#include "dotgraph.hh"
#include "util.hh"
#include "store-api.hh"

#include <iostream>


using std::cout;

namespace nix {


static string dotQuote(std::string_view s)
{
    return "\"" + std::string(s) + "\"";
}


static string nextColour()
{
    static int n = 0;
    static string colours[] =
        { "black", "red", "green", "blue"
        , "magenta", "burlywood" };
    return colours[n++ % (sizeof(colours) / sizeof(string))];
}


static string makeEdge(const string & src, const string & dst)
{
    format f = format("%1% -> %2% [color = %3%];\n")
        % dotQuote(src) % dotQuote(dst) % dotQuote(nextColour());
    return f.str();
}


static string makeNode(const string & id, std::string_view label,
    const string & colour)
{
    format f = format("%1% [label = %2%, shape = box, "
        "style = filled, fillcolor = %3%];\n")
        % dotQuote(id) % dotQuote(label) % dotQuote(colour);
    return f.str();
}


#if 0
string pathLabel(const Path & nePath, const string & elemPath)
{
    return (string) nePath + "-" + elemPath;
}


void printClosure(const Path & nePath, const StoreExpr & fs)
{
    PathSet workList(fs.closure.roots);
    PathSet doneSet;

    for (PathSet::iterator i = workList.begin(); i != workList.end(); ++i) {
        cout << makeEdge(pathLabel(nePath, *i), nePath);
    }

    while (!workList.empty()) {
        Path path = *(workList.begin());
        workList.erase(path);

        if (doneSet.insert(path).second) {
            ClosureElems::const_iterator elem = fs.closure.elems.find(path);
            if (elem == fs.closure.elems.end())
                throw Error(format("bad closure, missing path '%1%'") % path);

            for (StringSet::const_iterator i = elem->second.refs.begin();
                 i != elem->second.refs.end(); ++i)
            {
                workList.insert(*i);
                cout << makeEdge(pathLabel(nePath, *i), pathLabel(nePath, path));
            }

            cout << makeNode(pathLabel(nePath, path),
                symbolicName(path), "#ff0000");
        }
    }
}
#endif


void printDotGraph(ref<Store> store, StorePathSet && roots)
{
    StorePathSet workList(std::move(roots));
    StorePathSet doneSet;

    cout << "digraph G {\n";

    while (!workList.empty()) {
        auto path = std::move(workList.extract(workList.begin()).value());

        if (!doneSet.insert(path.clone()).second) continue;

        cout << makeNode(std::string(path.to_string()), path.name(), "#ff0000");

        for (auto & p : store->queryPathInfo(path)->references) {
            if (p != path) {
                workList.insert(p.clone());
                cout << makeEdge(std::string(p.to_string()), std::string(p.to_string()));
            }
        }

#if 0
        StoreExpr ne = storeExprFromPath(path);

        string label, colour;

        if (ne.type == StoreExpr::neDerivation) {
            for (PathSet::iterator i = ne.derivation.inputs.begin();
                 i != ne.derivation.inputs.end(); ++i)
            {
                workList.insert(*i);
                cout << makeEdge(*i, path);
            }

            label = "derivation";
            colour = "#00ff00";
            for (StringPairs::iterator i = ne.derivation.env.begin();
                 i != ne.derivation.env.end(); ++i)
                if (i->first == "name") label = i->second;
        }

        else if (ne.type == StoreExpr::neClosure) {
            label = "<closure>";
            colour = "#00ffff";
            printClosure(path, ne);
        }

        else abort();

        cout << makeNode(path, label, colour);
#endif
    }

    cout << "}\n";
}


}