module godot.tools.generator.doc;

import godot.tools.generator.classes;
import godot.tools.generator.methods;
import godot.tools.generator.util;
import godot.util.string;

import std.stdio : writeln, writefln;
import std.string, std.range;
import std.algorithm.searching;
import std.exception : enforce;

import dxml.dom;
import dxml.util : stripIndent;

void parseClassDoc(GodotClass c, string xml) {
    string ddoc;
    auto dom = parseDOM!simpleXML(xml);

    enforce(dom.children.length == 1 && dom.children[0].name == "class",
        "Expected a single <class name=\"" ~ c.name.dType ~ "\"> in the doc XML");
    auto cDoc = dom.children[0];

    if (cDoc.hasChild("brief_description")) {
        auto bd = cDoc.child("brief_description");
        if (bd.childText) {
            ddoc ~= bd.childText;
            c.ddocBrief = bd.childText;
        }
    }

    if (cDoc.hasChild("description")) {
        auto fd = cDoc.child("description");
        if (fd.childText) {
            string t = fd.childText;
            // in case it starts with brief_description; only possible to detect if exactly the same, unfortunately
            t = t.chompPrefix(c.ddocBrief).strip;
            if (t) {
                if (ddoc)
                    ddoc ~= "\n\n";
                ddoc ~= t;
            }
        }
    }

    /// TODO: remove any */ from inside comment and change BBCode-style stuff to ddoc macros
    c.ddocBrief = c.ddocBrief.godotToDdoc;
    c.ddoc = ddoc.godotToDdoc;

    if (cDoc.hasChild("methods")) {
        auto methods = cDoc.child("methods");
        foreach (mDoc; methods.children) {
            auto index = c.methods.countUntil!"a.name == b"(mDoc.attribute("name"));
            if (index != -1) {
                parseMethodDoc(c.methods[index], mDoc);
            } else
                writefln("No method %s.%s", c.name.godotType, mDoc.attribute("name"));
        }
    }

    if (cDoc.hasChild("members")) {
        auto members = cDoc.child("members");
        foreach (mDoc; members.children) {
            auto index = c.properties.countUntil!"a.name == b"(mDoc.attribute("name"));
            if (index != -1) {
                parsePropertyDoc(c.properties[index], mDoc);
            } else
                writefln("No property %s.%s", c.name.godotType, mDoc.attribute("name"));
        }
    }

    if (cDoc.hasChild("constants")) {
        auto constants = cDoc.child("constants");
        foreach (ceDoc; constants.children) {
            /*
			auto cPtr = ceDoc.attribute("name") in c.constants;
			if(cPtr) c.ddocConstants[ceDoc.attribute("name")] = ceDoc.childText.godotToDdoc;
			
			if(!ceDoc.attribute("enum").empty)
			{
				auto index = c.enums.countUntil!"a.name == b"(ceDoc.attribute("enum"));
				if(index != -1) c.enums[index].ddoc[ceDoc.attribute("name")] = ceDoc.childText.godotToDdoc;
			}
			*/
        }
    }

    /// TODO: enums
}

void parseMethodDoc(GodotMethod m, DOMEntity!string mDoc) {
    if (mDoc.hasChild("description")) {
        auto fd = mDoc.child("description");
        if (fd.childText)
            m.ddoc = fd.childText.godotToDdoc;
    }
}

void parsePropertyDoc(GodotProperty p, DOMEntity!string pDoc) {
    p.ddoc = pDoc.childText.godotToDdoc;
}

// ddoc util functions

string godotToDdoc(string input) {
    import std.algorithm, std.string, std.regex;

    string ret = input;

    // handle [tags] like Godot's doc/tools/makerst.py

    ret = ret.replaceAll!((Captures!string s) {
        auto split = s[1].findSplit(".");
        if (split[1].empty)
            return "$(D " ~ s[1].snakeToCamel.escapeDType ~ ")";
        else
            return "$(D " ~ split[0].escapeGodotType ~ "." ~ split[2].snakeToCamel.escapeDType ~ ")";
    })(ctRegex!(`\[(?:method|member|signal|enum) (.+?)\]`));

    /// TODO: not D code, can't use --- blocks. Maybe the GDScript can be parsed and converted to D...
    ret = ret.replaceAll!((Captures!string s) => "\n" ~ s[1] ~ "\n")(
        ctRegex!(`\[codeblock\]([\s\S]*?)\[/codeblock\]`));

    ret = ret.replaceAll(ctRegex!`\[br\][ \t]*`, "$(BR)");

    ret = ret.replaceAll!((Captures!string s) => "$(" ~ s[1].toUpper ~ " " ~ s[2] ~ ")")(
        ctRegex!`\[([bui])\](.*?)\[/\1\]`);

    ret = ret.replaceAll!((Captures!string s) => "`" ~ s[1] ~ "`")(
        ctRegex!`\[code\](.*?)\[/code\]`);

    // fallback for [Class]
    ret = ret.replaceAll!((Captures!string s) => "$(D " ~ s[1].escapeGodotType ~ ")")(
        ctRegex!`\[(.+?)\]`);

    return ret;
}

// dxml util functions

string attribute(DOMEntity!string e, string name) {
    auto index = e.attributes.countUntil!"a.name == b"(name);
    if (index == -1)
        return null;
    return e.attributes[index].value;
}

bool hasChild(DOMEntity!string e, string name) {
    return e.children.countUntil!"a.name == b"(name) != -1;
}

DOMEntity!string child(DOMEntity!string e, string name) {
    auto index = e.children.countUntil!"a.name == b"(name);
    assert(index != -1);
    return e.children[index];
}

string childText(DOMEntity!string e) {
    auto index = e.children.countUntil!"a.type == b"(EntityType.text);
    if (index == -1)
        return null;
    return e.children[index].text.stripIndent;
}