-- Symbol usage plugin

local SymbolKind = vim.lsp.protocol.SymbolKind

local function h(name)
    return vim.api.nvim_get_hl(0, { name = name })
end

-- hl-groups can have any name
vim.api.nvim_set_hl(0, 'SymbolUsageRounding', { fg = h('CursorLine').bg, italic = true })
vim.api.nvim_set_hl(0, 'SymbolUsageContent', { bg = h('CursorLine').bg, fg = h('Comment').fg, italic = true })
vim.api.nvim_set_hl(0, 'SymbolUsageRef', { fg = h('Function').fg, bg = h('CursorLine').bg, italic = true })
vim.api.nvim_set_hl(0, 'SymbolUsageDef', { fg = h('Type').fg, bg = h('CursorLine').bg, italic = true })
vim.api.nvim_set_hl(0, 'SymbolUsageImpl', { fg = h('@keyword').fg, bg = h('CursorLine').bg, italic = true })

local function text_format(symbol)
    local res = {}

    local round_start = { '', 'SymbolUsageRounding' }
    local round_end = { '', 'SymbolUsageRounding' }

    -- Indicator that shows if there are any other symbols in the same line
    local stacked_functions_content = symbol.stacked_count > 0 and ('+%s'):format(symbol.stacked_count) or ''

    if symbol.references then
        local usage = symbol.references <= 1 and 'usage' or 'usages'
        local num = symbol.references == 0 and 'no' or symbol.references
        table.insert(res, round_start)
        table.insert(res, { '󰌹 ', 'SymbolUsageRef' })
        table.insert(res, { ('%s %s'):format(num, usage), 'SymbolUsageContent' })
        table.insert(res, round_end)
    end

    if symbol.definition then
        if #res > 0 then
            table.insert(res, { ' ', 'NonText' })
        end
        table.insert(res, round_start)
        table.insert(res, { '󰳽 ', 'SymbolUsageDef' })
        table.insert(res, { symbol.definition .. ' defs', 'SymbolUsageContent' })
        table.insert(res, round_end)
    end

    if symbol.implementation then
        if #res > 0 then
            table.insert(res, { ' ', 'NonText' })
        end
        table.insert(res, round_start)
        table.insert(res, { '󰡱 ', 'SymbolUsageImpl' })
        table.insert(res, { symbol.implementation .. ' impls', 'SymbolUsageContent' })
        table.insert(res, round_end)
    end

    if stacked_functions_content ~= '' then
        if #res > 0 then
            table.insert(res, { ' ', 'NonText' })
        end
        table.insert(res, round_start)
        table.insert(res, { ' ', 'SymbolUsageImpl' })
        table.insert(res, { stacked_functions_content, 'SymbolUsageContent' })
        table.insert(res, round_end)
    end

    return res
end

return {
    {
        'Wansmer/symbol-usage.nvim',
        event = 'LspAttach', -- need run before LspAttach if you use nvim 0.9. On 0.10 use 'LspAttach'
        config = function()
            require('symbol-usage').setup {
                text_format = text_format,
                kinds = { SymbolKind.Function, SymbolKind.Method, SymbolKind.Class, SymbolKind.Struct, SymbolKind.Variable, SymbolKind.Constant },
            }
        end,
    },
}