-- mod-version:3 -- lite-xl 2.1.8
local core     = require "core"
local style    = require "core.style"
local command  = require "core.command"
local View     = require "core.view"
local process  = require "process"     -- Child Processes API
local config   = require "core.config"

local active_views = {}

-- ---------- JPDebugView: a simple scrollable log view ----------
---@class JPDebugView : core.view
local JPDebugView = View:extend()

function JPDebugView:new(title)
  JPDebugView.super.new(self)
  self.scrollable = true
  self.caption = title or "JP Debug"
  self.lines = { "[jpdebug] ready.\n" }
  self.max_lines = 5000 -- keep memory bounded
  self.font = style.code_font
  self.line_h = self.font:get_height()
end

function JPDebugView:get_name()
  return self.caption
end

function JPDebugView:get_scrollable_size()
  return math.max(#self.lines * self.line_h + style.padding.y * 2, self.size.y)
end

function JPDebugView:push(kind, s)
  if not s or s == "" then return end
  -- split on newlines; prefix stderr
  for line in (s .. "\n"):gmatch("(.-)\n") do
    if kind == "stderr" then
      line = "[stderr] " .. line
    else
      line = "[stdout] " .. line
    end
    self.lines[#self.lines + 1] = line
    if #self.lines > self.max_lines then
      local drop = #self.lines - self.max_lines
      for _ = 1, drop do table.remove(self.lines, 1) end
    end
  end
  -- autoscroll to bottom
  self.scroll.to.y = self:get_scrollable_size()
  core.redraw = true
end

function JPDebugView:clear()
  self.lines = {}
  core.redraw = true
end

function JPDebugView:draw()
  self:draw_background(style.background)
  local ox, oy = self:get_content_offset()
  local x = ox + style.padding.x
  local y = oy + style.padding.y
  renderer.draw_rect(self.position.x, self.position.y, self.size.x, self.size.y, style.background)
  for i = 1, #self.lines do
    renderer.draw_text(self.font, self.lines[i], x, y, style.text)
    y = y + self.line_h
  end
  self:draw_scrollbar()
end

-- ---------- helper: pick a target from project module ----------
local function get_targets()
  local t = (config.plugins and config.plugins.jpdebug and config.plugins.jpdebug.targets) or {}
  return t
end

local function get_selected_target()
  local t = (config.plugins and config.plugins.jpdebug and config.plugins.jpdebug.target) or {}
  return t
end

-- ---------- run target & pipe stdout/stderr into the view ----------
local function run_target(target, name)
  local title = ("JP Debug: %s"):format(name)

  local view = nil
  if active_views[title] then
    -- If there is already a view use that one
    view = active_views[title]
  else
    -- Otherwhise lets make one
    view = JPDebugView(title)
    core.root_view:get_active_node():add_view(view)
    active_views[title] = view
  end

  local opts = {
    cwd   = target.cwd,
    stdout = process.REDIRECT_PIPE,
    stderr = process.REDIRECT_PIPE
  }
  view:clear()
  local proc = process.start({"lua", target.file}, opts)

  -- background pump (non-blocking I/O)
  core.add_thread(function()
    while true do
      coroutine.yield(0.016) -- ~60fps
      local out = proc:read_stdout()
      if out == nil then
        -- stdout pipe closed: try drain stderr and break when both closed
        local err = proc:read_stderr()
        if err ~= nil and err ~= "" then view:push("stderr", err) end
        break
      end
      if out ~= "" then view:push("stdout", out) end
      local err = proc:read_stderr()
      if err ~= nil and err ~= "" then view:push("stderr", err) end
    end
    local code = proc:wait(process.WAIT_INFINITE)
    view:push("stdout", ("\n[exit] code=%s\n"):format(tostring(code)))
  end)

  return view
end

command.add(false, {
  ["jpdebug:run"] = function()
    local targets = get_targets()
    local target = get_selected_target()
    if target then
      if targets[target] then
        core.log('[jpdebug] Starting target %s', target)
        run_target(targets[target], target)
      else
        core.error("[jpdebug] Selected target not existing in targets list")
        return
      end
    else
      core.error("[jpdebug] No target selected in project module")
      return
    end
  end,
})