-- golines A golang formatter that fixes long lines
-- golines + goimport
local api = vim.api
local utils = require('go.utils')
local log = utils.log
local max_len = _GO_NVIM_CFG.max_line_len or 120
local gofmt = _GO_NVIM_CFG.gofmt or 'gofumpt'
local vfn = vim.fn
local install = require('go.install').install
local gofmt_args = _GO_NVIM_CFG.gofmt_args or {
  '--max-len=' .. tostring(max_len),
  '--base-formatter=' .. gofmt,
}

local goimport_args = _GO_NVIM_CFG.goimport_args
  or {
    '--max-len=' .. tostring(max_len),
    '--base-formatter=goimports',
  }

if vim.lsp.buf.format == nil then
  -- vim.notify('the vim.lsp.buf.format is not available, some feature is missing if you are running old version of neovim (<0.8.0)', vim.lsp.log_levels.DEBUG)
  -- neovim < 0.7 only
  require('go.lsp') -- this set default value of format
end

local run = function(fmtargs, bufnr, cmd)
  bufnr = bufnr or 0
  log(fmtargs, bufnr, cmd)
  if cmd == 'gopls' then
    if not vim.api.nvim_buf_is_loaded(bufnr) then
      vfn.bufload(bufnr)
    end

    if vim.o.mod == true then
      vim.cmd('write')
    end
    -- log gopls format
    return vim.lsp.buf.format({
      async = _GO_NVIM_CFG.lsp_fmt_async,
      bufnr = bufnr,
      name = 'gopls',
    })
  end

  local args = vim.deepcopy(fmtargs)
  table.insert(args, api.nvim_buf_get_name(bufnr))
  log('formatting buffer... ' .. vim.inspect(args), vim.lsp.log_levels.DEBUG)

  if bufnr == 0 then
    if vfn.getbufinfo('%')[1].changed == 1 then
      vim.cmd('write')
    end
  end

  local old_lines = api.nvim_buf_get_lines(0, 0, -1, true)
  if cmd then
    table.insert(args, 1, cmd)
  else
    table.insert(args, 1, 'golines')
  end
  log('fmt cmd:', args)

  local j = vfn.jobstart(args, {
    on_stdout = function(_, data, _)
      data = utils.handle_job_data(data)
      if not data then
        return
      end
      if not utils.check_same(old_lines, data) then
        vim.notify('updating codes', vim.lsp.log_levels.DEBUG)
        api.nvim_buf_set_lines(0, 0, -1, false, data)
        vim.cmd('write')
      else
        vim.notify('already formatted', vim.lsp.log_levels.DEBUG)
      end
      -- log("stdout" .. vim.inspect(data))
      old_lines = nil
    end,
    on_stderr = function(_, data, _)
      data = utils.handle_job_data(data)
      if data then
        log(vim.inspect(data) .. ' from stderr')
      end
    end,
    on_exit = function(_, data, _) -- id, data, event
      -- log(vim.inspect(data) .. "exit")
      if data ~= 0 then
        return vim.notify('golines failed ' .. tostring(data), vim.lsp.log_levels.ERROR)
      end
      old_lines = nil
      vim.defer_fn(function()
        if vfn.getbufinfo('%')[1].changed == 1 then
          vim.cmd('write')
        end
      end, 300)
    end,
    stdout_buffered = true,
    stderr_buffered = true,
  })
  vfn.chansend(j, old_lines)
  vfn.chanclose(j, 'stdin')
end

local M = {}
M.gofmt = function(...)
  local long_opts = {
    all = 'a',
  }

  local short_opts = 'a'
  local args = ... or {}

  local getopt = require('go.alt_getopt')
  local optarg = getopt.get_opts(args, short_opts, long_opts)
  log(optarg)

  local all_buf = false
  if optarg['a'] then
    all_buf = true
  end
  if not install(gofmt) then
    utils.warn('installing ' .. gofmt .. ' please retry after installation')
    return
  end
  if not install('golines') then
    utils.warn('installing golines , please rerun format after install finished')
    return
  end
  local a = {}
  utils.copy_array(gofmt_args, a)
  local fmtcmd
  if gofmt == 'gopls' then
    fmtcmd = 'gopls'
  end
  if all_buf then
    log('fmt all buffers')
    vim.cmd('wall')
    local bufs = utils.get_active_buf()
    log(bufs)

    for _, b in ipairs(bufs) do
      log(a, b)
      run(a, b.bufnr, fmtcmd)
    end
  else
    if vfn.getbufinfo('%')[1].changed == 1 then
      vim.cmd('write')
    end
    run(a, 0, fmtcmd)
  end
end

M.org_imports = function(wait_ms)
  local codeaction = require('go.lsp').codeaction
  codeaction('', 'source.organizeImports', wait_ms)
  if _GO_NVIM_CFG.lsp_fmt_async then
    vim.defer_fn(function()
      vim.lsp.buf.format({ async = true })
    end, 100)
  else
    vim.lsp.buf.format({ async = false })
  end
end

M.goimport = function(...)
  local goimport = _GO_NVIM_CFG.goimport or 'goimports'
  local args = { ... }
  log(args, goimport)
  if _GO_NVIM_CFG.goimport == 'gopls' then
    if vfn.empty(args) == 1 then
      return M.org_imports(1000)
    else
      local path = select(1, ...)
      local gopls = require('go.gopls')
      return gopls.import(path)
    end
  end
  local buf = vim.api.nvim_get_current_buf()
  require('go.install').install(goimport)
  -- specified the pkg name
  if #args > 0 then -- dont use golines
    return run(args, buf, 'goimports')
  end

  -- golines base formatter is goimports
  local a = {}
  if goimport == 'golines' then
    a = vim.deepcopy(goimport_args)
  end
  run(a, buf, goimport)
end

return M