local core = require "core"
local process  = require "process"

---@class shell: runner
local shell = {
  name = "shell",
  proc = nil ---@type process|nil
}

function shell:new(o)
  o = o or {}
  setmetatable(o, self)
  self.__index = self
  return o
end

---@meta
function shell.log(msg) end
---@meta
function shell.error(msg) end
---@meta
function shell.stdout(msg) end
---@meta
function shell.stderr(msg) end
---@meta
function shell.exited() end


function shell:run(target, name)
  local opts = {
        cwd = target.cwd or ".",
        env = target.env or {},
        stdout = process.REDIRECT_PIPE,
        stderr = process.REDIRECT_PIPE
      }
  if target.cmd then
    self.proc = process.start(target.cmd, opts)
    if not self.proc then
      self.error("Could not start process...")
      return
    end
  else
    self.error(string.format("command not specified for target %s", name))
  end

  -- output pump
  core.add_thread(function()
    while true do
      core.redraw = true
      coroutine.yield(0.016) -- 60FPS
      local sout = self.proc:read_stdout()
      local serr = self.proc:read_stderr()
      if sout == nil and serr == nil then
        self.exited()
        break
      end
      if sout and sout~="" then self.stdout(sout) end
      if serr and serr~="" then self.stderr(serr) end
    end
  end)
end

function shell:wait(time)
  if not self.proc then return end
  return self.proc:wait(time)
end

function shell:kill()
  if not self.proc then return end
  self.proc:kill()
end

function shell:terminate()
  if not self.proc then return end
  self.proc:terminate()
end

return shell