local vim = vim
local config = require('symbols-outline.config')
local symbol_kinds = require('symbols-outline.symbols').kinds
local M = {}

M.markers = {
    bottom = "└",
    middle = "├",
    vertical = "│",
    horizontal = "─"
}

M.hovered_hl_ns = vim.api.nvim_create_namespace("hovered_item")

function M.clear_hover_highlight(bufnr)
    vim.api.nvim_buf_clear_namespace(bufnr, M.hovered_hl_ns, 0, -1)
end

function M.add_hover_highlight(bufnr, line, col_start)
    vim.api.nvim_buf_add_highlight(bufnr, M.hovered_hl_ns, "FocusedSymbol",
                                   line, col_start, -1)
end

local function highlight_text(name, text, hl_group)
    vim.cmd(string.format("syn match %s /%s/", name, text))
    vim.cmd(string.format("hi def link %s %s", name, hl_group))
end

function M.setup_highlights()
    -- Setup the FocusedSymbol highlight group if it hasnt been done already by
    -- a theme or manually set
    if vim.fn.hlexists('FocusedSymbol') == 0 then
        vim.cmd 'hi FocusedSymbol term=italic,bold cterm=italic ctermbg=yellow ctermfg=darkblue gui=bold,italic guibg=yellow guifg=darkblue'
    end

    -- Some colorschemes do some funky things with the comment highlight, most
    -- notably making them italic, which messes up the outline connector. Fix
    -- this by copying the foreground color from the comment hl into a new
    -- highlight.
    local comment_fg_gui = vim.fn.synIDattr(vim.fn.synIDtrans(vim.fn.hlID('Comment')), 'fg', 'gui')
    local comment_fg_cterm = vim.fn.synIDattr(vim.fn.synIDtrans(vim.fn.hlID('Comment')), 'fg',
                                              'cterm')

    if vim.fn.hlexists('SymbolsOutlineConnector') == 0 then
        vim.cmd(string.format('hi SymbolsOutlineConnector ctermfg=%s guifg=%s',
                              comment_fg_cterm, comment_fg_gui))
    end

    local symbols = config.options.symbols

    -- markers
    highlight_text("marker_middle", M.markers.middle, "SymbolsOutlineConnector")
    highlight_text("marker_vertical", M.markers.vertical,
                   "SymbolsOutlineConnector")
    highlight_text("markers_horizontal", M.markers.horizontal,
                   "SymbolsOutlineConnector")
    highlight_text("markers_bottom", M.markers.bottom, "SymbolsOutlineConnector")

    for _, value in ipairs(symbol_kinds) do
        local symbol = symbols[value]
        highlight_text(value, symbol.icon, symbol.hl)
    end

end

return M