local wezterm = require "wezterm"

-- The filled in variant of the powerline ) symbol
local SOLID_RIGHT_SEP = require("utf8").char(0xe0b4)

local M = {}
M.setup = function(scheme)
    wezterm.on("format-tab-title", function(tab, tabs, _, _, hover, max_width)
        local text_fg
        if tab.is_active then
            text_fg = scheme.tab_bar.active_tab.fg_color
        else
            text_fg = scheme.tab_bar.inactive_tab.fg_color
        end
        local title = wezterm.truncate_right(tab.active_pane.title, max_width - 2)
        local colours = wezterm.color.gradient({
            colors = { scheme.tab_bar.active_tab.bg_color, scheme.tab_bar.new_tab.bg_color },
        }, #tabs + 1)
        local elements = {}
        table.insert(elements, "ResetAttributes")
        table.insert(elements, { Background = { Color = colours[tab.tab_index + 1] } })
        table.insert(elements, { Foreground = { Color = text_fg } })
        table.insert(elements, { Text = " " })
        if tab.is_active then
            table.insert(elements, { Attribute = { Underline = "Single" } })
            table.insert(elements, { Attribute = { Intensity = "Bold" } })
        end
        if hover then table.insert(elements, { Attribute = { Italic = true } }) end
        table.insert(elements, { Text = title })
        table.insert(elements, "ResetAttributes")
        table.insert(elements, { Background = { Color = colours[tab.tab_index + 2] } })
        table.insert(elements, { Foreground = { Color = colours[tab.tab_index + 1] } })
        table.insert(elements, { Text = SOLID_RIGHT_SEP })
        table.insert(elements, "ResetAttributes")
        return elements
    end)
end

M._new_tab_format = function(scheme)
    return {
        { Background = { Color = scheme.tab_bar.new_tab.bg_color } },
        { Foreground = { Color = scheme.tab_bar.new_tab.fg_color } },
        { Text = " +" },
        "ResetAttributes",
        { Background = { Color = scheme.tab_bar.background } },
        { Foreground = { Color = scheme.tab_bar.new_tab.bg_color } },
        { Text = SOLID_RIGHT_SEP },
        "ResetAttributes",
    }
end

M.new_tab = function(scheme) return wezterm.format(M._new_tab_format(scheme)) end

M.new_tab_hover = function(scheme)
    local format = M._new_tab_format(scheme)
    table.insert(format, 1, { Attribute = { Italic = true } })
    return wezterm.format(format)
end

return M