-------------------------------------------------------------------------------
-- Copyright (c) 2012 Sierra Wireless and others.
-- All rights reserved. This program and the accompanying materials
-- are made available under the terms of the Eclipse Public License v1.0
-- which accompanies this distribution, and is available at
-- http://www.eclipse.org/legal/epl-v10.html
--
-- Contributors:
--     Sierra Wireless - initial API and implementation
-------------------------------------------------------------------------------
-- A module containing generic function for test
-- @module testutil
local pp=require'metalua.pprint'
local apimodelbuilder = require 'models.apimodelbuilder'
local domhandler      = require 'domhandler'
local tablecompare    = require 'tablecompare'
local templateengine  = require 'templateengine'
local xml = require 'xml'

--
-- Loading template engine environment
--
for key, value in pairs(require 'template.utils') do
  templateengine.env[key] = value
end

local M = {}

local errorhandling = function (filename)
  local errorbuffer = {}
  return function (err, offset)
    local message = string.format(
      "An error occured while parsing html for %s at offset %d:%s\n",
      filename,
      offset,
      err
    )
    table.insert(errorbuffer, message)
  end, errorbuffer
end

---
-- Load a file in a string
-- @function [parent = #testutil] loadfile
-- @param filepath file absolute path
-- @return #string file content
function M.loadfile(filepath)

  local luafile, errormessage = io.open(filepath, 'r')
  assert(
    luafile,
    string.format('Unable to read from %s.\n%s', filepath, errormessage or '')
  )
  local filestring = luafile:read('*a')
  luafile:close()

  return filestring
end

---
-- Parse HTML in a table
-- @function [parent = #testutil] parsehtml
-- @param #string htmlstring html
-- @param #string filename File name to be display in case of a parsing error
-- @return table
-- @return status, errormessage in case of failure
function M.parsehtml(htmlstring, filename)

  -- Create parser for input html
  local handler = domhandler.createhandler()
  local xmlparser = xml.newparser(handler)
  xmlparser.options.stripWS = false
  local errorhandlingfunction, errormessages = errorhandling(filename)
  xmlparser.options.errorHandler = errorhandlingfunction

  -- Actual html parsing
  local status, pcallerror = pcall( function()
    xmlparser:parse(htmlstring)
  end)

  -- throw error with all message
  assert(status, string.format("%s\n%s\n%s",table.concat(errormessages), tostring(pcallerror),htmlstring))

  --throw failure
  if #errormessages ~= 0 then
    return nil, string.format("%s\n%s",table.concat(errormessages),htmlstring)
  end
  return handler.root
end

---
-- Compare HTML and return the result with a complete error message
-- @function [parent = #testutil] comparehtml
-- @param generatedtable Table to compare
-- @param referencetable Table expected
-- @param generatedhtml Html to compare
-- @parm referencehtml Html expected
-- @return status, formattederrormessage
function M.comparehtml(generatedtable, referencetable, generatedhtml, referencehtml)
  -- Check that they are equivalent
  local equivalent = tablecompare.compare(generatedtable, referencetable)
  if #equivalent > 0 then

    -- Compute which keys differs
    local differentkeys = tablecompare.diff(generatedtable, referencetable)
    local differentkeysstring = pp.tostring(differentkeys, {line_max=1})

    -- Convert table in formatted string
    local xmlformatter = require("xmlformatter")
    local htmlformattedstring= xmlformatter.xmltostring(generatedtable)
    local htmlformattedreferencestring = xmlformatter.xmltostring(referencetable)

    -- Create the diff
    local diffclass = java.require("diff.match.patch.diff_match_patch")
    local diff = diffclass:new()
    local differences = diff:diff_main(htmlformattedstring,htmlformattedreferencestring)
    diff:diff_cleanupSemantic(differences)

    -- Prettify the result
    local diffutil = java.require("org.eclipse.ldt.lua.tests.internal.utils.DiffUtil")
    local prettydiff = diffutil:diff_pretty_diff(differences)

    -- Formalise first table output
    local _ = '_'
    local line = _:rep(80)
    local stringdiff = string.format('%s\nString Diff \n%s\n%s', line, line, prettydiff)
    local generatedhtml   = string.format('%s\nGenerated HTML\n%s\n%s', line, line, generatedhtml)
    local referencehtml  = string.format('%s\nReference HTML\n%s\n%s', line, line, referencehtml)
    local tablediff = string.format('%s\nTable Diff \n%s\n%s', line, line, differentkeysstring)
    local generatedtable   = string.format('%s\nGenerated table\n%s\n%s', line, line, pp.tostring(generatedtable, {line_max=1}))
    local referencetable  = string.format('%s\nReference table\n%s\n%s', line, line, pp.tostring(referencetable, {line_max=1}))
    return nil, string.format('The generated HTML is not the same as the reference:\n%s\n%s\n%s\n%s\n%s\n%s',stringdiff, generatedhtml, referencehtml, tablediff, generatedtable, referencetable)
  end
  return true
end

return M