--- Note: some of the functions/code coped from treesitter/refactor/navigation.lua and may be modified
-- to fit in navigator.lua
local gui = require('navigator.gui')
local fn = vim.fn
local lru = require('navigator.lru').new(500, 1024 * 1024)

local ok, ts_locals = pcall(require, 'nvim-treesitter.locals')

if not ok then
  error('treesitter not installed')
  return nil
end

local parsers = require('nvim-treesitter.parsers')
local utils = require('nvim-treesitter.utils')
local locals = require('nvim-treesitter.locals')
local ts_utils = require('nvim-treesitter.ts_utils')
local api = vim.api
local util = require('navigator.util')
local M = {}

local cwd = vim.loop.cwd()
local log = require('navigator.util').log
local lerr = require('navigator.util').error
local trace = require('navigator.util').trace

local get_icon = function(kind)
  if kind == nil or _NgConfigValues.icons.match_kinds[kind] == nil then
    return _NgConfigValues.icons.treesitter_defult
  else
    return _NgConfigValues.icons.match_kinds[kind]
  end
end
-- require'navigator.treesitter'.goto_definition()
function M.goto_definition(bufnr)
  bufnr = bufnr or api.nvim_get_current_buf()
  local node_at_point = ts_utils.get_node_at_cursor()

  if not node_at_point then
    return
  end

  local definition = locals.find_definition(node_at_point, bufnr)

  if definition ~= node_at_point then
    log('def found:', definition:range())
    ts_utils.goto_node(definition)
  end
end

local function node_is_definination(node)
  if node:parent() == nil then
    return false
  end
  local nd_type = node:parent():type()
  local decl = { 'short_var_declaration', 'short_var_declaration', 'declaration' }

  if vim.tbl_contains(decl, nd_type) then
    return true
  end

  if node:parent():parent() == nil then
    return false
  end

  nd_type = node:parent():parent():type()
  if vim.tbl_contains(decl, nd_type) then
    return true
  end

  return false
end

-- use lsp range to find def
function M.find_definition(range, bufnr)
  if not range or not range.start then
    lerr('find_def incorrect range', range)
    return
  end
  bufnr = bufnr or api.nvim_get_current_buf()
  local parser = parsers.get_parser(bufnr)
  local symbolpos = { range.start.line, range.start.character } -- +1 or not?
  local root = ts_utils.get_root_for_position(range.start.line, range.start.character, parser)
  if not root then
    return
  end
  local node_at_point = root:named_descendant_for_range(symbolpos[1], symbolpos[2], symbolpos[1], symbolpos[2])
  if not node_at_point then
    lerr('no node at cursor')
    return
  end

  local definition = locals.find_definition(node_at_point, bufnr)
  if definition ~= node_at_point then -- NOTE: it may not worksfor some of languages. if def not found, ts
    -- returns current node. if your node is def, then it also return self... then I have no idea weather it is
    -- def or not
    trace('info: def found:', definition:range(), definition:type())
    local r, c = definition:range()
    return { start = { line = r, character = c } }
  elseif node_is_definination(node_at_point) then
    trace('declaraction here ', definition:type())
    local r, c = definition:range()
    return { start = { line = r, character = c } }
  else
    trace('error: def not found in ', bufnr, definition:range(), definition:type(), definition:parent():type())
  end
end

--- Get definitions of bufnr (unique and sorted by order of appearance).
--- This function copy from treesitter/refactor/navigation.lua
local function get_definitions(bufnr)
  local local_nodes = ts_locals.get_locals(bufnr)
  -- Make sure the nodes are unique.
  local nodes_set = {}
  for _, loc in ipairs(local_nodes) do
    if loc.definition then
      ts_locals.recurse_local_nodes(loc.definition, function(_, node, _, match)
        -- lua doesn't compare tables by value,
        -- use the value from byte count instead.
        local _, _, start = node:start()
        nodes_set[start] = { node = node, type = match or '' }
      end)
    end
  end

  -- Sort by order of appearance.
  local definition_nodes = vim.tbl_values(nodes_set)
  table.sort(definition_nodes, function(a, b)
    local _, _, start_a = a.node:start()
    local _, _, start_b = b.node:start()
    return start_a < start_b
  end)

  return definition_nodes
end

local function prepare_node(node, kind)
  local matches = {}
  kind = kind or node.type
  if node.node then
    table.insert(matches, { kind = get_icon(kind), def = node.node, type = kind })
  else
    for name, item in pairs(node) do
      vim.list_extend(matches, prepare_node(item, name))
    end
  end
  return matches
end

local function get_scope(type, source)
  local current = source
  local next = ts_utils.get_next_node(source)
  local parent = current:parent()
  trace(source:type(), source:range(), parent)

  if type == 'method' or type == 'function' and parent ~= nil then
    trace(parent:type(), parent:range())
    -- a function name
    if parent:type() == 'function_name' then
      -- up one level
      return parent:parent(), true
    end
    if parent:type() == 'function_name_field' then
      return parent:parent():parent(), true
    end

    -- for C++
    local n = source
    for _ = 1, 4, 1 do
      if n == nil or n:parent() == nil then
        break
      end
      n = n:parent()
      if n:type() == 'function_definition' then
        return n, true
      end
    end
    return parent, true
  end

  if type == 'var' and next ~= nil then
    if next:type() == 'function' or next:type() == 'arrow_function' or next:type() == 'function_definition' then
      trace(current:type(), current:range())
      return next, true
    elseif parent:type() == 'function_declaration' then
      return parent, true
    else
      trace(source, source:type())
      return source, false
    end
  else
    -- M.fun1 = function() end
    -- lets work up and see next node, lua
    local n = source
    for _ = 1, 4, 1 do
      if n == nil or n:parent() == nil then
        break
      end
      n = n:parent()
      next = ts_utils.get_next_node(n)
      if next ~= nil and next:type() == 'function_definition' then
        return next, true
      end
    end
  end

  if source:type() == 'type_identifier' then
    return source:parent(), true
  end
end

local function get_smallest_context(source)
  local scopes = ts_locals.get_scopes()
  for key, value in pairs(scopes) do
    trace(key, value)
  end
  local current = source
  while current ~= nil and not vim.tbl_contains(scopes, current) do
    current = current:parent()
  end
  if current ~= nil then
    return current, true
  end
  -- if source:type() == "identifier" then return get_var_context(source) end
end

local lsp_reference = require('navigator.dochighlight').goto_adjent_reference

function M.goto_adjacent_usage(bufnr, delta)
  local opt = { forward = true }
  -- log(delta)
  if delta < 0 then
    opt.forward = false
  end
  bufnr = bufnr or api.nvim_get_current_buf()
  local node_at_point = ts_utils.get_node_at_cursor()
  if not node_at_point then
    lsp_reference(opt)
    return
  end

  local def_node, scope = ts_locals.find_definition(node_at_point, bufnr)
  local usages = ts_locals.find_usages(def_node, scope, bufnr)

  local index = utils.index_of(usages, node_at_point)
  if not index then
    lsp_reference(opt)
    return
  end

  local target_index = (index + delta + #usages - 1) % #usages + 1
  ts_utils.goto_node(usages[target_index])
end

function M.goto_next_usage(bufnr)
  return M.goto_adjacent_usage(bufnr, 1)
end
function M.goto_previous_usage(bufnr)
  return M.goto_adjacent_usage(bufnr, -1)
end

local function key(fname, filter)
  return fname .. vim.inspect(filter)
end

local function get_all_nodes(bufnr, filter, summary)
  local fname = vim.fn.expand('%:p:f')
  local uri = vim.uri_from_fname(fname)
  if bufnr ~= 0 then
    uri = vim.uri_from_bufnr(bufnr)
    fname = vim.uri_to_fname(uri)
  end

  local ftime = vim.fn.getftime(fname)

  local hash = key(fname, filter)

  local result = lru:get(hash)
  if result ~= nil and result.ftime == ftime then
    log('get data from cache')
    return result.nodes, result.length
  end

  if result ~= nil and result.ftime ~= ftime then
    lru:delete(hash)
  end

  trace(bufnr, filter, summary)
  if not bufnr then
    vim.notify('get_all_node invalide bufnr', vim.lsp.log_levels.WARN)
  end
  summary = summary or false
  local ft = vim.api.nvim_buf_get_option(bufnr, 'filetype')
  if not parsers.has_parser() then
    if not require('navigator.lspclient.clients').ft_disabled(ft) then
      vim.notify('ts not loaded ' .. ft, vim.lsp.log_levels.Debug)
    end
    return {}
  end

  local path_sep = require('navigator.util').path_sep()
  local path_cur = require('navigator.util').path_cur()
  local display_filename = fname:gsub(cwd .. path_sep, path_cur, 1)

  local all_nodes = {}
  -- Support completion-nvim customized label map
  -- local customized_labels = vim.g.completion_customize_lsp_label or {}

  -- Force some types to act like they are parents
  -- instead of neighbors of the next nodes.
  local containers = {
    ['function'] = true,
    ['local_function'] = true,
    ['arrow_function'] = true,
    ['type'] = true,
    ['class'] = true,
    -- ['var'] = true,
    ['struct'] = true,
    ['method'] = true,
  }

  -- check and load buff

  local should_unload = false
  if not vim.api.nvim_buf_is_loaded(bufnr) then
    should_unload = true
    vim.fn.bufload(bufnr)
  end

  -- Step 2 find correct completions
  local length = 10
  local parents = {} -- stack of nodes a clever algorithm from treesiter refactor @Santos Gallegos
  local loaded_symbol = {}
  for _, def in ipairs(get_definitions(bufnr)) do
    local n = #parents
    for i = 1, n do
      local index = n + 1 - i
      local parent_def = parents[index]
      log(parent_def.type, parent_def.node:type(), vim.treesitter.get_node_text(parent_def.node, bufnr))
      log(def.node:type(), vim.treesitter.get_node_text(def.node, bufnr))
      if
        ts_utils.is_parent(parent_def.node, def.node)
        or (
          containers[parent_def.type]
          and (
            ts_utils.is_parent(parent_def.node:parent(), def.node)
            or (
              parent_def.node:parent():type():find('dot_index')
              and ts_utils.is_parent(parent_def.node:parent():parent(), def.node)
            )
          )
        )
      then
        log('is parent', i, index)
        break
      else
        log('leave node', i, index)
        parents[index] = nil
      end
    end
    parents[#parents + 1] = def
    local nodes = prepare_node(def)
    local item = {}

    for _, node in ipairs(nodes) do
      item.kind = node.kind
      item.type = node.type

      if filter ~= nil and not filter[item.type] then
        trace(item.type, item.kind)
        goto continue
      end

      if item.type == 'associated' then
        goto continue
      end
      local tsdata = node.def

      if node.def == nil then
        goto continue
      end
      item.node_text = vim.treesitter.get_node_text(tsdata, bufnr)
      local scope, is_func

      if summary then
        scope, is_func = get_scope(item.type, tsdata)
      else
        scope, is_func = get_smallest_context(tsdata)
      end
      if is_func then
        -- hack for lua and maybe other language aswell
        local parent = tsdata:parent()
        if parent ~= nil then
          log(parent:type(), vim.treesitter.get_node_text(parent, bufnr), item.node_text, item.type)
        end
        if
          parent ~= nil
          and (
            parent:type() == 'function_name'
            -- or parent:type() == 'function'
            -- or parent:type() == 'function_declaration' -- this bring in too much info
            or parent:type() == 'method_name'
            or parent:type() == 'function_name_field'
          )
        then
          -- replace function name
          item.node_text = vim.treesitter.get_node_text(parent, bufnr)
          local cut = item.node_text:find('[\n\r]')
          if cut then
            item.node_text = item.node_text:sub(1, cut - 1)
          end
          log(parent:type(), item.node_text)
        end
      end

      trace(item.node_text, item.kind, item.type)
      if scope ~= nil then
        if not is_func and summary then
          log(item.node_text, item.type)
          goto continue
        end
        item.node_scope = ts_utils.node_to_lsp_range(scope)
      end
      if item.node_text == '_' then
        goto continue
      end
      if summary then
        if item.node_scope ~= nil then
          table.insert(all_nodes, item)
        end

        if item.node_scope then
          trace(
            item.type,
            tsdata:type(),
            item.node_text,
            item.kind,
            'range',
            item.node_scope.start.line,
            item.node_scope['end'].line
          ) -- set to log if need to trace result
        end
        goto continue
      end

      item.range = ts_utils.node_to_lsp_range(tsdata)
      local start_line_node, _, _ = tsdata:start()

      local line_text = api.nvim_buf_get_lines(bufnr, start_line_node, start_line_node + 1, false)[1] or ''
      item.full_text = vim.trim(line_text)

      item.full_text = item.full_text:gsub('%s*[%[%(%{]*%s*$', '')
      item.uri = uri
      item.name = node.node_text
      item.filename = fname
      item.display_filename = display_filename
      item.lnum, item.col, _ = def.node:start()
      item.lnum = item.lnum + 1
      item.col = item.col + 1
      local indent = ''
      if #parents > 1 then
        indent = string.rep('  ', #parents - 1) .. ' '
      end
      item.indent = indent
      item.indent_level = #parents -- maybe use real indent level ?
      if item.indent_level <= 1 then
        local sp = string.match(line_text, '(%s*)')
        log(line_text, #sp)
        if sp then
          local indent_level = #sp / (vim.o.shiftwidth or 4) + 1
          item.indent_level = math.max(item.indent_level, indent_level)
        end
      end
      if #parents > 0 then
        log(parents[1].type, vim.treesitter.get_node_text(parents[1].node, bufnr))
        if parents[2] then
          log(parents[2].type, vim.treesitter.get_node_text(parents[2].node, bufnr))
        end
      else
        log('root node')
      end
      if #all_nodes >= 1 then
        all_nodes[#all_nodes].next_indent_level = #parents
      end

      item.text = string.format(' %s %s%-10s\t %s', item.kind, indent, item.node_text, item.full_text)
      if #item.text > length then
        length = #item.text
      end
      if
        loaded_symbol[item.node_text .. item.kind] == nil
        or not util.range_inside(loaded_symbol[item.node_text .. item.kind], item.node_scope)
      then
        table.insert(all_nodes, item)
        loaded_symbol[item.node_text .. item.kind] = item.node_scope
      end
      ::continue::
    end
  end
  trace(all_nodes)
  local nd = { nodes = all_nodes, ftime = vim.fn.getftime(fname), length = length }
  lru:set(hash, nd)
  if should_unload then
    vim.api.nvim_buf_delete(bufnr, { unload = true })
  end
  return all_nodes, length
end

function M.buf_func(bufnr)
  local ft = vim.api.nvim_buf_get_option(bufnr, 'buftype')
  if vim.api.nvim_buf_get_option(bufnr, 'buftype') == 'nofile' then
    return
  end
  if not ok or ts_locals == nil then
    error('treesitter not loaded: ' .. ft)
    return
  end

  bufnr = bufnr or api.nvim_get_current_buf()

  local all_nodes, width = get_all_nodes(bufnr, {
    ['function'] = true,
    ['var'] = true,
    ['method'] = true,
    ['class'] = true,
    ['type'] = true,
  }, true)
  if #all_nodes < 1 then
    trace('no node found for ', bufnr) -- set to log
    return
  end

  if all_nodes[1].node_scope then
    table.sort(all_nodes, function(i, j)
      if i.node_scope and j.node_scope then
        if i.node_scope['end'].line == j.node_scope['end'].line then
          return i.node_scope.start.line > j.node_scope.start.line
        else
          return i.node_scope['end'].line < j.node_scope['end'].line
        end
      end
      return false
    end)
  else
    table.sort(all_nodes, function(i, j)
      if i.range and j.range then
        if i.range['end'].line == j.range['end'].line then
          return i.range.start.line > j.range.start.line
        else
          return i.range['end'].line < j.range['end'].line
        end
      end
      return false
    end)
  end

  return all_nodes, width
end

function M.all_ts_nodes(bufnr)
  if ts_locals == nil then
    error('treesitter not loaded')
    return
  end

  local bufnr = bufnr or api.nvim_get_current_buf()
  local all_nodes, width = get_all_nodes(bufnr)
  return all_nodes, width
end

function M.side_panel()
  Panel = require('guihua.panel')
  local bufnr = api.nvim_get_current_buf()
  local p = Panel:new({
    header = 'treesitter',
    render = function(b)
      log('render for ', bufnr, b)
      return require('navigator.treesitter').all_ts_nodes(b)
    end,
  })
  p:open(true)
end

function M.buf_ts()
  local all_nodes, width = M.all_ts_nodes()
  local bufnr = api.nvim_get_current_buf()
  local ft = vim.api.nvim_buf_get_option(bufnr, 'ft')
  local listview = gui.new_list_view({
    items = all_nodes,
    prompt = true,
    ft = ft,
    rawdata = true,
    height = 0.62,
    preview_height = 0.12,
    width = width + 10,
    api = _NgConfigValues.icons.treesitter_defult,
  })
  return listview, all_nodes, width
end

M.get_all_nodes = get_all_nodes

function M.bufs_ts()
  if ts_locals == nil then
    error('treesitter not loaded')
    return
  end
  local bufs = vim.api.nvim_list_bufs()
  local ts_opened = {}
  local max_length = 10
  for _, buf in ipairs(bufs) do
    local bname = vim.fn.bufname(buf)
    if #bname > 0 and not util.exclude(bname) then
      if vim.api.nvim_buf_is_loaded(buf) then
        local all_nodes, length = get_all_nodes(buf)
        if all_nodes ~= nil then
          if length > max_length then
            max_length = length
          end
          vim.list_extend(ts_opened, all_nodes)
        end
      end
    end
  end
  if #ts_opened > 1 then
    trace(ts_opened)

    local ft = vim.api.nvim_buf_get_option(0, 'ft')
    gui.new_list_view({
      items = ts_opened,
      prompt = true,
      ft = ft,
      height = 0.62,
      preview_height = 0.12,
      width = max_length + 10,
      api = _NgConfigValues.icons.treesitter_defult,
    })
  end
end

local function node_in_range(parser, range)
  for _, child in pairs(parser._children) do
    if child:contains(range) then
      local result = node_in_range(child, range)
      if not vim.tbl_contains({ vim.bo.filetype }, result:lang()) then
        -- log("not correct tree embedded or comment?", result:lang())
        return parser
      end
      return result
    end
  end
  return parser
end

function M.get_node_at_line(lnum)
  if not parsers.has_parser() then
    return
  end

  -- Get the position for the queried node
  if lnum == nil then
    local cursor = api.nvim_win_get_cursor(0)
    lnum = cursor[1]
  end
  local first_non_whitespace_col = fn.match(fn.getline(lnum), '\\S')
  local range = { lnum - 1, first_non_whitespace_col, lnum - 1, first_non_whitespace_col }

  -- Get the language tree with nodes inside the given range
  local root = parsers.get_parser()
  local ts_tree = node_in_range(root, range)
  -- log(ts_tree:trees())
  local tree = ts_tree:trees()[1]

  local node = tree:root():named_descendant_for_range(unpack(range))

  -- trace(node, node:type()) -- log all lines and all nodes
  return node
end

local usage_namespace = vim.api.nvim_create_namespace('nvim-treesitter-usages')

function M.highlight_usages(bufnr)
  M.clear_usage_highlights(bufnr)

  local node_at_point = ts_utils.get_node_at_cursor()
  local references = locals.get_references(bufnr)

  if not node_at_point or not vim.tbl_contains(references, node_at_point) then
    return
  end

  local def_node, scope = locals.find_definition(node_at_point, bufnr)
  local usages = locals.find_usages(def_node, scope, bufnr)

  for _, usage_node in ipairs(usages) do
    if usage_node ~= node_at_point then
      ts_utils.highlight_node(usage_node, bufnr, usage_namespace, 'TSDefinitionUsage')
    end
  end

  if def_node ~= node_at_point then
    ts_utils.highlight_node(def_node, bufnr, usage_namespace, 'TSDefinition')
  end
end

function M.clear_usage_highlights(bufnr)
  api.nvim_buf_clear_namespace(bufnr, usage_namespace, 0, -1)
end

function M.get_node_at_pos(pos, parser)
  -- local cursor = api.nvim_win_get_cursor(winnr or 0)
  local cursor_range = { pos[1], pos[2] }

  log(cursor_range)
  local root = ts_utils.get_root_for_position(unpack(cursor_range), parser)

  if not root then
    return
  end

  local node = root:named_descendant_for_range(cursor_range[1], cursor_range[2], cursor_range[1], cursor_range[2])
  log(node, node:range())
  return node
end

function M.get_node_scope(node)
  -- local
  local n = node
  if n == nil then
    return 0, 0, 0, 0
  end
  local sr, sc, er, ec = n:range()

  log(n:range())
  for _ = 1, 6 do
    if n == nil then
      return 0, 0, 0, 0
    end

    local nsr, nsc, ner, nec = n:range()

    if nsr < sr then
      log(sr, er)
      break
    end
    sr, sc, er, ec = nsr, nsc, ner, nec
    if n:parent() then
      n = n:parent()
    end
  end

  return sr, sc, er, ec
end

return M