// tests for pasted text: tests/test_text.cpp
//
// The character map is the part worth being pedantic about: every one of the 95
// printable ASCII characters has to map to a real keystroke, because a paste that
// silently loses or changes one character is worse than a paste that refuses. So
// the whole range is walked, not sampled.
#include <cstdio>
#include <cstring>
#include <string>
#include <vector>

#include "keystate.h"
#include "proto.h"
#include "test.h"
#include "text.h"

using kr::KeyboardReport;
using kr::KeyboardState;
using kr::text::Result;
using kr::text::Stroke;
using kr::text::Typewriter;

namespace {

int countHeld(const KeyboardReport &r) {
  int n = 0;
  for (size_t i = 0; i < kr::kReportSlots; i++) {
    if (r.keys[i] != kr::kUsageNone) n++;
  }
  return n;
}

}  // namespace

int main() {
  CASE("every printable ASCII character maps to a keystroke");
  {
    for (int ch = 0x20; ch <= 0x7E; ch++) {
      const Stroke s = kr::text::strokeFor(static_cast<uint8_t>(ch));
      CHECK(s.typable);
      CHECK(s.usage != kr::kUsageNone);          // typable implies a real usage id
    }
  }

  CASE("shifted glyphs ask for LShift, unshifted ones do not");
  {
    // Letters: position, plus Shift for the uppercase -- never a different key.
    const Stroke a = kr::text::strokeFor('a'), A = kr::text::strokeFor('A');
    CHECK(a.typable && A.typable);
    CHECK_EQ(a.usage, 0x04);
    CHECK_EQ(A.usage, 0x04);                     // same physical key
    CHECK_EQ(a.mods, 0);
    CHECK_EQ(A.mods, kr::kModLshift);
    CHECK_EQ(kr::text::strokeFor('z').usage, 0x1D);
    CHECK_EQ(kr::text::strokeFor('Z').usage, 0x1D);
    CHECK_EQ(kr::text::strokeFor('M').usage, 0x10);

    // Digits: 1..9 run 0x1E..0x26 and 0 is the one that breaks the arithmetic.
    CHECK_EQ(kr::text::strokeFor('1').usage, 0x1E);
    CHECK_EQ(kr::text::strokeFor('9').usage, 0x26);
    CHECK_EQ(kr::text::strokeFor('0').usage, 0x27);
    CHECK_EQ(kr::text::strokeFor('0').mods, 0);

    // The shifted number row, which is where a shifted-vs-unshifted slip shows up.
    const int shiftPairs[][2] = {
      {'!', 0x1E}, {'@', 0x1F}, {'#', 0x20}, {'$', 0x21}, {'%', 0x22},
      {'^', 0x23}, {'&', 0x24}, {'*', 0x25}, {'(', 0x26}, {')', 0x27},
      {'_', 0x2D}, {'+', 0x2E}, {'{', 0x2F}, {'}', 0x30}, {'|', 0x31},
      {':', 0x33}, {'"', 0x34}, {'~', 0x35}, {'<', 0x36}, {'>', 0x37},
      {'?', 0x38},
    };
    for (const auto &p : shiftPairs) {
      const Stroke s = kr::text::strokeFor(static_cast<uint8_t>(p[0]));
      CHECK(s.typable);
      CHECK_EQ(s.usage, p[1]);
      CHECK_EQ(s.mods, kr::kModLshift);
    }

    // And their unshifted partners on the same keys.
    CHECK_EQ(kr::text::strokeFor('-').usage, 0x2D);
    CHECK_EQ(kr::text::strokeFor('-').mods, 0);
    CHECK_EQ(kr::text::strokeFor('=').usage, 0x2E);
    CHECK_EQ(kr::text::strokeFor('[').usage, 0x2F);
    CHECK_EQ(kr::text::strokeFor(']').usage, 0x30);
    CHECK_EQ(kr::text::strokeFor('\\').usage, 0x31);
    CHECK_EQ(kr::text::strokeFor(';').usage, 0x33);
    CHECK_EQ(kr::text::strokeFor('\'').usage, 0x34);
    CHECK_EQ(kr::text::strokeFor('`').usage, 0x35);
    CHECK_EQ(kr::text::strokeFor(',').usage, 0x36);
    CHECK_EQ(kr::text::strokeFor('.').usage, 0x37);
    CHECK_EQ(kr::text::strokeFor('/').usage, 0x38);
  }

  CASE("whitespace");
  {
    CHECK_EQ(kr::text::strokeFor(' ').usage, kr::kUsageSpace);
    CHECK_EQ(kr::text::strokeFor('\t').usage, kr::kUsageTab);
    CHECK_EQ(kr::text::strokeFor('\n').usage, kr::kUsageEnter);
    // \r types Enter. Normalising CRLF to LF is the controller's job: doing it here
    // would need a look-ahead, and a chunk boundary can split the pair.
    CHECK_EQ(kr::text::strokeFor('\r').usage, kr::kUsageEnter);
  }

  CASE("characters this map cannot express are refused, not guessed at");
  {
    const int refused[] = {0x00, 0x01, 0x07, 0x08, 0x0B, 0x0C, 0x1B, 0x1F, 0x7F,
                           0x80, 0xA0, 0xC3, 0xE9, 0xFF};   // e.g. UTF-8 'é'
    for (int ch : refused) {
      const Stroke s = kr::text::strokeFor(static_cast<uint8_t>(ch));
      CHECK(!s.typable);
      CHECK_EQ(s.usage, 0);
      CHECK_EQ(s.mods, 0);
    }
  }

  CASE("feed: all of a frame or none of it");
  {
    Typewriter t;
    const uint8_t ok[] = {'h', 'i'};
    CHECK(kr::text::strokeFor('h').typable);
    CHECK(t.feed(ok, 2).result == Result::Ok);
    CHECK_EQ(t.pending(), 2);

    const uint8_t mixed[] = {'o', '!', 0xC3, 'x'};
    const auto bad = t.feed(mixed, 4);
    CHECK(bad.result == Result::Untypeable);
    CHECK_EQ(bad.index, 2);                      // offset within THIS frame
    CHECK_EQ(bad.byte, 0xC3);
    CHECK_EQ(t.pending(), 2);                    // nothing partial was appended

    // The cap is on characters still to type, and a full buffer is reported as such
    // rather than truncating a paste.
    Typewriter big;
    uint8_t run[kr::kTextJobCap];
    memset(run, 'a', sizeof(run));
    CHECK(big.feed(run, kr::kTextJobCap).result == Result::Ok);
    CHECK(big.feed(run, 1).result == Result::Full);
    CHECK_EQ(big.pending(), kr::kTextJobCap);

    CHECK(Typewriter().feed(nullptr, 0).result == Result::Ok);
  }

  CASE("pace: 0 means the board's default, and a fast pace still separates edges");
  {
    Typewriter t;
    const uint8_t one[] = {'q'};
    t.feed(one, 1);
    t.start(1000, 0);
    CHECK_EQ(t.periodMs(), kr::kTextPeriodMsDefault);
    CHECK(t.holdMs() >= 1);
    CHECK(t.holdMs() <= kr::kTextHoldMaxMs);
    CHECK_EQ(t.holdMs() + t.gapMs(), t.periodMs());   // one press and one release per char

    t.cancel();
    t.feed(one, 1);
    t.start(0, 9999);                            // absurdly slow is clamped, not obeyed
    CHECK_EQ(t.periodMs(), kr::kTextPeriodMaxMs);
    CHECK_EQ(t.holdMs(), kr::kTextHoldMaxMs);

    t.cancel();
    t.feed(one, 1);
    t.start(0, 1);                               // as fast as it will go
    CHECK_EQ(t.holdMs(), 1);
    CHECK_EQ(t.gapMs(), 0);
  }

  CASE("step: the whole report sequence for two characters");
  {
    Typewriter t;
    const uint8_t txt[] = {'h', 'i'};
    t.feed(txt, 2);
    t.start(1000, 10);                           // hold 5, gap 5
    CHECK_EQ(t.holdMs(), 5);
    CHECK_EQ(t.gapMs(), 5);

    KeyboardState baseline;
    KeyboardReport r;
    bool pressed = false;

    CHECK(!t.step(999, baseline, r, pressed));    // not due yet
    CHECK(t.step(1000, baseline, r, pressed));    // press 'h'
    CHECK(pressed);
    CHECK_EQ(r.modifiers, 0);
    CHECK_EQ(countHeld(r), 1);
    CHECK_EQ(r.keys[0], kr::text::strokeFor('h').usage);

    CHECK(!t.step(1004, baseline, r, pressed));   // still holding
    CHECK(t.step(1005, baseline, r, pressed));    // release
    CHECK(!pressed);
    CHECK_EQ(countHeld(r), 0);

    CHECK(t.step(1010, baseline, r, pressed));    // press 'i'
    CHECK(pressed);
    CHECK_EQ(r.keys[0], kr::text::strokeFor('i').usage);
    CHECK(t.step(1015, baseline, r, pressed));    // release, and the run is over
    CHECK(!t.active());
    CHECK_EQ(t.pending(), 0);
    CHECK(!t.step(2000, baseline, r, pressed));   // and nothing is left to emit
  }

  CASE("a paste is typed on top of what the operator holds, and back to it");
  {
    Typewriter t;
    const uint8_t txt[] = {'A'};                 // uppercase: this one needs Shift
    t.feed(txt, 1);
    t.start(0, 20);

    // The operator is holding Ctrl. A pasted 'A' is therefore Ctrl+Shift+a.
    KeyboardState baseline;
    const uint8_t held[] = {kr::text::strokeFor('s').usage};
    baseline.apply(kr::kModLctrl, held, 1);

    KeyboardReport r;
    bool pressed = false;
    CHECK(t.step(0, baseline, r, pressed));
    CHECK_EQ(r.modifiers, kr::kModLctrl | kr::kModLshift);
    CHECK_EQ(countHeld(r), 2);
    CHECK(baseline.isDown(kr::text::strokeFor('s').usage));

    CHECK(t.step(10, baseline, r, pressed));      // release returns to the baseline
    CHECK_EQ(r.modifiers, kr::kModLctrl);         // Ctrl still down
    CHECK_EQ(countHeld(r), 1);
    CHECK_EQ(r.keys[0], kr::text::strokeFor('s').usage);   // not released by the paste
  }

  CASE("more than six keys together is reported as a real keyboard reports it");
  {
    Typewriter t;
    const uint8_t txt[] = {'x'};
    t.feed(txt, 1);
    t.start(0, 20);

    KeyboardState six;
    const uint8_t keys6[] = {0x04, 0x05, 0x06, 0x07, 0x08, 0x09};
    six.apply(0, keys6, 6);
    KeyboardReport r;
    bool pressed = false;
    CHECK(t.step(0, six, r, pressed));            // a seventh key is impossible:
    for (size_t i = 0; i < kr::kReportSlots; i++) CHECK_EQ(r.keys[i], kr::kUsageErrorRollover);

    KeyboardState rolled;
    const uint8_t keys7[] = {0x04, 0x05, 0x06, 0x07, 0x08, 0x09, 0x0A};
    rolled.apply(0, keys7, 7);
    CHECK(rolled.rollover());
    Typewriter t2;
    t2.feed(txt, 1);
    t2.start(0, 20);
    CHECK(t2.step(0, rolled, r, pressed));
    CHECK_EQ(r.keys[0], kr::kUsageErrorRollover);  // rollover propagates, never hides
  }

  CASE("cancel drops the rest of the run");
  {
    Typewriter t;
    const uint8_t txt[] = {'o', 'n', 'e', ' ', 't', 'w', 'o'};
    t.feed(txt, sizeof(txt));
    t.start(0, 10);
    CHECK(t.active());

    KeyboardState baseline;
    KeyboardReport r;
    bool pressed = false;
    CHECK(t.step(0, baseline, r, pressed));       // one character pressed
    t.cancel();                                   // the panic path
    CHECK(!t.active());
    CHECK_EQ(t.pending(), 0);
    CHECK(!t.step(1000, baseline, r, pressed));   // nothing continues afterwards
    CHECK_EQ(t.feed(txt, sizeof(txt)).result, Result::Ok);
    CHECK_EQ(t.pending(), sizeof(txt));               // and it is reusable
  }

  CASE("a run already in progress keeps the pace it started with");
  {
    Typewriter t;
    const uint8_t txt[] = {'a'};
    t.feed(txt, 1);
    t.start(0, 10);
    CHECK_EQ(t.periodMs(), 10);
    t.feed(txt, 1);
    t.start(0, 200);                              // a later frame must not reprieve
    CHECK_EQ(t.periodMs(), 10);                   // or race the text already visible
    t.cancel();
    t.feed(txt, 1);
    t.start(0, 200);
    CHECK_EQ(t.periodMs(), 200);                  // a fresh run does take the new pace
  }

  CASE("text renders to the wire format and parses back");
  {
    char buf[512];
    const uint8_t txt[] = {'h', 'i'};
    const size_t n = kr::proto::formatText(buf, sizeof(buf), 0, txt, 2);
    CHECK_EQ(n, 8u);                             // "P=0:6869"
    CHECK_STR(buf, "P=0:6869");

    kr::proto::Message m;
    CHECK(kr::proto::parse(buf, strlen(buf), m) == kr::proto::Cmd::Text);
    CHECK_EQ(m.periodMs, 0);
    CHECK_EQ(m.nPayload, 2);
    CHECK_EQ(m.payload[0], 'h');
    CHECK_EQ(m.payload[1], 'i');

    // The pace travels too, in decimal, and the whole frame is still ASCII.
    kr::proto::formatText(buf, sizeof(buf), 250, txt, 2);
    CHECK_STR(buf, "P=250:6869");
    CHECK(kr::proto::parse(buf, strlen(buf), m) == kr::proto::Cmd::Text);
    CHECK_EQ(m.periodMs, 250);

    // The largest legal frame must fit in one WebSocket message: 256 bytes, or the
    // board rejects the frame before the parser ever sees it.
    uint8_t max[kr::kTextFrameMax];
    memset(max, 'a', sizeof(max));
    const size_t mlen = kr::proto::formatText(buf, sizeof(buf), kr::kTextPeriodMaxMs,
                                              max, kr::kTextFrameMax);
    CHECK(mlen > 0);
    CHECK(mlen <= kr::kWsMessageCap);
    CHECK(kr::proto::parse(buf, mlen, m) == kr::proto::Cmd::Text);
    CHECK_EQ(m.nPayload, kr::kTextFrameMax);

    // A buffer that cannot hold the whole frame gets nothing, not a truncated paste.
    char small[8] = {0};
    CHECK_EQ(kr::proto::formatText(small, sizeof(small), 0, max, 20), 0u);
    CHECK_STR(small, "");
    CHECK_EQ(kr::proto::formatText(buf, sizeof(buf), 0, max, 0), 0u);   // empty is not a paste
    CHECK_EQ(kr::proto::formatText(buf, sizeof(buf), kr::kTextPeriodMaxMs + 1, txt, 2), 0u);
  }

  CASE("a frame the controller page sends becomes the reports the target sees");
  {
    // The browser builds "P=<ms>:<hex>"; the board parses it, expands it and emits
    // press/release pairs. This is the whole path in one place, with no browser and no
    // USB in it -- which is exactly why it can be asserted here rather than guessed at.
    const char *text = "Hi there";
    std::string frame = "P=12:";
    for (const char *p = text; *p; p++) {
      char hex[3];
      snprintf(hex, sizeof(hex), "%02x", (unsigned char)*p);
      frame += hex;
    }

    kr::proto::Message m;
    CHECK(kr::proto::parse(frame.c_str(), frame.size(), m) == kr::proto::Cmd::Text);
    CHECK_EQ(m.nPayload, strlen(text));
    CHECK_EQ(m.periodMs, 12);

    Typewriter t;
    CHECK(t.feed(m.payload, m.nPayload).result == Result::Ok);
    t.start(0, m.periodMs);

    KeyboardState none;                       // nothing held by the operator
    std::vector<KeyboardReport> out;
    uint32_t clockMs = 0;
    // Ten seconds of loop passes at 1 ms: long enough to type it all out.
    for (int tick = 0; tick < 10000; tick++, clockMs += 1) {
      KeyboardReport r;
      bool pressed = false;
      if (!t.step(clockMs, none, r, pressed)) continue;
      out.push_back(r);
    }

    const size_t len = strlen(text);
    CHECK_EQ(out.size(), len * 2);            // one press and one release per character
    CHECK(!t.active());                       // and it finished on its own
    for (size_t i = 0; i < len; i++) {
      const Stroke want = kr::text::strokeFor((uint8_t)text[i]);
      const KeyboardReport &press = out[i * 2];
      const KeyboardReport &release = out[i * 2 + 1];
      CHECK_EQ(press.modifiers, want.mods);
      CHECK_EQ(press.keys[0], want.usage);
      CHECK_EQ(countHeld(press), 1);
      CHECK_EQ(release.modifiers, 0);         // nothing left down between characters
      CHECK_EQ(countHeld(release), 0);
    }
    // 'H' is the shifted glyph and 'i' is not: the two reports differ in Shift and
    // nothing else. Usages are positions, so H is 0x0B and i is 0x0C.
    CHECK_EQ(out[0].modifiers, kr::kModLshift);
    CHECK_EQ(out[0].keys[0], 0x0b);
    CHECK_EQ(out[2].modifiers, 0);
    CHECK_EQ(out[2].keys[0], 0x0c);
    // The space in "Hi there" is index 2, and a key -- not an absence of one.
    CHECK_EQ(out[4].keys[0], kr::kUsageSpace);
    CHECK_EQ(out[6].keys[0], 0x17);            // 't'
  }

  return report("text");
}