local config = require('skift.config')
local cache = require("skift.utils.cache")

local M = {}

local function apply_highlights(highlights)
    for name, val in pairs(highlights) do
        if type(val) == 'string' then
            val = { link = val }
        end
        vim.api.nvim_set_hl(0, name, val)
    end
end

local function apply_terminal_colors(c)
    vim.g.terminal_color_0 = c.terminal_black
    vim.g.terminal_color_1 = c.terminal_red
    vim.g.terminal_color_2 = c.terminal_green
    vim.g.terminal_color_3 = c.terminal_yellow
    vim.g.terminal_color_4 = c.terminal_blue
    vim.g.terminal_color_5 = c.terminal_magenta
    vim.g.terminal_color_6 = c.terminal_cyan
    vim.g.terminal_color_7 = c.terminal_white
    vim.g.terminal_color_8 = c.terminal_bright_black
    vim.g.terminal_color_9 = c.terminal_bright_red
    vim.g.terminal_color_10 = c.terminal_bright_green
    vim.g.terminal_color_11 = c.terminal_bright_yellow
    vim.g.terminal_color_12 = c.terminal_bright_blue
    vim.g.terminal_color_13 = c.terminal_bright_magenta
    vim.g.terminal_color_14 = c.terminal_bright_cyan
    vim.g.terminal_color_15 = c.terminal_bright_white
end

function M.setup(opts)
    config:merge(opts)
end

function M.load()
    if vim.g.colors_name then
        vim.cmd("hi clear")
    end
    vim.g.colors_name = "skift"
    vim.o.termguicolors = true
    vim.o.background = "dark"

    local cache_key = cache.key(config)
    local cached = cache.read(cache_key)
    if cached and cached.highlights and cached.colors then
        apply_highlights(cached.highlights)
        apply_terminal_colors(cached.colors)
        return
    end

    local c = vim.deepcopy(require("skift.colors"))

    config.on_colors(c)

    local highlights = {}
    local groups = {
        require("skift.groups.editor").get(c),
        require("skift.groups.syntax").get(c),
        require("skift.groups.treesitter").get(c),
        require("skift.groups.lsp").get(c),
        require("skift.groups.integrations").get(c),
    }

    for _, group in ipairs(groups) do
        highlights = vim.tbl_extend("force", highlights, group)
    end

    if config.transparent then
        local transparent_groups = {
            "Normal", "NormalNC", "NormalFloat", "SignColumn",
            "FoldColumn", "TabLineFill", "StatusLine", "StatusLineNC",
            "NvimTreeNormal", "NeoTreeNormal", "NeoTreeNormalNC",
            "TreesitterContext",
        }
        for _, name in ipairs(transparent_groups) do
            if highlights[name] then
                highlights[name].bg = "NONE"
            end
        end
        highlights.WinSeparator = { fg = "NONE" }
        highlights.VertSplit = { fg = "NONE" }
        highlights.FloatBorder = { fg = "NONE", bg = "NONE" }
    end

    if not config.bold then
        for _, hl in pairs(highlights) do
            hl.bold = false
        end
    end

    if not config.italic then
        for _, hl in pairs(highlights) do
            hl.italic = false
        end
    elseif not config.italic_comments then
        for _, name in ipairs({ "Comment", "@comment", "@comment.documentation" }) do
            if highlights[name] then
                highlights[name].italic = false
            end
        end
    end

    config.on_highlights(highlights, c)

    apply_highlights(highlights)
    apply_terminal_colors(c)

    cache.write(cache_key, {
        highlights = highlights,
        colors = {
            terminal_black = c.terminal_black,
            terminal_red = c.terminal_red,
            terminal_green = c.terminal_green,
            terminal_yellow = c.terminal_yellow,
            terminal_blue = c.terminal_blue,
            terminal_magenta = c.terminal_magenta,
            terminal_cyan = c.terminal_cyan,
            terminal_white = c.terminal_white,
            terminal_bright_black = c.terminal_bright_black,
            terminal_bright_red = c.terminal_bright_red,
            terminal_bright_green = c.terminal_bright_green,
            terminal_bright_yellow = c.terminal_bright_yellow,
            terminal_bright_blue = c.terminal_bright_blue,
            terminal_bright_magenta = c.terminal_bright_magenta,
            terminal_bright_cyan = c.terminal_bright_cyan,
            terminal_bright_white = c.terminal_bright_white,
        },
    })
end

function M.clear_cache()
    cache.clear()
end

return M