bavbavhaus.net/pandoc/bavbavhaus.net.lua

local path = pandoc.path
local MetaList = pandoc.MetaList
local Link = pandoc.Link

INPUT_FILES = (function(prog)
    local insert = table.insert
    local input_files = {}
    local pfile = io.popen(prog)
    for filename in pfile:lines() do
        insert(input_files, filename)
    end
    pfile:close()
    return input_files
end)("ls -t *.md")

OUTPUT_FILES = (function(pattern)
    local split_extension = pandoc.path.split_extension
    local insert = table.insert
    local output_files = {}
    for _,filename in ipairs(INPUT_FILES) do
        local basename = split_extension(filename)
        insert(output_files, (pattern):format(basename))
    end
    return output_files
end)("public_html/%s.html")

print("[INFO] bavbavhaus.net: reading pages")
PAGES = (function()
    local pages = MetaList({})
    function pages:get(input_file)
        return self:find_if(function(page)
            return page["meta"]["input_file"] == input_file
        end)
    end
    local read = pandoc.read
    local ropts = pandoc.ReaderOptions({})
    for _,input_file in ipairs(INPUT_FILES) do
        print("[INFO] bavbavhaus.net: reading page: " .. input_file)
        local f = io.open(input_file)
        if not f then goto continue end
        pages:insert(read(f:read("a"), "markdown", ropts))
        f:close()
        ::continue::
    end
    return pages
end)()

print("[INFO] bavbavhaus.net: updating metadata")
do
    for i,page in ipairs(PAGES) do
        local input_file = INPUT_FILES[i]
        local output_file = OUTPUT_FILES[i]
        PAGES[i] = page:walk({
            Meta = function(meta)
                meta["input_file"] = input_file
                meta["output_file"] = output_file
                meta["url"] = input_file
                meta["title"] = meta["title"] or input_file
                return meta
            end,
        })
    end
end

print("[INFO] bavbavhaus.net: scanning pages for internal links")
BACKLINKS, FORELINKS = (function(pages)
    local MetaList = pandoc.MetaList
    local MetaMap = pandoc.MetaMap
    local backlinks = MetaMap({})
    local forelinks = MetaMap({})
    for i,page in ipairs(pages) do
        local input_file = page["meta"]["input_file"]
        page:walk({
            Link = function(link)
                if not PAGES:get(link.target) then return end
                if input_file == link.target then return end
                if not backlinks[link.target] then
                    backlinks[link.target] = MetaList({})
                end
                if not forelinks[input_file] then
                    forelinks[input_file] = MetaList({})
                end
                if not backlinks[link.target]:includes(input_file) then
                    backlinks[link.target]:insert(input_file)
                end
                if not forelinks[input_file]:includes(link.target) then
                    forelinks[input_file]:insert(link.target)
                end
            end
        })
    end
    return backlinks, forelinks
end)(PAGES)

print("[INFO] bavbavhaus.net: updating index page")
do
    local index = "index.md"
    FORELINKS[index] = MetaList({})
    for i,page in ipairs(PAGES) do
        if PAGES[i]["meta"]["input_file"] == index then goto continue end
        FORELINKS[index]:insert(page["meta"]["input_file"])
        ::continue::
    end
end

print("[INFO] bavbavhaus.net: updating link targets")
do
    function update_target(target)
        return ("%s.html#start"):format(path.split_extension(target))
    end
    for i,page in ipairs(PAGES) do
        PAGES[i] = page:walk({
            Meta = function(meta)
                meta["url"] = update_target(meta["url"])
                return meta
            end,
            Link = function(link)
                if not PAGES:get(link.target) then return end
                link.target = update_target(link.target)
                return Link(link.content, link.target)
            end
        })
    end
end

print("[INFO] bavbavhaus.net: processing citations")
do
    local csl = "pandoc/csl/chicago-fullnote-sl"
    local citeproc = pandoc.utils.citeproc
    for i,page in ipairs(PAGES) do
        PAGES[i] = page:walk({
            Meta = function(meta)
                meta["csl"] = csl
                return meta
            end,
            Pandoc = function(doc)
                return citeproc(doc)
            end
        })
    end
end

SITEMAP = (function()
    print("[INFO] bavbavhaus.net: generating sitemap")
    local sitemap = pandoc.MetaList({})
    for _,page in ipairs(PAGES) do
        local meta = page["meta"]
        sitemap:insert(Link(meta["title"], meta["url"]))
    end
    return sitemap
end)()

do
    print("[INFO] bavbavhaus.net: updating metadata (sitemap)")
    for i,page in ipairs(PAGES) do
        PAGES[i] = page:walk({
            Meta = function(meta)
                meta["sitemap"] = SITEMAP
                return meta
            end
        })
    end
end

do
    print("[INFO] bavbavhaus.net: writing partial pages")
    local write = pandoc.write
    local WriterOptions = pandoc.WriterOptions
    local compile = pandoc.template.compile
    local partial_template = (function(filepath)
        local f = io.open(filepath)
        if not f then return end
        local template = f:read("a")
        f:close()
        return compile(template)
    end)("pandoc/templates/bavbavhaus.net.partial.html5")
    local RawBlock = pandoc.RawBlock
    for i,page in ipairs(PAGES) do
        local input_file = page["meta"]["input_file"]
        if not BACKLINKS[input_file] then goto continue end
        local backlinks = MetaList({})
        for _,backlink in ipairs(BACKLINKS[input_file]) do
            backlinks:insert(RawBlock("html5", write(
                PAGES:get(backlink),
                "html5",
                WriterOptions({
                    identifier_prefix = "back/" .. backlink,
                    table_of_contents = true,
                    template = partial_template
                })
            )))
        end
        PAGES[i] = page:walk({
            Meta = function(meta)
                meta["backlinks"] = backlinks
                return meta
            end
        })
        ::continue::
    end
    for i,page in ipairs(PAGES) do
        local input_file = page["meta"]["input_file"]
        if not FORELINKS[input_file] then goto continue end
        local forelinks = MetaList({})
        for _,forelink in ipairs(FORELINKS[input_file]) do
            forelinks:insert(RawBlock("html5", write(
                PAGES:get(forelink),
                "html5",
                WriterOptions({
                    identifier_prefix = "fore/" .. forelink,
                    table_of_contents = true,
                    template = partial_template
                })
            )))
        end
        PAGES[i] = page:walk({
            Meta = function(meta)
                meta["forelinks"] = forelinks
                return meta
            end
        })
        ::continue::
    end
    print("[INFO] bavbavhaus.net: writing pages")
    local wopts = WriterOptions({
            table_of_contents = true,
            template = (function(filepath)
                local f = io.open(filepath)
                if not f then return end
                local template = f:read("a")
                f:close()
                return compile(template)
            end)("pandoc/templates/bavbavhaus.net.html5")
    })
    for _,page in ipairs(PAGES) do
        local f = io.open(page["meta"]["output_file"], "w")
        f:write(write(page, "html", wopts)) 
        f:close()
    end
end