koreader/frontend/docsettings.lua

local DocSettings = {}
-- lfs

function DocSettings:getHistoryPath(fullpath)
    local i = #fullpath - 1
    -- search for last slash
    while i > 0 do
        if fullpath:sub(i,i) == "/" then
            break
        end
        i = i - 1
    end
    -- construct path to configuration file in history dir
    local filename = fullpath:sub(i+1, -1)
    local basename = fullpath:sub(1, i)
    return "./history/["..basename:gsub("/","#").."] "..filename..".lua"
end

function DocSettings:getPathFromHistory(hist_name)
    -- 1. select everything included in brackets
    local s = string.match(hist_name,"%b[]")
    -- 2. crop the bracket-sign from both sides
    -- 3. and finally replace decorative signs '#' to dir-char '/'
    return string.gsub(string.sub(s,2,-3),"#","/")
end

function DocSettings:getNameFromHistory(hist_name)
    -- at first, search for path length
    local s = string.len(string.match(hist_name,"%b[]"))
    -- and return the rest of string without 4 last characters (".lua")
    return string.sub(hist_name, s+2, -5)
end

function DocSettings:open(docfile)
    local conf_path = nil
    if docfile == ".reader" then
        -- we handle reader setting as special case
        conf_path = "settings.reader.lua"
    else
        if lfs.attributes("./history","mode") ~= "directory" then
            lfs.mkdir("history")
        end
        conf_path = self:getHistoryPath(docfile)
    end
    -- construct settings obj
    local new = { file = conf_path, data = {} }
    local ok, stored = pcall(dofile, new.file)
    if not ok then
        -- try legacy conf path, for backward compatibility. this also
        -- takes care of reader legacy setting
        ok, stored = pcall(dofile, docfile..".kpdfview.lua")
    end
    if ok and stored then
        new.data = stored
    end
    return setmetatable(new, { __index = DocSettings})
end

function DocSettings:readSetting(key)
    return self.data[key]
end

function DocSettings:saveSetting(key, value)
    self.data[key] = value
end

function DocSettings:delSetting(key)
    self.data[key] = nil
end

function DocSettings:dump(data, max_lv)
    local out = {}
    self:_serialize(data, out, 0, max_lv)
    return table.concat(out)
end

-- simple serialization function, won't do uservalues, functions, loops
function DocSettings:_serialize(what, outt, indent, max_lv)
    if not max_lv then
        max_lv = math.huge
    end

    if indent > max_lv then
        return
    end

    if type(what) == "table" then
        local didrun = false
        table.insert(outt, "{")
        for k, v in pairs(what) do
            if didrun then
                table.insert(outt, ",")
            end
            table.insert(outt, "\n")
            table.insert(outt, string.rep("\t", indent+1))
            table.insert(outt, "[")
            self:_serialize(k, outt, indent+1, max_lv)
            table.insert(outt, "] = ")
            self:_serialize(v, outt, indent+1, max_lv)
            didrun = true
        end
        if didrun then
            table.insert(outt, "\n")
            table.insert(outt, string.rep("\t", indent))
        end
        table.insert(outt, "}")
    elseif type(what) == "string" then
        table.insert(outt, string.format("%q", what))
    elseif type(what) == "number" or type(what) == "boolean" then
        table.insert(outt, tostring(what))
    end
end

function DocSettings:flush()
    -- write a serialized version of the data table
    if not self.file then
        return
    end
    local f_out = io.open(self.file, "w")
    if f_out ~= nil then
        os.setlocale('C', 'numeric')
        local out = {"-- we can read Lua syntax here!\nreturn "}
        self:_serialize(self.data, out, 0)
        table.insert(out, "\n")
        f_out:write(table.concat(out))
        f_out:close()
    end
end

function DocSettings:close()
    self:flush()
end

return DocSettings