lsp-config.lua

-- ----------------------------------------------------------------------
-- INFO: lsp server manager config
--
local mason_module = {
    'mason-org/mason-lspconfig.nvim',
    dependencies = {
        { 'mason-org/mason.nvim', opts = { ui = { border = 'solid' } } },
        { 'nvim-lspconfig' }
    },
    event = 'BufEnter',
}

mason_module.config = function()
    local load_local_settings = function(path, server_name)
        vim.validate('path', path, 'string')

        local fname = string.format('%s/%s.json', path, server_name)
        local ok, result = pcall(vim.fn.readfile, fname)
        if not ok or type(result) ~= 'table' or #result == 0 then return nil end

        local content = table.concat(result)
        if content == '' then return nil end

        local json_ok, decoded = pcall(vim.json.decode, content)
        if not json_ok then
            vim.notify('Failed to parse JSON from ' .. fname .. ': ' .. decoded, vim.log.levels.ERROR)
            return nil
        end

        return decoded
    end

    -- INFO: config lsp log with formatting
    vim.lsp.log.set_level 'off' --    Levels by name: "TRACE", "DEBUG", "INFO", "WARN", "ERROR", "OFF"
    -- require('vim.lsp.log').set_format_func(vim.inspect)

    -- INFO: global default capabilities for all servers
    vim.lsp.config('*', { capabilities = vim.lsp.protocol.make_client_capabilities() })

    -- INFO: load LSP configurations from individual files in ~/.config/nvim/lsp directory
    local server_names = vim.iter(vim.api.nvim_get_runtime_file('after/lsp/*.lua', true))
        :map(function(file) return vim.fn.fnamemodify(file, ':t:r') end)
        :totable()

    for _, lsp_name in ipairs(server_names) do
        -- NOTE: check local config if available and injected before lsp enabled
        local user_local_config = load_local_settings(vim.uv.cwd(), lsp_name)
        if user_local_config then
            vim.lsp.config(lsp_name, user_local_config)
        end
    end

    -- NOTE: automatically setup lsp from default config installed via mason.nvim
    require('mason-lspconfig').setup {
        ensure_installed = server_names,
        automatic_enable = true,
    }
end

-- ----------------------------------------------------------------------
-- INFO: LSP config
--
local lspconfig_module = {
    'neovim/nvim-lspconfig'
}

lspconfig_module.config = function()
    -- INFO: config lsp keymaps
    local function lsp_keymap(bufnr, mapping)
        local opts = { buffer = bufnr, silent = true, noremap = true }

        for _, keymap in pairs(mapping) do
            vim.keymap.set('n', keymap.key, keymap.cmd, opts)
        end
    end

    -- INFO: config lsp inlay hints
    local function lsp_inlayhint(client, bufnr)
        -- INFO: enable inlay hints when enter insert mode and disable when leave
        if not (client and client:supports_method('textDocument/inlayHint')) then
            return
        end

        local inlayhint_augroup = vim.api.nvim_create_augroup('inlayhint_augroup', { clear = false })
        vim.api.nvim_create_autocmd('InsertEnter', {
            buffer = bufnr,
            group = inlayhint_augroup,
            callback = function() vim.lsp.inlay_hint.enable(true, { bufnr = bufnr }) end,
        })
        vim.api.nvim_create_autocmd('InsertLeave', {
            buffer = bufnr,
            group = inlayhint_augroup,
            callback = function() vim.lsp.inlay_hint.enable(false, { bufnr = bufnr }) end,
        })
    end

    -- INFO: lsp highlight symbols
    local function lsp_highlight_symbol(client, bufnr)
        if not (client and client:supports_method('textDocument/documentHighlight')) then
            return
        end

        bufnr = bufnr and bufnr ~= 0 and bufnr or vim.api.nvim_get_current_buf()

        local augroup = vim.api.nvim_create_augroup('lsp_highlight_symbol', { clear = false })
        local autocmd_opts = { group = augroup, buffer = bufnr }

        vim.api.nvim_clear_autocmds(autocmd_opts)

        vim.api.nvim_create_autocmd({ 'CursorHold', 'InsertLeave' },
            vim.tbl_extend('force', autocmd_opts, {
                callback = vim.lsp.buf.document_highlight,
            })
        )

        vim.api.nvim_create_autocmd({ 'CursorMoved', 'InsertEnter', 'BufLeave' },
            vim.tbl_extend('force', autocmd_opts, {
                callback = vim.lsp.buf.clear_references,
            })
        )
    end

    -- NOTE: lsp attach callback
    vim.api.nvim_create_autocmd('LspAttach', {
        desc = 'LSP features',
        group = vim.api.nvim_create_augroup('LspFeatures', {}),
        callback = function(event)
            local bufnr = event.buf
            local client = assert(vim.lsp.get_client_by_id(event.data.client_id))

            lsp_keymap(bufnr, require('config.keymaps').lsp)
            lsp_inlayhint(client, bufnr)
            lsp_highlight_symbol(client, bufnr)
        end
    })
end


-- ----------------------------------------------------------------------
-- INFO: Diagnostics config
--
local diagnostic_module = {
    'dgagn/diagflow.nvim',
    event = 'LspAttach',
}

diagnostic_module.init = function()
    vim.diagnostic.config {
        update_in_insert = false,
        severity_sort = true,
        virtual_text = false,
        virtual_lines = false,
        signs = {
            text = {
                [vim.diagnostic.severity.ERROR] = '',
                [vim.diagnostic.severity.WARN] = '',
                [vim.diagnostic.severity.INFO] = '',
                [vim.diagnostic.severity.HINT] = '',
            },
            numhl = {
                [vim.diagnostic.severity.ERROR] = 'DiagnosticError',
                [vim.diagnostic.severity.WARN] = 'DiagnosticWarn',
                [vim.diagnostic.severity.INFO] = 'DiagnosticInfo',
                [vim.diagnostic.severity.HINT] = 'DiagnosticHint',
            },
        }
    }
end

diagnostic_module.opts = {
    scope = 'line',
    padding_top = 2,
    toggle_event = { 'InsertEnter', 'InsertLeave' },
    severity_colors = {
        error = 'DiagnosticError',
        warn = 'DiagnosticWarn',
        info = 'DiagnosticInfo',
        hint = 'DiagnosticHint',
    },
}

return {
    mason_module,
    lspconfig_module,
    diagnostic_module,
}