#include "printbuffer.hpp"
#include <algorithm>
#include <sstream>

PrintBuffer::PrintBuffer(util::WorldType wt) {
    world_type_ = wt;
    clear();
}

static int first_line_len(const char *text, int len) {
    for (int i = 0; i < len; i++) {
        if (text[i] == '\n') return i;
    }
    return len;
}

void PrintBuffer::add_line(const char *text, int len) {
    lines_.emplace_back(text, len);
    if ((world_type_ == util::WORLD_TYPE_MASTER)||(world_type_ == util::WORLD_TYPE_STANDALONE)) {
        first_unchecked_ = first_line_ + int(lines_.size());
    }
}

void PrintBuffer::add_string(const char *text, int len) {
    while (true) {
        int fll = first_line_len(text, len);
        if (fll == len) {
            if (len > 0) {
                add_line(text, len);
            }
            return;
        } else {
            add_line(text, fll);
            text += (fll + 1);
            len -= (fll + 1);
        }
    }
}

void PrintBuffer::add_string(const std::string &s) {
    add_string(s.c_str(), s.size());
}

void PrintBuffer::discard_upto(int n) {
    while ((!lines_.empty()) && (first_line_ < n)) {
        lines_.pop_front();
        first_line_ += 1;
    }
    if (first_unchecked_ < first_line_) {
        first_unchecked_ = first_line_;
    }
}

void PrintBuffer::clear() {
    first_line_ = 0;
    first_unchecked_ = 0;
    lines_.clear();
}

std::string PrintBuffer::debug_string() const {
    std::ostringstream oss;
    oss << first_line_ << "," << first_unchecked_ << ":";
    for (int i = 0; i < int(lines_.size()); i++) {
        oss << lines_[i] << ";";
    }
    return oss.str();
}


void PrintBuffer::diff(const PrintBuffer &auth, StreamBuffer *sb) const {
    // Currently, the implementation is simple.  The synchronous model discards
    // all prediction lines from its buffer, then the server retransmits all
    // those lines.  So this barely counts as difference transmission - it's
    // just transmission, regardless of what was in the synchronous model.  I
    // think that's okay for the text console.
    // Ask the client to discard anything that precedes auth_first.
    sb->write_int32(auth.first_line_);
    sb->write_int32(auth.last_line());
    for (int i = first_unchecked_; i < auth.last_line(); i++) {
        std::string line;
        if (i >= auth.first_line_) line = auth.nth(i);
        sb->write_string(line);
    }
}

void PrintBuffer::patch(StreamBuffer *sb) {
    int auth_first = sb->read_int32();
    int auth_last = sb->read_int32();
    lines_.resize(first_unchecked_ - first_line_);
    for (int i = first_unchecked_; i < auth_last; i++) {
        lines_.emplace_back(sb->read_string());
    }
    first_unchecked_ = first_line_ + lines_.size();
    discard_upto(auth_first);
    if (first_line_ < auth_first) {
        first_line_ = auth_first;
    }
}

LuaDefine(unittests_printbuffer, "c") {
    PrintBuffer pbm(util::WORLD_TYPE_MASTER);
    PrintBuffer pbs(util::WORLD_TYPE_S_SYNC);
    StreamBuffer sb;

    LuaAssertStrEq(L, pbm.debug_string(), "0,0:");
    pbm.add_string("foo\nbar\nbaz\n");
    LuaAssertStrEq(L, pbm.debug_string(), "0,3:foo;bar;baz;");
    pbm.add_string("a\nb\nc");
    LuaAssertStrEq(L, pbm.debug_string(), "0,6:foo;bar;baz;a;b;c;");
    pbm.discard_upto(2);
    LuaAssertStrEq(L, pbm.debug_string(), "2,6:baz;a;b;c;");
    pbm.discard_upto(8);
    LuaAssertStrEq(L, pbm.debug_string(), "6,6:");

    LuaAssertStrEq(L, pbs.debug_string(), "0,0:");
    pbs.add_string("foo\nbar\nbaz\n");
    LuaAssertStrEq(L, pbs.debug_string(), "0,0:foo;bar;baz;");
    pbs.add_string("a\nb\nc");
    LuaAssertStrEq(L, pbs.debug_string(), "0,0:foo;bar;baz;a;b;c;");
    pbs.discard_upto(2);
    LuaAssertStrEq(L, pbs.debug_string(), "2,2:baz;a;b;c;");
    pbs.discard_upto(8);
    LuaAssertStrEq(L, pbs.debug_string(), "6,6:");

    pbm.clear();
    pbs.clear();
    sb.clear();
    pbm.add_string("foo\nbar\n");
    pbs.diff(pbm, &sb);
    pbs.patch(&sb);
    LuaAssertStrEq(L, pbs.debug_string(), "0,2:foo;bar;");
    pbm.clear();
    pbm.add_string("foo\nyow\nding\ndong\n");
    pbs.diff(pbm, &sb);
    pbs.patch(&sb);
    LuaAssertStrEq(L, pbs.debug_string(), "0,4:foo;bar;ding;dong;");
    pbs.discard_upto(2);
    LuaAssertStrEq(L, pbs.debug_string(), "2,4:ding;dong;");
    pbs.diff(pbm, &sb);
    pbs.patch(&sb);
    LuaAssertStrEq(L, pbs.debug_string(), "2,4:ding;dong;");
    pbs.add_string("boy\nhowdy\n");
    LuaAssertStrEq(L, pbs.debug_string(), "2,4:ding;dong;boy;howdy;");
    pbs.diff(pbm, &sb);
    pbs.patch(&sb);
    LuaAssertStrEq(L, pbs.debug_string(), "2,4:ding;dong;");
    pbs.add_string("boy\nhowdy\nyeah\nbaby\nget\ndown\n");
    LuaAssertStrEq(L, pbs.debug_string(), "2,4:ding;dong;boy;howdy;yeah;baby;get;down;");
    pbs.discard_upto(5);
    LuaAssertStrEq(L, pbs.debug_string(), "5,5:howdy;yeah;baby;get;down;");
    pbs.diff(pbm, &sb);
    pbs.patch(&sb);
    LuaAssertStrEq(L, pbs.debug_string(), "5,5:");
    
    return 0;
}