init.lua

-- Replaces the archived nvim-treesitter plugin with a thin local installer.
-- Loaded as a module (NOT a lazy spec) from init.lua via `require "user.treesitter"`.
local install = require("user.treesitter.install")

-- Built-in nvim ftplugins (e.g. runtime/ftplugin/lua.lua) call
-- vim.treesitter.start() unconditionally and throw if the parser isn't
-- installed yet. Since our installer is async, that race produces a noisy
-- BufReadPost error on first open. Wrap start() so a missing parser is a
-- silent no-op; install_one() retroactively starts ts on open buffers
-- once the parser becomes available.
do
    local orig_start = vim.treesitter.start
    vim.treesitter.start = function(buf, lang)
        local ok, err = pcall(orig_start, buf, lang)
        if not ok and not tostring(err):match("Parser could not be created") then
            error(err)
        end
    end
end

local ensure_installed = {
    "lua",
    "vim",
    "vimdoc",
    "regex",
    "markdown",
    "markdown_inline",
    "html",
    "typst",
    "yaml",
    "latex",
    "bash",
    "python",
    "foam",
    "cpp",
    "c",
    "rust",
    "glsl",
    "xonsh",
    "json",
}

local function complete_langs()
    return install.parser_names()
end

vim.api.nvim_create_user_command("TSInstall", function(args)
    install.install(args.fargs, true)
end, { nargs = "+", complete = complete_langs })

vim.api.nvim_create_user_command("TSUpdate", function(args)
    local langs = #args.fargs > 0 and args.fargs or ensure_installed
    install.install(langs, true)
end, { nargs = "*", complete = complete_langs })

vim.api.nvim_create_user_command("TSUninstall", function(args)
    install.uninstall(args.fargs)
end, { nargs = "+", complete = complete_langs })

vim.api.nvim_create_user_command("TSHealth", function()
    local ok = install.recheck_prereqs()
    local lines = { "treesitter prereqs: " .. (ok and "OK" or "FAIL") }
    table.insert(lines, "install dir: " .. vim.fs.joinpath(vim.fn.stdpath("data"), "site", "parser"))
    table.insert(lines, "ABI: " .. tostring(vim.treesitter.language_version))
    local installed = vim.fn.glob(vim.fs.joinpath(vim.fn.stdpath("data"), "site", "parser", "*.so"), false, true)
    table.insert(lines, ("installed parsers: %d"):format(#installed))
    for _, p in ipairs(installed) do
        table.insert(lines, "  " .. vim.fs.basename(p))
    end
    vim.notify(table.concat(lines, "\n"), vim.log.levels.INFO)
end, {})

-- On every FileType: if our registry knows this lang, either start TS
-- (parser installed) or kick off a background install (the installer's
-- retro-start hook will attach TS to this buffer once the build finishes).
local known = {}
for _, lang in ipairs(install.parser_names()) do
    known[lang] = true
end

vim.api.nvim_create_autocmd("FileType", {
    callback = function(args)
        local ft = args.match
        if not known[ft] then
            return
        end
        if install.is_installed(ft) then
            vim.defer_fn(function()
                if vim.api.nvim_buf_is_valid(args.buf) then
                    pcall(vim.treesitter.start, args.buf)
                end
            end, 1)
        else
            install.install({ ft }, false)
        end
    end,
})

vim.opt.foldexpr = "v:lua.vim.treesitter.foldexpr()"

-- Add the curated nvim-treesitter query bundle to rtp so "; inherits: X"
-- directives in highlights.scm (e.g. javascript inherits ecma,jsx) resolve.
-- Must run AFTER lazy.nvim rebuilds rtp, so use VimEnter.
vim.api.nvim_create_autocmd("VimEnter", {
    once = true,
    callback = function()
        local nvimts_rt = install.nvimts_queries_runtime()
        if nvimts_rt and vim.fn.isdirectory(nvimts_rt) == 1 then
            vim.opt.runtimepath:prepend(nvimts_rt)
        end
    end,
})

-- Install missing parsers asynchronously after startup.
vim.schedule(function()
    install.install(ensure_installed, false)
end)