require "proto"
require "lfs"
require "umake"
require "upath"

local upload = Object:clone()

-- Metaacls: path meta user call constr
-- #metaacl# / type User new recursive
-- #metaacl# / requires User new recursive
-- #metaacl# / generates User new recursive
-- #metaacl# / type User reset recursive
-- #metaacl# / requires User reset recursive
-- #metaacl# / generates User reset recursive
-- #metaacl# / type User delete recursive
-- #metaacl# / requires User delete recursive
-- #metaacl# / generates User delete recursive

function upload:invoke(session, request, response)

    local appendnewline = true   -- TODO initialize from a parameter

    -- data from textbox
    local content = request.params.blob
    if type(request.params.filename) == 'table' then
        -- file upload takes precedence
        content = request.params.filename.contents
        -- disable newline append for uploads
        appendnewline = false
    end

    local scm = session:scm_load(session.path)
    local thefile = scm:enter(session.path)

    if not request.params.id then
        assert(request.params.doctype, "ERANGE:No Document Type selected")
        -- create new file
        assert(not upath.exists(thefile), "EEXIST:File exists already")
        -- allow only someone with create permission
        assert(session:acl_check(session.path, "create"), "EACCESS:May not create content")

        -- with a new file a new acl might be established
        if request.params.aclenable == 'on' then
            session:acl_new(session.path, acl.parse(request.params.newacl))
        end

        -- recursively mkdir if permitted
        upath.ensuredir(session, scm.path, thefile)

        -- write content to file
        local file = io.open(thefile, "w")
        file:write(content)
        if appendnewline and content:sub(-1) ~= '\n' then
            file:write('\n')
        end
        file:close()

        -- TODO the whole operation might be rolled back, mkdir and file writing above included
        --      reasons: some abort on error parameter was given (refine errorrevert)
        --               spam check failed (TODO)

        -- first chance to commit a file    TODO before, after, never
        if request.params.commitctl == "before" then
            local comment = request.params.comment
            if not comment or comment == "" then
                comment = "Created "..thefile
            end
            scm:commit(session, thefile, comment)
        end

        local doctypes
        if type(request.params.doctype) == 'string' then
            -- got only one
            doctypes = {request.params.doctype}
        else
            -- got many
            doctypes = request.params.doctype
        end

        local types = {}

        for _,typename in ipairs(doctypes) do
            local type = session:type_load(typename)
            types[typename] = type
            if type:check(session.path) then
                type:register(session.path)
                type:discover(session.path)
            end
        end

        umake.recbuild(session, session.path, types)

        -- second chance to commit the file
        if request.params.commitctl == "after" then
            local comment = request.params.comment
            if not comment or comment == "" then
                comment = "Created "..thefile
            end
            scm:commit(session, thefile, comment)
        end
    else
        -- create new file
        assert(upath.exists(thefile), "EEXIST:File does not exist")

        -- edited existing file
        assert(session:acl_check(session.path, "edit"), "EACCESS:May not edit content")

        local tmpfile = os.tmpname ()
        local file = io.open(tmpfile, "w")
        file:write(content)
        if appendnewline and content:sub(-1) ~= '\n' then
            file:write('\n')
        end
        file:close()

        -- when the file currently present is not the one we started with then someone else edited the file meanwhile an a merge is required
        if request.params.id ~= scm:id(session.path) then
            local merged, conflict = scm:merge(request.params.id, tmpfile, thefile)

            if conflict then
                ustring.file_interpolate(
                    uwiki_conf.prefix .. uwiki_conf.docroot .. session.sys .. "form/edit.html",
                    {
                        login = session.user.login,
                        pass = session.user.pass,
                        id = scm:id(thefile),
                        message = "Conflict! Please fix",
                        path= session.path:sanitize('html'),
                        content= io.open(merged, "r"):read("*a"):sanitize('html')
                    },
                    function (str)
                        response:write(str)
                    end
                )

                os.remove(tmpfile)
                os.remove(merged)

                scm:leave()
                session:done()
                return response:finish()
            else
                -- merged without conflict, replace tmpfile with the merged file and proceed
                upath.move(merged, tmpfile)
            end
        end

        -- check what kind of edit the user did
        local types = {}
        for _,typename in pairs(session:meta_get(session.path, "type", "type")) do
            local type = session:type_load(typename)
            types[typename] = type

            -- ask the types about what kind of edit this was
            local editkind = type:diffkind(thefile, tmpfile)

            -- check if this edit type is allowed or rollback throw
            if editkind and not session:acl_check(session.path, "edit."..editkind) then
                os.remove(tmpfile)
                error("EACCESS:May not "..editkind.." content")
            end
        end

        -- ok lets replace the file
        upath.move(tmpfile, thefile)

        -- first chance to commit a file    TODO before, after, never
        if request.params.commitctl == "before" then
            local comment = request.params.comment
            if not comment or comment == "" then
                comment = "Edited "..thefile
            end
            scm:commit(session, thefile, comment)
        end

        for typename,type in pairs(types) do
            if type:check(session.path) then
                type:register(session.path)
                type:discover(session.path)
            end
        end

        umake.recbuild(session, session.path, types)

        -- second chance to commit the file
        if request.params.commitctl == "after" then
            local comment = request.params.comment
            if not comment or comment == "" then
                comment = "Edited "..thefile
            end
            scm:commit(session, thefile, comment)
        end
    end

    scm:leave()
    session:done()
    return response:finish()
end

return upload

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