--- @brief
---
--- https://github.com/hrsh7th/vscode-langservers-extracted
---
--- `vscode-eslint-language-server` is a linting engine for JavaScript / Typescript.
--- It can be installed via `npm`:
---
--- ```sh
--- npm i -g vscode-langservers-extracted
--- ```
---
--- The default `on_attach` config provides the `LspEslintFixAll` command that can be used to format a document on save:
--- ```lua
--- local base_on_attach = vim.lsp.config.eslint.on_attach
--- vim.lsp.config("eslint", {
---   on_attach = function(client, bufnr)
---     if not base_on_attach then return end
---
---     base_on_attach(client, bufnr)
---     vim.api.nvim_create_autocmd("BufWritePre", {
---       buffer = bufnr,
---       command = "LspEslintFixAll",
---     })
---   end,
--- })
--- ```
---
--- See [vscode-eslint](https://github.com/microsoft/vscode-eslint/blob/55871979d7af184bf09af491b6ea35ebd56822cf/server/src/eslintServer.ts#L216-L229) for configuration options.
---
--- Messages handled in lspconfig: `eslint/openDoc`, `eslint/confirmESLintExecution`, `eslint/probeFailed`, `eslint/noLibrary`
---
--- Additional messages you can handle: `eslint/noConfig`
---
--- ### Monorepo support
---
--- `vscode-eslint-language-server` supports monorepos by default. It will automatically find the config file corresponding to the package you are working on. You can use different configs in different packages.
--- This works without the need of spawning multiple instances of `vscode-eslint-language-server`.
--- You can use a different version of ESLint in each package, but it is recommended to use the same version of ESLint in all packages. The location of the ESLint binary will be determined automatically.
---
--- /!\ When using flat config files, you need to use them across all your packages in your monorepo, as it's a global setting for the server.

local util = require 'lspconfig.util'
local lsp = vim.lsp

local eslint_config_files = {
  '.eslintrc',
  '.eslintrc.js',
  '.eslintrc.cjs',
  '.eslintrc.yaml',
  '.eslintrc.yml',
  '.eslintrc.json',
  'eslint.config.js',
  'eslint.config.mjs',
  'eslint.config.cjs',
  'eslint.config.ts',
  'eslint.config.mts',
  'eslint.config.cts',
}

---@type vim.lsp.Config
return {
  cmd = { 'vscode-eslint-language-server', '--stdio' },
  filetypes = {
    'javascript',
    'javascriptreact',
    'javascript.jsx',
    'typescript',
    'typescriptreact',
    'typescript.tsx',
    'vue',
    'svelte',
    'astro',
    'htmlangular',
  },
  workspace_required = true,
  on_attach = function(client, bufnr)
    vim.api.nvim_buf_create_user_command(0, 'LspEslintFixAll', function()
      client:request_sync('workspace/executeCommand', {
        command = 'eslint.applyAllFixes',
        arguments = {
          {
            uri = vim.uri_from_bufnr(bufnr),
            version = lsp.util.buf_versions[bufnr],
          },
        },
      }, nil, bufnr)
    end, {})
  end,
  root_dir = function(bufnr, on_dir)
    -- The project root is where the LSP can be started from
    -- As stated in the documentation above, this LSP supports monorepos and simple projects.
    -- We select then from the project root, which is identified by the presence of a package
    -- manager lock file.
    local root_markers = { 'package-lock.json', 'yarn.lock', 'pnpm-lock.yaml', 'bun.lockb', 'bun.lock' }
    -- Give the root markers equal priority by wrapping them in a table
    root_markers = vim.fn.has('nvim-0.11.3') == 1 and { root_markers } or root_markers
    local project_root = vim.fs.root(bufnr, root_markers)
    if not project_root then
      return
    end

    -- We know that the buffer is using ESLint if it has a config file
    -- in its directory tree.
    --
    -- Eslint used to support package.json files as config files, but it doesn't anymore.
    -- We keep this for backward compatibility.
    local filename = vim.api.nvim_buf_get_name(bufnr)
    local eslint_config_files_with_package_json =
      util.insert_package_json(eslint_config_files, 'eslintConfig', filename)
    local is_buffer_using_eslint = vim.fs.find(eslint_config_files_with_package_json, {
      path = filename,
      type = 'file',
      limit = 1,
      upward = true,
      stop = vim.fs.dirname(project_root),
    })[1]
    if not is_buffer_using_eslint then
      return
    end

    on_dir(project_root)
  end,
  -- Refer to https://github.com/Microsoft/vscode-eslint#settings-options for documentation.
  settings = {
    validate = 'on',
    packageManager = nil,
    useESLintClass = false,
    experimental = {
      useFlatConfig = false,
    },
    codeActionOnSave = {
      enable = false,
      mode = 'all',
    },
    format = true,
    quiet = false,
    onIgnoredFiles = 'off',
    rulesCustomizations = {},
    run = 'onType',
    problems = {
      shortenToSingleLine = false,
    },
    -- nodePath configures the directory in which the eslint server should start its node_modules resolution.
    -- This path is relative to the workspace folder (root dir) of the server instance.
    nodePath = '',
    -- use the workspace folder location or the file location (if no workspace folder is open) as the working directory
    workingDirectory = { mode = 'auto' },
    codeAction = {
      disableRuleComment = {
        enable = true,
        location = 'separateLine',
      },
      showDocumentation = {
        enable = true,
      },
    },
  },
  before_init = function(_, config)
    -- The "workspaceFolder" is a VSCode concept. It limits how far the
    -- server will traverse the file system when locating the ESLint config
    -- file (e.g., .eslintrc).
    local root_dir = config.root_dir

    if root_dir then
      config.settings = config.settings or {}
      config.settings.workspaceFolder = {
        uri = root_dir,
        name = vim.fn.fnamemodify(root_dir, ':t'),
      }

      -- Support flat config files
      -- They contain 'config' in the file name
      local flat_config_files = vim.tbl_filter(function(file)
        return file:match('config')
      end, eslint_config_files)

      for _, file in ipairs(flat_config_files) do
        local found_files = vim.fn.globpath(root_dir, file, true, true)

        -- Filter out files inside node_modules
        local filtered_files = {}
        for _, found_file in ipairs(found_files) do
          if string.find(found_file, '[/\\]node_modules[/\\]') == nil then
            table.insert(filtered_files, found_file)
          end
        end

        if #filtered_files > 0 then
          config.settings.experimental = config.settings.experimental or {}
          config.settings.experimental.useFlatConfig = true
          break
        end
      end

      -- Support Yarn2 (PnP) projects
      local pnp_cjs = root_dir .. '/.pnp.cjs'
      local pnp_js = root_dir .. '/.pnp.js'
      if vim.uv.fs_stat(pnp_cjs) or vim.uv.fs_stat(pnp_js) then
        local cmd = config.cmd
        config.cmd = vim.list_extend({ 'yarn', 'exec' }, cmd)
      end
    end
  end,
  handlers = {
    ['eslint/openDoc'] = function(_, result)
      if result then
        vim.ui.open(result.url)
      end
      return {}
    end,
    ['eslint/confirmESLintExecution'] = function(_, result)
      if not result then
        return
      end
      return 4 -- approved
    end,
    ['eslint/probeFailed'] = function()
      vim.notify('[lspconfig] ESLint probe failed.', vim.log.levels.WARN)
      return {}
    end,
    ['eslint/noLibrary'] = function()
      vim.notify('[lspconfig] Unable to find ESLint library.', vim.log.levels.WARN)
      return {}
    end,
  },
}
