local st = require("util.stanza");

local pointer = require("util.jsonpointer");

local schema_t = {}

local function toboolean(s)

	if s == "true" or s == "1" then

		return true

	elseif s == "false" or s == "0" then

		return false

	elseif s then

		return true

	end

end

local function totype(t, s)

	if not s then

		return nil

	end

	if t == "string" then

		return s

	elseif t == "boolean" then

		return toboolean(s)

	elseif t == "number" or t == "integer" then

		return tonumber(s)

	end

end

local value_goes = {}

local function resolve_schema(schema, root)

	if type(schema) == "table" and schema["$ref"] and schema["$ref"]:sub(1, 1) == "#" then

		local referenced = pointer.resolve(root, schema["$ref"]:sub(2));

		if referenced ~= nil then

			return referenced

		end

	end

	return schema

end

local function unpack_propschema(propschema, propname, current_ns)

	local proptype = "string"

	local value_where = propname and "in_text_tag" or "in_text"

	local name = propname

	local namespace

	local prefix

	local single_attribute

	local enums

	if type(propschema) == "table" then

		proptype = propschema.type

	elseif type(propschema) == "string" then

		proptype = propschema

	end

	if proptype == "object" or proptype == "array" then

		value_where = "in_children"

	end

	if type(propschema) == "table" then

		local xml = propschema.xml

		if xml then

			if xml.name then

				name = xml.name

			end

			if xml.namespace and xml.namespace ~= current_ns then

				namespace = xml.namespace

			end

			if xml.prefix then

				prefix = xml.prefix

			end

			if proptype == "array" and xml.wrapped then

				value_where = "in_wrapper"

			elseif xml.attribute then

				value_where = "in_attribute"

			elseif xml.text then

				value_where = "in_text"

			elseif xml.x_name_is_value then

				value_where = "in_tag_name"

			elseif xml.x_single_attribute then

				single_attribute = xml.x_single_attribute

				value_where = "in_single_attribute"

			end

		end

		if propschema["const"] then

			enums = {propschema["const"]}

		elseif propschema["enum"] then

			enums = propschema["enum"]

		end

	end

	return proptype, value_where, name, namespace, prefix, single_attribute, enums

end

local parse_object

local parse_array

local function extract_value(s, value_where, proptype, name, namespace, prefix, single_attribute, enums)

	if value_where == "in_tag_name" then

		local c

		if proptype == "boolean" then

			c = s:get_child(name, namespace);

		elseif enums and proptype == "string" then

			for i = 1, #enums do

				c = s:get_child(enums[i], namespace);

				if c then

					break

				end

			end

		else

			c = s:get_child(nil, namespace);

		end

		if c then

			return c.name

		end

	elseif value_where == "in_attribute" then

		local attr = name

		if prefix then

			attr = prefix .. ":" .. name

		elseif namespace and namespace ~= s.attr.xmlns then

			attr = namespace .. "\1" .. name

		end

		return s.attr[attr]

	elseif value_where == "in_text" then

		return s:get_text()

	elseif value_where == "in_single_attribute" then

		local c = s:get_child(name, namespace)

		return c and c.attr[single_attribute]

	elseif value_where == "in_text_tag" then

		return s:get_child_text(name, namespace)

	end

end

function parse_object(schema, s, root)

	local out = {}

	schema = resolve_schema(schema, root)

	if type(schema) == "table" and schema.properties then

		for prop, propschema in pairs(schema.properties) do

			propschema = resolve_schema(propschema, root)

			local proptype, value_where, name, namespace, prefix, single_attribute, enums = unpack_propschema(propschema, prop, s.attr.xmlns)

			if value_where == "in_children" and type(propschema) == "table" then

				if proptype == "object" then

					local c = s:get_child(name, namespace)

					if c then

						out[prop] = parse_object(propschema, c, root);

					end

				elseif proptype == "array" then

					local a = parse_array(propschema, s, root);

					if a and a[1] ~= nil then

						out[prop] = a;

					end

				else

					error("unreachable")

				end

			elseif value_where == "in_wrapper" and type(propschema) == "table" and proptype == "array" then

				local wrapper = s:get_child(name, namespace);

				if wrapper then

					out[prop] = parse_array(propschema, wrapper, root);

				end

			else

				local value = extract_value(s, value_where, proptype, name, namespace, prefix, single_attribute, enums)

				out[prop] = totype(proptype, value)

			end

		end

	end

	return out

end

function parse_array(schema, s, root)

	local itemschema = resolve_schema(schema.items, root);

	local proptype, value_where, child_name, namespace, prefix, single_attribute, enums = unpack_propschema(itemschema, nil, s.attr.xmlns)

	local attr_name

	if value_where == "in_single_attribute" then

		value_where = "in_attribute";

		attr_name = single_attribute;

	end

	local out = {}

	if proptype == "object" then

		if type(itemschema) == "table" then

			for c in s:childtags(child_name, namespace) do

				table.insert(out, parse_object(itemschema, c, root));

			end

		else

			error("array items must be schema object")

		end

	elseif proptype == "array" then

		if type(itemschema) == "table" then

			for c in s:childtags(child_name, namespace) do

				table.insert(out, parse_array(itemschema, c, root));

			end

		end

	else

		for c in s:childtags(child_name, namespace) do

			local value = extract_value(c, value_where, proptype, attr_name or child_name, namespace, prefix, single_attribute, enums)

			table.insert(out, totype(proptype, value));

		end

	end

	return out

end

local function parse(schema, s)

	if schema.type == "object" then

		return parse_object(schema, s, schema)

	elseif schema.type == "array" then

		return parse_array(schema, s, schema)

	else

		error("top-level scalars unsupported")

	end

end

local function toxmlstring(proptype, v)

	if proptype == "string" and type(v) == "string" then

		return v

	elseif proptype == "number" and type(v) == "number" then

		return string.format("%g", v)

	elseif proptype == "integer" and type(v) == "number" then

		return string.format("%d", v)

	elseif proptype == "boolean" then

		return v and "1" or "0"

	end

end

local unparse

local function unparse_property(out, v, proptype, propschema, value_where, name, namespace, current_ns, prefix,

	single_attribute, root)

	if value_where == "in_attribute" then

		local attr = name

		if prefix then

			attr = prefix .. ":" .. name

		elseif namespace and namespace ~= current_ns then

			attr = namespace .. "\1" .. name

		end

		out.attr[attr] = toxmlstring(proptype, v)

	elseif value_where == "in_text" then

		out:text(toxmlstring(proptype, v))

	elseif value_where == "in_single_attribute" then

		assert(single_attribute)

		local propattr = {}

		if namespace and namespace ~= current_ns then

			propattr.xmlns = namespace

		end

		propattr[single_attribute] = toxmlstring(proptype, v)

		out:tag(name, propattr):up();

	else

		local propattr

		if namespace ~= current_ns then

			propattr = {xmlns = namespace}

		end

		if value_where == "in_tag_name" then

			if proptype == "string" and type(v) == "string" then

				out:tag(v, propattr):up();

			elseif proptype == "boolean" and v == true then

				out:tag(name, propattr):up();

			end

		elseif proptype == "object" and type(propschema) == "table" and type(v) == "table" then

			local c = unparse(propschema, v, name, namespace, nil, root);

			if c then

				out:add_direct_child(c);

			end

		elseif proptype == "array" and type(propschema) == "table" and type(v) == "table" then

			if value_where == "in_wrapper" then

				local c = unparse(propschema, v, name, namespace, nil, root);

				if c then

					out:add_direct_child(c);

				end

			else

				unparse(propschema, v, name, namespace, out, root);

			end

		else

			out:text_tag(name, toxmlstring(proptype, v), propattr)

		end

	end

end

function unparse(schema, t, current_name, current_ns, ctx, root)

	if root == nil then

		root = schema

	end

	if schema.xml then

		if schema.xml.name then

			current_name = schema.xml.name

		end

		if schema.xml.namespace then

			current_ns = schema.xml.namespace

		end

	end

	local out = ctx or st.stanza(current_name, {xmlns = current_ns})

	if schema.type == "object" then

		for prop, propschema in pairs(schema.properties) do

			propschema = resolve_schema(propschema, root)

			local v = t[prop]

			if v ~= nil then

				local proptype, value_where, name, namespace, prefix, single_attribute = unpack_propschema(propschema, prop, current_ns)

				unparse_property(out, v, proptype, propschema, value_where, name, namespace, current_ns, prefix, single_attribute, root)

			end

		end

		return out

	elseif schema.type == "array" then

		local itemschema = resolve_schema(schema.items, root)

		local proptype, value_where, name, namespace, prefix, single_attribute = unpack_propschema(itemschema, current_name, current_ns)

		for _, item in ipairs(t) do

			unparse_property(out, item, proptype, itemschema, value_where, name, namespace, current_ns, prefix, single_attribute, root)

		end

		return out

	end

end

return {parse = parse; unparse = unparse}