local util = require("test-samurai.util")

local M = {}

local default_filetypes = {
  javascript = true,
  javascriptreact = true,
  typescript = true,
  typescriptreact = true,
}

local default_patterns = { ".test.", ".spec." }

local function is_js_test_file(bufnr, filetypes, patterns)
  local ft = vim.bo[bufnr].filetype
  if not filetypes[ft] then
    return false
  end
  local path = util.get_buf_path(bufnr)
  if not path or path == "" then
    return false
  end
  for _, pat in ipairs(patterns) do
    if path:find(pat, 1, true) then
      return true
    end
  end
  return false
end

local function find_nearest_test(bufnr, row)
  local lines = util.get_buf_lines(bufnr)
  local start = row + 1
  if start > #lines then
    start = #lines
  elseif start < 1 then
    start = 1
  end
  for i = start, 1, -1 do
    local line = lines[i]
    local call, name = line:match("^%s*(it|test|describe)%s*%(%s*['"`]([^'"`]+)['"`]")
    if call and name then
      return {
        kind = call,
        name = name,
        line = i - 1,
      }
    end
  end
  return nil
end

function M.new(opts)
  local cfg = opts or {}
  local runner = {}

  runner.name = cfg.name or "js"
  runner.framework = cfg.framework or "jest"
  runner.command = cfg.command or { "npx", runner.framework }

  runner.filetypes = {}
  if cfg.filetypes then
    for _, ft in ipairs(cfg.filetypes) do
      runner.filetypes[ft] = true
    end
  else
    runner.filetypes = vim.deepcopy(default_filetypes)
  end

  runner.patterns = cfg.patterns or default_patterns

  function runner.is_test_file(bufnr)
    return is_js_test_file(bufnr, runner.filetypes, runner.patterns)
  end

  function runner.find_nearest(bufnr, row, _col)
    if not runner.is_test_file(bufnr) then
      return nil, "not a JS/TS test file"
    end
    local hit = find_nearest_test(bufnr, row)
    if not hit then
      return nil, "no test call found"
    end
    local path = util.get_buf_path(bufnr)
    local root = util.find_root(path, {
      "jest.config.js",
      "jest.config.ts",
      "vitest.config.ts",
      "vitest.config.js",
      "package.json",
      "node_modules",
    })
    return {
      file = path,
      cwd = root,
      framework = runner.framework,
      test_name = hit.name,
      kind = hit.kind,
    }
  end

  local function build_jest(spec)
    local cmd = vim.deepcopy(runner.command)
    table.insert(cmd, spec.file)
    table.insert(cmd, "-t")
    table.insert(cmd, spec.test_name)
    return cmd
  end

  local function build_mocha(spec)
    local cmd = vim.deepcopy(runner.command)
    table.insert(cmd, spec.file)
    table.insert(cmd, "--grep")
    table.insert(cmd, spec.test_name)
    return cmd
  end

  local function build_vitest(spec)
    local cmd = vim.deepcopy(runner.command)
    table.insert(cmd, spec.file)
    table.insert(cmd, "-t")
    table.insert(cmd, spec.test_name)
    return cmd
  end

  function runner.build_command(spec)
    local fw = runner.framework
    local cmd
    if fw == "jest" then
      cmd = build_jest(spec)
    elseif fw == "mocha" then
      cmd = build_mocha(spec)
    elseif fw == "vitest" then
      cmd = build_vitest(spec)
    else
      cmd = vim.deepcopy(runner.command)
      table.insert(cmd, spec.file)
    end
    return {
      cmd = cmd,
      cwd = spec.cwd,
    }
  end

  return runner
end

return M