-- OpenQASM for an editor configured in Lua: the file type, the language
-- server (`wai-quantum lsp`), the tree-sitter grammar, and the debugger
-- (`wai-quantum dap`) for the debug adapter plugin.
--
-- Copy this file into your configuration's plugin/ directory, where it runs
-- at start. With the tree-sitter plugin, `:TSInstall openqasm` builds the
-- grammar; if your version of the plugin does not install its queries, copy
-- wai/tools/tree-sitter-openqasm/queries/*.scm to queries/openqasm/ in your
-- configuration directory.

vim.filetype.add({ extension = { qasm = 'openqasm' } })

local server = {
  cmd = { 'wai-quantum', 'lsp' },
  filetypes = { 'openqasm' },
  root_markers = { '.git' },
  -- The values a generator's inputs are read at, and the shots a run samples.
  settings = { ['wai-quantum'] = { inputs = {} } },
}

if vim.lsp.config and vim.lsp.enable then
  -- Version 0.11 and later: the built-in configuration.
  vim.lsp.config('wai_quantum', server)
  vim.lsp.enable('wai_quantum')
else
  -- Earlier versions: through the lspconfig plugin.
  local ok, configs = pcall(require, 'lspconfig.configs')
  if ok then
    if not configs.wai_quantum then
      configs.wai_quantum = {
        default_config = {
          cmd = server.cmd,
          filetypes = server.filetypes,
          root_dir = require('lspconfig.util').root_pattern('.git'),
          single_file_support = true,
          settings = server.settings,
        },
      }
    end
    require('lspconfig').wai_quantum.setup({})
  end
end

-- The grammar, which the tree-sitter plugin builds from the repository.
local grammar = {
  url = 'https://git.transaction.science/Transaction-Science/open-standards',
  location = 'wai/tools/tree-sitter-openqasm',
  branch = 'main',
}
local ok, parsers = pcall(require, 'nvim-treesitter.parsers')
if ok and parsers.get_parser_configs then
  -- The plugin's earlier interface.
  parsers.get_parser_configs().openqasm = {
    install_info = { url = grammar.url, location = grammar.location, branch = grammar.branch, files = { 'src/parser.c' } },
    filetype = 'openqasm',
  }
elseif ok then
  -- Its current interface: registered each time it reads its list of parsers.
  vim.api.nvim_create_autocmd('User', {
    pattern = 'TSUpdate',
    callback = function()
      require('nvim-treesitter.parsers').openqasm = {
        install_info = { url = grammar.url, location = grammar.location, branch = grammar.branch, queries = 'queries' },
      }
    end,
  })
end
vim.treesitter.language.register('openqasm', 'openqasm')

-- Highlight OpenQASM with the grammar, once it is built.
vim.api.nvim_create_autocmd('FileType', {
  pattern = 'openqasm',
  callback = function(args)
    pcall(vim.treesitter.start, args.buf, 'openqasm')
  end,
})

-- The engine's commands, as the lenses run them: :QuantumRun, :QuantumPlan,
-- :QuantumCritique, :QuantumShortcuts, :QuantumReceipt.
for _, name in ipairs({ 'run', 'plan', 'critique', 'shortcuts', 'receipt' }) do
  local title = name:sub(1, 1):upper() .. name:sub(2)
  vim.api.nvim_create_user_command('Quantum' .. title, function()
    local buf = vim.api.nvim_get_current_buf()
    local client = vim.lsp.get_clients({ bufnr = buf, name = 'wai_quantum' })[1]
    if not client then
      vim.notify('the wai-quantum language server is not running in this buffer', vim.log.levels.WARN)
      return
    end
    local params = { command = 'wai-quantum.' .. name, arguments = { vim.uri_from_bufnr(buf) } }
    client:request('workspace/executeCommand', params, function(err, answer)
      if err then
        vim.notify(err.message, vim.log.levels.ERROR)
        return
      end
      vim.schedule(function()
        vim.cmd('botright new')
        vim.bo.buftype = 'nofile'
        vim.bo.bufhidden = 'wipe'
        vim.api.nvim_buf_set_lines(0, 0, -1, false, vim.split(answer.text, '\n'))
        vim.api.nvim_buf_set_name(0, 'wai-quantum ' .. name)
      end)
    end, buf)
  end, {})
end

-- The engine's debugger, with the debug adapter plugin: breakpoints by line,
-- steps forward and back, and the state's probes as variables.
local has_dap, dap = pcall(require, 'dap')
if has_dap then
  dap.adapters['wai-quantum'] = { type = 'executable', command = 'wai-quantum', args = { 'dap' } }
  dap.configurations.openqasm = {
    { type = 'wai-quantum', request = 'launch', name = 'Debug the program', program = '${file}', stopOnEntry = true },
  }
end