-- part of the code from polarmutex/contextprint.nvim

local ts_utils = require("nvim-treesitter.ts_utils")
local ts_query = require("nvim-treesitter.query")
local parsers = require("nvim-treesitter.parsers")
local locals = require("nvim-treesitter.locals")
local utils = require("go.ts.utils")
local ulog = require("go.utils").log

local M = {}

-- Array<node_wrapper>
M.intersect_nodes = function(nodes, row, col)
  local found = {}
  for idx = 1, #nodes do
    local node = nodes[idx]
    local sRow = node.dim.s.r
    local sCol = node.dim.s.c
    local eRow = node.dim.e.r
    local eCol = node.dim.e.c

    if utils.intersects(row, col, sRow, sCol, eRow, eCol) then
      table.insert(found, node)
    end
  end

  return found
end

M.count_parents = function(node)
  local count = 0
  local n = node.declaring_node
  while n ~= nil do
    n = n:parent()
    count = count + 1
  end
  return count
end

-- @param nodes Array<node_wrapper>
-- perf note.  I could memoize some values here...
M.sort_nodes = function(nodes)
  table.sort(
    nodes,
    function(a, b)
      return M.count_parents(a) < M.count_parents(b)
    end
  )
  return nodes
end

-- local lang = vim.api.nvim_buf_get_option(bufnr, 'ft')
-- node_wrapper
-- returns [{
--   declaring_node = tsnode
--   dim: {s: {r, c}, e: {r, c}},
--   name: string
--   type: string
-- }]
M.get_nodes = function(query, lang, defaults, bufnr)
  bufnr = bufnr or 0
  local success, parsed_query =
    pcall(
    function()
      return vim.treesitter.parse_query(lang, query)
    end
  )
  if not success then
    return nil
  end

  local parser = parsers.get_parser(bufnr, lang)
  local root = parser:parse()[1]:root()
  local start_row, _, end_row, _ = root:range()
  -- local n = ts_utils.get_node_at_cursor()
  -- local a, b, c, d = ts_utils.get_node_range(n)
  local results = {}
  for match in ts_query.iter_prepared_matches(parsed_query, root, bufnr, start_row, end_row) do
    local sRow, sCol, eRow, eCol
    local declaration_node
    local type = "nil"
    local name = "nil"
    locals.recurse_local_nodes(
      match,
      function(_, node, path)
        local idx = string.find(path, ".", 1, true)
        local op = string.sub(path, idx + 1, #path)

        local a1, b1, c1, d1 = ts_utils.get_node_range(node)

        type = string.sub(path, 1, idx - 1)
        if name == nil then
          name = defaults[type] or "empty"
        end

        if op == "name" then
          name = ts_utils.get_node_text(node)[1]
        elseif op == "declaration" then
          declaration_node = node
          sRow, sCol, eRow, eCol = node:range()
          sRow = sRow + 1
          eRow = eRow + 1
          sCol = sCol + 1
          eCol = eCol + 1
        end
      end
    )

    if declaration_node ~= nil then
      table.insert(
        results,
        {
          declaring_node = declaration_node,
          dim = {
            s = {r = sRow, c = sCol},
            e = {r = eRow, c = eCol}
          },
          name = name,
          type = type
        }
      )
    end
  end

  return results
end

-- local lang = vim.api.nvim_buf_get_option(bufnr, 'ft')
-- node_wrapper
-- returns {
--   declaring_node = tsnode
--   dim: {s: {r, c}, e: {r, c}},
--   name: string
--   type: string
-- }
M.get_all_nodes = function(query, lang, defaults, bufnr, pos_row, pos_col)
  bufnr = bufnr or 0
  -- todo a huge number
  pos_row = pos_row or 30000
  local success, parsed_query =
    pcall(
    function()
      return vim.treesitter.parse_query(lang, query)
    end
  )
  if not success then
    return nil
  end

  local parser = parsers.get_parser(bufnr, lang)
  local root = parser:parse()[1]:root()
  local start_row, _, end_row, _ = root:range()
  -- local n = ts_utils.get_node_at_cursor()
  -- local a, b, c, d = ts_utils.get_node_range(n)
  -- ulog("node range " .. tostring(a) .. tostring(b) .. tostring(c).. tostring(d))
  -- ulog("cru node:" .. vim.inspect(n) .. "text: " .. vim.inspect(ts_utils.get_node_text(n)))
  local results = {}
  for match in ts_query.iter_prepared_matches(parsed_query, root, bufnr, start_row, end_row) do
    local sRow, sCol, eRow, eCol
    local declaration_node
    local type = ""
    local name = ""
    local op = ""
    local method_receiver = ""

    locals.recurse_local_nodes(
      match,
      function(_, node, path)
        --local idx = string.find(path, ".", 1, true)
        local idx = string.find(path, ".[^.]*$")  -- find last .
        op = string.sub(path, idx + 1, #path)
        local a1, b1, c1, d1 = ts_utils.get_node_range(node)
        local dbg_txt = ts_utils.get_node_text(node, bufnr)[1]
        type = string.sub(path, 1, idx - 1)

        ulog( "node" ..  vim.inspect(node) ..  "\n path: " ..  path ..  " op: " ..  op .. "  type: " .. type .. "\n txt: " ..  dbg_txt ..  "\n range: " ..  tostring(a1) .. ":" .. tostring(b1) .. " TO " .. tostring(c1) .. ":" .. tostring(d1))
        --
        -- may not handle complex node
        if op == "name" then
          -- ulog("node name " .. name)
          name = ts_utils.get_node_text(node, bufnr)[1]
        elseif op == "declaration" or op == "clause" then
          declaration_node = node
          sRow, sCol, eRow, eCol = node:range()
          sRow = sRow + 1
          eRow = eRow + 1
          sCol = sCol + 1
          eCol = eCol + 1
        end
      end
    )
    if declaration_node ~= nil then
      -- ulog(name .. " " .. op)
      -- ulog(sRow, pos_row)
      if sRow > pos_row then
        ulog("beyond " .. tostring(pos_row))
        break
      end
      table.insert(
        results,
        {
          declaring_node = declaration_node,
          dim = {
            s = {r = sRow, c = sCol},
            e = {r = eRow, c = eCol}
          },
          name = name,
          operator = op,
          type = type
        }
      )
    end
  end
  -- ulog("total nodes got: " .. tostring(#results))
  return results
end

M.nodes_at_cursor = function(query, default, bufnr, row, col)
  bufnr = bufnr or vim.api.nvim_get_current_buf()
  local ft = vim.api.nvim_buf_get_option(bufnr, "ft")
  if row == nil or col == nil then
    row, col = unpack(vim.api.nvim_win_get_cursor(0))
    row, col = row + 1, col + 1
  end
  local nodes = M.get_all_nodes(query, ft, default, bufnr, row, col)
  if nodes == nil then
    print("Unable to find any nodes.  Is your query correct?")
    return nil
  end

  nodes = M.sort_nodes(M.intersect_nodes(nodes, row, col))
  if nodes == nil or #nodes == 0 then
    print("Unable to find any nodes at pos. " .. tostring(row) .. ":" .. tostring(col))
    return nil
  end

  return nodes
end

return M