#include "progress-bar.hh"
#include "util.hh"
#include "sync.hh"
#include "store-api.hh"

#include <map>
#include <atomic>

namespace nix {

static std::string getS(const std::vector<Logger::Field> & fields, size_t n)
{
    assert(n < fields.size());
    assert(fields[n].type == Logger::Field::tString);
    return fields[n].s;
}

static uint64_t getI(const std::vector<Logger::Field> & fields, size_t n)
{
    assert(n < fields.size());
    assert(fields[n].type == Logger::Field::tInt);
    return fields[n].i;
}

/* Truncate a string to 'width' printable characters. ANSI escape
   sequences are copied but not included in the character count. Also,
   tabs are expanded to spaces. */
static std::string ansiTruncate(const std::string & s, int width)
{
    if (width <= 0) return s;

    std::string t;
    size_t w = 0;
    auto i = s.begin();

    while (w < (size_t) width && i != s.end()) {
        if (*i == '\e') {
            t += *i++;
            if (i != s.end() && *i == '[') {
                t += *i++;
                while (i != s.end() && (*i < 0x40 || *i > 0x7e)) {
                    t += *i++;
                }
                if (i != s.end()) t += *i++;
            }
        }

        else if (*i == '\t') {
            t += ' '; w++;
            while (w < (size_t) width && w & 8) {
                t += ' '; w++;
            }
        }

        else {
            t += *i++; w++;
        }
    }

    return t;
}

class ProgressBar : public Logger
{
private:

    struct ActInfo
    {
        std::string s, lastLine, phase;
        ActivityType type = actUnknown;
        uint64_t done = 0;
        uint64_t expected = 0;
        uint64_t running = 0;
        uint64_t failed = 0;
        std::map<ActivityType, uint64_t> expectedByType;
        bool visible = true;
        ActivityId parent;
    };

    struct ActivitiesByType
    {
        std::map<ActivityId, std::list<ActInfo>::iterator> its;
        uint64_t done = 0;
        uint64_t expected = 0;
        uint64_t failed = 0;
    };

    struct State
    {
        std::list<ActInfo> activities;
        std::map<ActivityId, std::list<ActInfo>::iterator> its;

        std::map<ActivityType, ActivitiesByType> activitiesByType;

        uint64_t filesLinked = 0, bytesLinked = 0;

        uint64_t corruptedPaths = 0, untrustedPaths = 0;

        bool active = true;
    };

    Sync<State> state_;

public:

    ProgressBar()
    {
    }

    ~ProgressBar()
    {
        stop();
    }

    void stop()
    {
        auto state(state_.lock());
        if (!state->active) return;
        state->active = true;
        std::string status = getStatus(*state);
        writeToStderr("\r\e[K");
        if (status != "")
            writeToStderr("[" + status + "]\n");
    }

    void log(Verbosity lvl, const FormatOrString & fs) override
    {
        auto state(state_.lock());
        log(*state, lvl, fs.s);
    }

    void log(State & state, Verbosity lvl, const std::string & s)
    {
        writeToStderr("\r\e[K" + s + ANSI_NORMAL "\n");
        update(state);
    }

    void startActivity(ActivityId act, Verbosity lvl, ActivityType type,
        const std::string & s, const Fields & fields, ActivityId parent) override
    {
        if (lvl <= verbosity && !s.empty())
            log(lvl, s + "...");

        auto state(state_.lock());

        state->activities.emplace_back(ActInfo());
        auto i = std::prev(state->activities.end());
        i->s = s;
        i->type = type;
        i->parent = parent;
        state->its.emplace(act, i);
        state->activitiesByType[type].its.emplace(act, i);

        if (type == actBuild) {
            auto name = storePathToName(getS(fields, 0));
            if (hasSuffix(name, ".drv"))
                name.resize(name.size() - 4);
            i->s = fmt("building " ANSI_BOLD "%s" ANSI_NORMAL, name);
        }

        if (type == actSubstitute) {
            auto name = storePathToName(getS(fields, 0));
            i->s = fmt("fetching " ANSI_BOLD "%s" ANSI_NORMAL " from %s", name, getS(fields, 1));
        }

        if ((type == actDownload && hasAncestor(*state, actCopyPath, parent))
            || (type == actCopyPath && hasAncestor(*state, actSubstitute, parent)))
            i->visible = false;

        update(*state);
    }

    /* Check whether an activity has an ancestore with the specified
       type. */
    bool hasAncestor(State & state, ActivityType type, ActivityId act)
    {
        while (act != 0) {
            auto i = state.its.find(act);
            if (i == state.its.end()) break;
            if (i->second->type == type) return true;
            act = i->second->parent;
        }
        return false;
    }

    void stopActivity(ActivityId act) override
    {
        auto state(state_.lock());

        auto i = state->its.find(act);
        if (i != state->its.end()) {
            auto & actByType = state->activitiesByType[i->second->type];
            actByType.done += i->second->done;
            actByType.failed += i->second->failed;

            for (auto & j : i->second->expectedByType)
                state->activitiesByType[j.first].expected -= j.second;

            actByType.its.erase(act);
            state->activities.erase(i->second);
            state->its.erase(i);
        }

        update(*state);
    }

    void result(ActivityId act, ResultType type, const std::vector<Field> & fields) override
    {
        auto state(state_.lock());

        if (type == resFileLinked) {
            state->filesLinked++;
            state->bytesLinked += getI(fields, 0);
            update(*state);
        }

        else if (type == resBuildLogLine) {
            auto lastLine = trim(getS(fields, 0));
            if (!lastLine.empty()) {
                auto i = state->its.find(act);
                assert(i != state->its.end());
                ActInfo info = *i->second;
                state->activities.erase(i->second);
                info.lastLine = lastLine;
                state->activities.emplace_back(info);
                i->second = std::prev(state->activities.end());
                update(*state);
            }
        }

        else if (type == resUntrustedPath) {
            state->untrustedPaths++;
            update(*state);
        }

        else if (type == resCorruptedPath) {
            state->corruptedPaths++;
            update(*state);
        }

        else if (type == resSetPhase) {
            auto i = state->its.find(act);
            assert(i != state->its.end());
            i->second->phase = getS(fields, 0);
            update(*state);
        }

        else if (type == resProgress) {
            auto i = state->its.find(act);
            assert(i != state->its.end());
            ActInfo & actInfo = *i->second;
            actInfo.done = getI(fields, 0);
            actInfo.expected = getI(fields, 1);
            actInfo.running = getI(fields, 2);
            actInfo.failed = getI(fields, 3);
            update(*state);
        }

        else if (type == resSetExpected) {
            auto i = state->its.find(act);
            assert(i != state->its.end());
            ActInfo & actInfo = *i->second;
            auto type = (ActivityType) getI(fields, 0);
            auto & j = actInfo.expectedByType[type];
            state->activitiesByType[type].expected -= j;
            j = getI(fields, 1);
            state->activitiesByType[type].expected += j;
            update(*state);
        }
    }

    void update()
    {
        auto state(state_.lock());
        update(*state);
    }

    void update(State & state)
    {
        if (!state.active) return;

        std::string line;

        std::string status = getStatus(state);
        if (!status.empty()) {
            line += '[';
            line += status;
            line += "]";
        }

        if (!state.activities.empty()) {
            if (!status.empty()) line += " ";
            auto i = state.activities.rbegin();

            while (i != state.activities.rend() && (!i->visible || (i->s.empty() && i->lastLine.empty())))
                ++i;

            if (i != state.activities.rend()) {
                line += i->s;
                if (!i->phase.empty()) {
                    line += " (";
                    line += i->phase;
                    line += ")";
                }
                if (!i->lastLine.empty()) {
                    if (!i->s.empty()) line += ": ";
                    line += i->lastLine;
                }
            }
        }

        writeToStderr("\r" + ansiTruncate(line, getWindowSize().second) + "\e[K");
    }

    std::string getStatus(State & state)
    {
        auto MiB = 1024.0 * 1024.0;

        std::string res;

        auto renderActivity = [&](ActivityType type, const std::string & itemFmt, const std::string & numberFmt = "%d", double unit = 1) {
            auto & act = state.activitiesByType[type];
            uint64_t done = act.done, expected = act.done, running = 0, failed = act.failed;
            for (auto & j : act.its) {
                done += j.second->done;
                expected += j.second->expected;
                running += j.second->running;
                failed += j.second->failed;
            }

            expected = std::max(expected, act.expected);

            std::string s;

            if (running || done || expected || failed) {
                if (running)
                    s = fmt(ANSI_BLUE + numberFmt + ANSI_NORMAL "/" ANSI_GREEN + numberFmt + ANSI_NORMAL "/" + numberFmt,
                        running / unit, done / unit, expected / unit);
                else if (expected != done)
                    s = fmt(ANSI_GREEN + numberFmt + ANSI_NORMAL "/" + numberFmt,
                        done / unit, expected / unit);
                else
                    s = fmt(done ? ANSI_GREEN + numberFmt + ANSI_NORMAL : numberFmt, done / unit);
                s = fmt(itemFmt, s);

                if (failed)
                    s += fmt(" (" ANSI_RED "%d failed" ANSI_NORMAL ")", failed / unit);
            }

            return s;
        };

        auto showActivity = [&](ActivityType type, const std::string & itemFmt, const std::string & numberFmt = "%d", double unit = 1) {
            auto s = renderActivity(type, itemFmt, numberFmt, unit);
            if (s.empty()) return;
            if (!res.empty()) res += ", ";
            res += s;
        };

        showActivity(actBuilds, "%s built");

        auto s1 = renderActivity(actCopyPaths, "%s copied");
        auto s2 = renderActivity(actCopyPath, "%s MiB", "%.1f", MiB);

        if (!s1.empty() || !s2.empty()) {
            if (!res.empty()) res += ", ";
            if (s1.empty()) res += "0 copied"; else res += s1;
            if (!s2.empty()) { res += " ("; res += s2; res += ')'; }
        }

        showActivity(actDownload, "%s MiB DL", "%.1f", MiB);

        {
            auto s = renderActivity(actOptimiseStore, "%s paths optimised");
            if (s != "") {
                s += fmt(", %.1f MiB / %d inodes freed", state.bytesLinked / MiB, state.filesLinked);
                if (!res.empty()) res += ", ";
                res += s;
            }
        }

        // FIXME: don't show "done" paths in green.
        showActivity(actVerifyPaths, "%s paths verified");

        if (state.corruptedPaths) {
            if (!res.empty()) res += ", ";
            res += fmt(ANSI_RED "%d corrupted" ANSI_NORMAL, state.corruptedPaths);
        }

        if (state.untrustedPaths) {
            if (!res.empty()) res += ", ";
            res += fmt(ANSI_RED "%d untrusted" ANSI_NORMAL, state.untrustedPaths);
        }

        return res;
    }
};

void startProgressBar()
{
    logger = new ProgressBar();
}

void stopProgressBar()
{
    auto progressBar = dynamic_cast<ProgressBar *>(logger);
    if (progressBar) progressBar->stop();

}

}