testhtml.lua

-- PetitRobert2007 HTML cleanup

local Screen = require("device").screen
local logger=require("logger")
local util=require("util")



-- From http://lua-users.org/wiki/LuaXml
-- Pure lua XML parsing

local function parseargs(s)
    local arg = {}
    string.gsub(s, "([%-%w]+)=([\"'])(.-)%2", function (w, _, a) arg[w] = a end)
    return arg
end
    
local function collect(s)
    local stack = {}
    local top = {}
    table.insert(stack, top)
    local ni,c,label,xarg, empty
    local i, j = 1, 1
    while true do
        --  s="toto</b toto='tutu'/>titi"
        --  print( string.find(s, "<(%/?)([%w:]+)(.-)(%/?)>", 1))
        --  5       21      /       b        toto='tutu'    /
        ni,j,c,label,xarg, empty = string.find(s, "<(%/?)([%w:]+)(.-)(%/?)>", i)
        if not ni then break end

        -- If we wouldn't trust label cases
        -- if label then label = label:lower() end

        local text = string.sub(s, i, ni-1)
        -- me: keep empty spaces
        -- if not string.find(text, "^%s*$") then
        if text ~= "" then
            table.insert(top, text)
        end

        if label:lower() == "hr" then empty = "/" end

        if empty == "/" then    -- empty element tag
            table.insert(top, {label=label, xarg=parseargs(xarg), empty=1})
        elseif c == "" then     -- start tag

            top = {label=label, xarg=parseargs(xarg)}
            table.insert(stack, top)     -- new level

        else    -- end tag

          local z=0
          while #stack > 1 do -- close all non matching label

            local toclose = table.remove(stack)    -- remove top
            top = stack[#stack]


              z = z + 1
              if toclose and toclose.label == label then -- closing matching tag
                table.insert(top, toclose)
                break
              else
                -- logger.warn("got", label, "closing non-matching", toclose.label, z)
                table.insert(top, toclose)
              end

          end

            if #stack < 1 then
                logger.warn("PetitRobert2017: stack is empty")
            end

        end
        i = j+1
    end

    local text = string.sub(s, i)
    -- me: keep empty spaces
    -- if not string.find(text, "^%s*$") then
    if text ~= "" then
        table.insert(stack[#stack], text)
    end

    if #stack > 1 then
        logger.warn("PetitRobert2017: stack at end has multiple elements:", #stack)
        return stack
    end
    return stack[1]
end

-- MuPDF expects XHTML. In XHTML, all tags and attributes should be lowercase
local function serialize(elem, colored)
    local s = {}
    if type(elem) == "string" then
        table.insert(s, elem) -- .." ")
    elseif type(elem) == "table" then
        if elem.label then
            if elem.label == "DIV" then table.insert(s, "<div></div>") end -- fix A/I/1 div
            table.insert(s, "<")
            table.insert(s, elem.label:lower())
            if elem.label:lower() == "a" and not colored then
                table.insert(s, ' style="color: black"')
            end
            if elem.xarg and type(elem.xarg) == "table" then
                for attr, value in pairs(elem.xarg) do
                    -- MuPDF needs lowercase href to consider it a link...
                    if elem.label:lower() == "a" and attr:lower() == "href" then
                        attr = "href"
                    end
                    if elem.label == "DIV" and attr == "style" then -- fix A/I/1 div
                        if not value:find("border: solid") then
                            value = value .. "; display: inline"
                        end
                    end
                    if attr == "style" and not colored then
                        -- colored stuff is displayed at less readable light grey: get black
                        value = value:gsub('background%-color:', 'zbgcol:')
                        value = value:gsub('color: navy', 'color: black')
                        value = value:gsub('color: red', 'color: black')
                        -- main meaning in blue => bold black
                        value = value:gsub('color: rgb%(51,51,153%); font%-style: normal; font%-weight: normal', 'color: black; font-style: normal; font-weight: bold')
                        value = value:gsub(" #%w%w%w%w%w%w", " black")
                        value = value:gsub(" rgb%(.-%)", " black")
                    end
                    table.insert(s, string.format(' %s="%s"', attr:lower(), value))
                end
            end
            if elem.empty then
                table.insert(s, "/>")
            else
                table.insert(s, ">")
            end
        end
        for _, subelem in ipairs(elem) do
            table.insert(s, serialize(subelem, colored))
        end
        if elem.label and not elem.empty then
            table.insert(s, string.format('</%s>', elem.label:lower()))
        end
    end
    return table.concat(s)
end

return function(html)
    html = html:gsub('<c c=\"', '<font color=\"')
    html = html:gsub('</c>', '</font>')
    html = html:gsub('<c>', '<font>')
    local colored = Screen:isColorEnabled()
    local stack = collect(html)
    
    html = serialize(stack, colored)
--    logger.warn("SERIALIZED:", html)

    f = io.open("/tmp/outdict.html", "w")
    f:write(html)
    f:close()

    return html
end