function ()
        buffer_info = Editor.buffer_info_from_index(idx)
        idx = idx + 1

        return buffer_info, idx-1
    end
end

function centered(ctx, label, axis, width, height, body)
    UI.push_parent(ctx, UI.push_rect(ctx, label, false, false, UI.Horizontal, UI.Fill, UI.Fill))
        UI.spacer(ctx, "left spacer")
        UI.push_parent(ctx, UI.push_rect(ctx, "halfway centered", false, false, UI.Vertical, width, UI.Fill))
            UI.spacer(ctx, "top spacer")
            UI.push_parent(ctx, UI.push_rect(ctx, "centered container", false, false, axis, UI.Fill, height))
                body()
            UI.pop_parent(ctx)
            UI.spacer(ctx, "bottom spacer")
        UI.pop_parent(ctx)
        UI.spacer(ctx, "right spacer")
    UI.pop_parent(ctx)
end

function list_iter(start, list)
    local idx = start 

    return function()
        local value = list[idx]
        idx = idx + 1
        return value, idx-1
    end
end

function list(ctx, label, selection_index, list, render_func)
    list_with_iter(ctx, label, selection_index, list_iter(selection_index, list), render_func)
end

function list_with_iter(ctx, label, selection_index, list_iter, render_func)
    local num_items = 10

    UI.push_parent(ctx, UI.push_rect(ctx, label, true, true, UI.Vertical, UI.Fill, UI.Fill))
        for data, i in list_iter do
            render_func(ctx, data, i == selection_index)
        end
    UI.pop_parent(ctx)
end

function lerp(from, to, rate)
    return (1 - rate) * from + rate*to
end

function remove_buffer_from_code_view(code_view_index, file_path)
    if code_view_index ~= nil and CodeViews[code_view_index] ~= nil then
        CodeViews[code_view_index].tabs[file_path] = nil
        k,v = pairs(CodeViews[code_view_index].tabs)(CodeViews[code_view_index].tabs)
        CodeViews[code_view_index].current_tab = k
    end
end

function add_buffer_to_code_view(code_view_index, file_path, buffer_index)
    if code_view_index == nil then
        code_view_index = 1
        ActiveCodeView = 1
    end

    -- A new code view is being created
    if CodeViews[code_view_index] == nil then
        CodeViews[code_view_index] = {}
        CodeViews[code_view_index].tabs = {}
        CodeViews[code_view_index].width = UI.Fill
    end

    ActiveCodeView = code_view_index

    CodeViews[code_view_index].tabs[file_path] = {}
    CodeViews[code_view_index].tabs[file_path].buffer_index = buffer_index
    CodeViews[code_view_index].current_tab = file_path
end

function ui_sidemenu(ctx)
    if SideBarClosed then
        SideBarSmoothedWidth = lerp(SideBarSmoothedWidth, 0, 0.3)
    else
        SideBarSmoothedWidth = lerp(SideBarSmoothedWidth, SideBarWidth, 0.3)
    end

    side_menu, _ = UI.push_box(ctx, "side menu", {"Scrollable"}, UI.Vertical, UI.Exact(SideBarSmoothedWidth), UI.Fill)
    UI.push_parent(ctx, side_menu)
        UI.push_rect(ctx, "padded top open files", false, false, UI.Horizontal, UI.Fill, UI.Exact(8))
        UI.push_parent(ctx, UI.push_rect(ctx, "padded open files", false, false, UI.Horizontal, UI.Fill, UI.ChildrenSum))
            UI.push_rect(ctx, "padded top open files", false, false, UI.Horizontal, UI.Exact(8), UI.Fill)
            UI.label(ctx, "Open Files")
        UI.pop_parent(ctx)
        UI.push_rect(ctx, "padded bottom open files", false, false, UI.Horizontal, UI.Fill, UI.Exact(8))

        for buffer_info, i in buffer_list_iter(0) do
            button_container = UI.push_rect(ctx, "button container"..i, false, false, UI.Horizontal, UI.Fill, UI.ChildrenSum)
            UI.push_parent(ctx, button_container)
                flags = {"Clickable", "Hoverable", "DrawText"}
                if i == current_buffer_index then
                    table.insert(flags, 1, "DrawBackground")
                end

                if UI.advanced_button(ctx, " x ", flags, UI.FitText, UI.FitText).clicked then
                    Editor.log("hahah, you can't close buffers yet silly")
                    if ActiveCodeView ~= nil then
                        Editor.set_current_buffer_from_index(i)
                        add_buffer_to_code_view(ActiveCodeView+1, buffer_info.file_path, i)
                    end
                end

                tab_button_interaction = UI.advanced_button(ctx, " "..buffer_info.file_path.." ", flags, UI.Fill, UI.FitText)
                if tab_button_interaction.clicked then
                    Editor.set_current_buffer_from_index(i)
                    add_buffer_to_code_view(ActiveCodeView, buffer_info.file_path, i)
                end
                if tab_button_interaction.hovering then
                    CurrentPreviewBufferIndex = i
                end
            UI.pop_parent(ctx)
        end
        UI.spacer(ctx, "below buffers spacer")

    UI.pop_parent(ctx)
end

function ui_code_view(ctx, code_view_index)
    local code_view = CodeViews[code_view_index]
    local is_tab_dest = MovingTab ~= nil and ActiveCodeView ~= code_view_index

    code_view_rect, code_view_interaction = UI.push_rect(ctx, code_view_index.." code view", ActiveCodeView ~= code_view_index, true, UI.Vertical, code_view.width, UI.Fill)

    UI.push_parent(ctx, code_view_rect)
        tab_dest_flags = {}
        if is_tab_dest then tab_dest_flags = {"Hoverable"} end

        tab_dest_region, tab_dest_interaction = UI.push_box(ctx, "code view tab dest", tab_dest_flags, UI.Vertical, UI.Fill, UI.Fill)
        UI.push_parent(ctx, tab_dest_region)
            if is_tab_dest then
                if tab_dest_interaction.hovering then
                    MovingTabDest = code_view_index
                elseif MovingTabDest == code_view_index then
                    MovingTabDest = nil
                end
            end

            UI.push_parent(ctx, UI.push_box(ctx, "tabs", {}, UI.Horizontal, UI.Fill, UI.ChildrenSum))
                for k,v in pairs(code_view.tabs) do
                    show_border = k ~= code_view.current_tab
                    background = show_border
                    flags = {"Clickable", "DrawText"}
                    if show_border then
                        table.insert(flags, 1, "DrawBorder")
                        table.insert(flags, 1, "Hoverable")
                    end

                    UI.push_parent(ctx, UI.push_rect(ctx, k.." tab container", background, false, UI.Horizontal, UI.ChildrenSum, UI.ChildrenSum))
                        tab_button = UI.advanced_button(ctx, " "..k.." ", flags, UI.FitText, UI.Exact(32))
                        if tab_button.clicked or tab_button.dragging then
                            ActiveCodeView = code_view_index
                            code_view.current_tab = k

                            Editor.set_current_buffer_from_index(v["buffer_index"])
                        end

                        if tab_button.dragging then
                            if MovingTab == nil then
                                MovingTab = {}
                                MovingTab["code_view_index"] = code_view_index
                                MovingTab["tab"] = k
                            end

                            UI.push_parent(ctx, UI.push_floating(ctx, "dragging tab", x-(96/2), y-(32/2)))
                                UI.advanced_button(ctx, " "..k.." ", {"DrawText", "DrawBorder", "DrawBackground"}, UI.FitText, UI.Exact(32))
                            UI.pop_parent(ctx)
                        elseif MovingTab ~= nil and MovingTab["code_view_index"] == code_view_index and MovingTab["tab"] == k then
                            if MovingTabDest ~= nil then
                                if MovingTabInBetween then
                                    remove_buffer_from_code_view(code_view_index, k)

                                    table.insert(CodeViews, MovingTabDest+1, nil)
                                    add_buffer_to_code_view(MovingTabDest+1, k, v["buffer_index"])
                                else
                                    add_buffer_to_code_view(MovingTabDest, k, v["buffer_index"])
                                    remove_buffer_from_code_view(code_view_index, k)

                                    MovingTabDest = nil
                                end
                            end

                            MovingTab = nil
                        end
                    UI.pop_parent(ctx)
                end
            UI.pop_parent(ctx)

            current_tab = code_view.current_tab
            if code_view.tabs[current_tab] ~= nil then
                buffer_index = code_view.tabs[current_tab].buffer_index

                UI.buffer(ctx, buffer_index)
            end

        UI.pop_parent(ctx)
    UI.pop_parent(ctx)

    return code_view_interaction
end

function M.render_ui_window(ctx)
    current_buffer_index = Editor.get_current_buffer_index()
    x,y = UI.get_mouse_pos(ctx)
    delta_x = LastMouseX - x
    delta_y = LastMouseY - y

    numFrames = 7
    CurrentPreviewBufferIndex = current_buffer_index

    if not SideBarClosed or SideBarSmoothedWidth > 2 then
        ui_sidemenu(ctx)
    end

    side_bar_interaction = UI.advanced_button(ctx, "side menu grab handle", {"DrawBorder", "Hoverable", "Clickable"}, UI.Exact(16), UI.Fill)
    if side_bar_interaction.clicked then
        if SideBarClosed then
            SideBarClosed = false

            if SideBarWidth < 32 then
                SideBarWidth = 128
            end
        else
            SideBarClosed = true
        end
    end
    if side_bar_interaction.dragging then
        SideBarWidth = x-8

        if SideBarWidth < 32 then
            SideBarClosed = true
            SideBarWidth = 0
        elseif SideBarWidth > 128 then
            SideBarClosed = false
        end

        if not SideBarClosed then
            SideBarWidth = math.max(SideBarWidth, 128)
        end
    end

    for k,v in ipairs(CodeViews) do
        code_view_interaction = ui_code_view(ctx, k)

        if next(CodeViews, k) ~= nil then
            interaction = UI.advanced_button(ctx, k.."code view grab handle", {"DrawBorder", "Hoverable", "Clickable"}, UI.Exact(16), UI.Fill)
            if interaction.dragging then
                local width = math.max(32, x - code_view_interaction.box_pos.x)
                v.width = UI.Exact(width)
            elseif interaction.clicked then
                v.width = UI.Fill
            elseif MovingTab ~= nil and interaction.hovering then
                MovingTabInBetween = true
                MovingTabDest = k
            elseif MovingTabDest == k and MovingTabInBetween then
                MovingTabInBetween = false
                MovingTabDest = nil
            end
        else
            v.width = UI.Fill
        end
    end

    for k,v in ipairs(CodeViews) do
        if next(v.tabs) == nil then
            table.remove(CodeViews, k)

            if ActiveCodeView > k then
                ActiveCodeView = ActiveCodeView - 1
            end
        end
    end

    -- render_buffer_search(ctx)
    render_command_search(ctx)
    render_log_window(ctx)

    LastMouseX = x
    LastMouseY = y
end

function M.open_buffer_search_window(ctx)
    -- if BufferSearchOpen or BufferSearchOpenElapsed > 0 then
    --     if BufferSearchOpen and BufferSearchOpenElapsed < numFrames then
    --         BufferSearchOpenElapsed = BufferSearchOpenElapsed + 1
    --     elseif not BufferSearchOpen and BufferSearchOpenElapsed > 0 then
    --         BufferSearchOpenElapsed = BufferSearchOpenElapsed - 1
    --     end
    -- end

    -- if BufferSearchOpen or BufferSearchOpenElapsed > 0 then
    --     window_percent = 75
    --     if BufferSearchOpenElapsed > 0 then
    --         window_percent = ((BufferSearchOpenElapsed/numFrames) * 75)
    --     end

    local input = {
        {Editor.Key.Escape, "Close Window", (
            function ()
                Editor.request_window_close()
                BufferSearchOpen = false
            end
        )},
        {Editor.Key.Enter, "Switch to Buffer", (
            function ()
                buffer_info = Editor.buffer_info_from_index(BufferSearchIndex)
                add_buffer_to_code_view(ActiveCodeView, buffer_info.file_path, BufferSearchIndex)

                Editor.set_current_buffer_from_index(BufferSearchIndex)
                Editor.request_window_close()
                BufferSearchOpen = false
            end
        )},
        -- TODO: don't scroll past buffers
        {Editor.Key.K, "Move Selection Up", (function () BufferSearchIndex = BufferSearchIndex - 1 end)},
        {Editor.Key.J, "Move Selection Down", (function () BufferSearchIndex = BufferSearchIndex + 1 end)},
    }

    Editor.spawn_floating_window(input, function(ctx)
        -- UI.push_parent(ctx, UI.push_floating(ctx, "buffer search canvas", 0, 0))
            -- centered(ctx, "buffer search window", UI.Horizontal, UI.PercentOfParent(window_percent), UI.PercentOfParent(window_percent), (
            --     function ()
                    list_with_iter(ctx, "buffer list", BufferSearchIndex, buffer_list_iter(BufferSearchIndex),
                        function(ctx, buffer_info, is_selected)
                            flags = {"DrawText"}

                            if is_selected then
                                table.insert(flags, 1, "DrawBorder")
                            end

                            interaction = UI.advanced_button(ctx, " "..buffer_info.file_path.." ", flags, UI.Fill, UI.FitText)
                        end
                    )
                    UI.buffer(ctx, BufferSearchIndex)

                    -- UI.push_parent(ctx, UI.push_rect(ctx, "window", true, true, UI.Horizontal, UI.Fill, UI.Fill))
                    --     UI.push_parent(ctx, UI.push_rect(ctx, "buffer list", false, false, UI.Vertical, UI.Fill, UI.Fill))
                    --         for buffer_info, i in buffer_list_iter() do
                    --             flags = {"DrawText"}
                    --
                    --             if i == BufferSearchIndex then
                    --                 table.insert(flags, 1, "DrawBorder")
                    --             end
                    --             interaction = UI.advanced_button(ctx, " "..buffer_info.file_path.." ", flags, UI.Fill, UI.FitText)
                    --         end
                    --     UI.pop_parent(ctx)
                    --     UI.buffer(ctx, BufferSearchIndex)
                    -- UI.pop_parent(ctx)
                -- end
            -- ))
        -- UI.pop_parent(ctx)
    end)
    -- end
end

function M.open_command_palette(ctx)
    -- if CommandSearchOpen or CommandSearchOpenElapsed > 0 then
    --     if CommandSearchOpen and CommandSearchOpenElapsed < numFrames then
    --         CommandSearchOpenElapsed = CommandSearchOpenElapsed + 1
    --     elseif not CommandSearchOpen and CommandSearchOpenElapsed > 0 then
    --         CommandSearchOpenElapsed = CommandSearchOpenElapsed - 1
    --     end
    -- end

    -- if CommandSearchOpen or CommandSearchOpenElapsed > 0 then
    --     window_percent_width = 75
    --     window_percent_height = 25
    --     if CommandSearchOpenElapsed > 0 then
    --         window_percent_width = ((CommandSearchOpenElapsed/numFrames) * 75)
    --         window_percent_height = ((CommandSearchOpenElapsed/numFrames) * 25)
    --     end

        -- UI.push_parent(ctx, UI.push_floating(ctx, "buffer search canvas", 0, 0))
        --     centered(ctx, "command search window", UI.Horizontal, UI.PercentOfParent(window_percent_width), UI.PercentOfParent(window_percent_height),
                -- function ()
    local input = {
        {Editor.Key.Escape, "Close Window", (
            function ()
                Editor.request_window_close()
                CommandSearchOpen = false
            end
        )},
        {Editor.Key.Enter, "Run Command", (
                function ()
                    if CommandList[CommandSearchIndex] ~= nil then 
                        Editor.run_command("nl.spacegirl.editor.core", CommandList[CommandSearchIndex]["name"])
                        CommandList = {}

                        Editor.request_window_close()
                        CommandSearchOpen = false
                    end
                end
        )},
        -- TODO: don't scroll past selections
        {Editor.Key.K, "Move Selection Up", (function () CommandSearchIndex = CommandSearchIndex - 1 end)},
        {Editor.Key.J, "Move Selection Down", (function () CommandSearchIndex = CommandSearchIndex + 1 end)},
    }

    Editor.spawn_floating_window(input, function(ctx)
        list(ctx, "command list", CommandSearchIndex, CommandList,
            function(ctx, cmd, is_selected)
                flags = {"DrawText"}

                if is_selected then
                    table.insert(flags, 1, "DrawBorder")
                end

                interaction = UI.advanced_button(ctx, " "..cmd.name..": "..cmd.description.." ", flags, UI.Fill, UI.FitText)
            end
        )
    end)
            -- )
    --     UI.pop_parent(ctx)
    -- end
end

function render_log_window(ctx)
    if Editor.get_current_buffer_index() ~= -2 then
        LogWindowOpen = false
    end

    if LogWindowOpen or LogWindowOpenElapsed > 0 then
        if LogWindowOpen and LogWindowOpenElapsed < numFrames then
            LogWindowOpenElapsed = LogWindowOpenElapsed + 1
        elseif not LogWindowOpen and LogWindowOpenElapsed > 0 then
            LogWindowOpenElapsed = LogWindowOpenElapsed - 1
        end
    end

    if LogWindowOpen or LogWindowOpenElapsed > 0 then
        window_percent = 75
        if LogWindowOpenElapsed > 0 then
            window_percent = ((LogWindowOpenElapsed/numFrames) * 75)
        end

        UI.push_parent(ctx, UI.push_floating(ctx, "log window canvas", 0, 0))
            centered(ctx, "log window", UI.Horizontal, UI.PercentOfParent(window_percent), UI.PercentOfParent(window_percent), (
                function ()
                    UI.push_parent(ctx, UI.push_rect(ctx, "window", true, true, UI.Horizontal, UI.Fill, UI.Fill))
                        -- -2 is the log buffer
                        UI.buffer(ctx, -2)
                    UI.pop_parent(ctx)
                end
            ))
        UI.pop_parent(ctx)
    end
end

function handle_buffer_input()
end

function M.OnLoad()
    Editor.log("Legacy View plugin loaded")

    Editor.register_key_group({
        {Editor.Key.Backtick, "Open Editor Logs", (function ()
            if not LogWindowOpen then
                LogWindowOpen = true 
                Editor.set_current_buffer_from_index(-2)
            else 
                LogWindowOpen = false
                local code_view = CodeViews[ActiveCodeView]
                Editor.set_current_buffer_from_index(code_view.tabs[code_view.current_tab]["buffer_index"])
            end
        end)},
        {Editor.Key.Space, "", {
            {Editor.Key.P, "Command Palette",
                (function ()
                    CommandSearchOpen = true
                    CommandSearchIndex = 1

                    CommandList = Editor.query_command_group("nl.spacegirl.editor.core")
                    M.open_command_palette()
                end),
            },
            {Editor.Key.B, "Buffer Search", M.open_buffer_search_window}
        }}
    })

    Editor.register_hook(Editor.Hook.OnDraw, render_ui_window)
    Editor.register_hook(Editor.Hook.OnBufferInput, handle_buffer_input)
end

return M