#include <helianthus.h></helianthus.h>

#include <string.h></string.h>

#include <stdio.h></stdio.h>

#define MAXREC     1000

#define ANSWERS       4

#define MAXQUESTS    10

typedef struct {

  char text[128];

} Date;

typedef struct {

  char text[1024];

} Text;

typedef struct {

  char text[128];

} Part;

typedef struct {

  Date date;

  Text text;

  Part part;

} BaseRecord;

typedef struct {

  Date *date;

  Text *text;

  Part *part;

  int error;

} Record;

typedef struct {

  Date *date;

  int error;

} Answer;

BaseRecord recordsSrc[MAXREC];

Record records[MAXREC];

Part *parts[MAXREC];

Date *dates[MAXREC];

int partCount;

int dateCount;

int recCount;

int mode;

int errorCount;

int curError;

int curRec;

double questionFade;

Answer answers[ANSWERS];

void load(const char *filename) {

  recCount = 0;

  partCount = 0;

  dateCount = 0;

  memset(recordsSrc, 0, sizeof(recordsSrc));

  memset(records, 0, sizeof(records));

  memset(parts, 0, sizeof(parts));

  memset(dates, 0, sizeof(dates));

  FILE *f = fopen(filename, "r");

  if (!f) {

    printf("cannot open file for read: %s\n", filename);

    return;

  }

  int mode = 0;

  BaseRecord *rs = recordsSrc;

  char *p = rs->date.text;

  char *e = p + sizeof(rs->date.text);

  while(1) {

    int c = fgetc(f);

    if (c <= 0 || c >= 256) break;

    if (c == '\t') {

      if (mode == 0) {

        mode = 1; p = rs->text.text; e = p + sizeof(rs->text.text);

      } else

      if (mode == 1) {

        mode = 2; p = rs->part.text; e = p + sizeof(rs->part.text);

      } else

      if (mode == 2) {

        mode = 3;

      }

    } else

    if (c == '\n') {

        if (rs->date.text[0] || rs->text.text[0] || rs->part.text[0]) {

          ++recCount; ++rs;

          if (recCount >= MAXREC) break;

        }

        mode = 0; p = rs->date.text; e = p + sizeof(rs->date.text);

    } else

    if (c != '\r' && p+1 < e) {

      *p++ = c;

    }

  }

  fclose(f);

  if (recCount < MAXREC)

    if (rs->date.text[0] || rs->text.text[0] || rs->part.text[0])

      ++recCount;

  for(int i = 0; i < recCount; ++i) {

    Record *r = &records[i];

    BaseRecord *rs = &recordsSrc[i];

    for(int j = 0; j <= i; ++j) {

      BaseRecord *rrs = &recordsSrc[j];

      if (!r->date && !strcmp(rs->date.text, rrs->date.text)) r->date = &rrs->date;

      if (!r->text && !strcmp(rs->text.text, rrs->text.text)) r->text = &rrs->text;

      if (!r->part && !strcmp(rs->part.text, rrs->part.text)) r->part = &rrs->part;

    }

    if (r->part == &rs->part)

      parts[partCount++] = r->part;

    if (r->date == &rs->date)

      dates[dateCount++] = r->date;

  }

  for(int i = 0; i < 2*recCount; ++i) {

    int a = randomNumber(0, recCount - 1);

    int b = randomNumber(0, recCount - 1);

    if (a == b) continue;

    Record r;

    memcpy(&r, &records[a], sizeof(r));

    memcpy(&records[a], &records[b], sizeof(r));

    memcpy(&records[b], &r, sizeof(r));

  }

  if (recCount > MAXQUESTS)

    recCount = MAXQUESTS;

}

void nextQuestion() {

  if (mode != 2) return;

  if (!curError) ++curRec;

  if (curRec >= recCount)

    { mode = 3; return; }

  curError = 0;

  mode = 1;

  int q = randomNumber(curRec, recCount-1);

  if (q != curRec) {

    Record r;

    memcpy(&r, &records[curRec], sizeof(r));

    memcpy(&records[curRec], &records[q], sizeof(r));

    memcpy(&records[q], &r, sizeof(r));

  }

  for(int i = 0; i < ANSWERS; ++i) {

    for(int j = 0; j < 100; ++j) {

      answers[i].date = dates[randomNumber(0, dateCount-1)];

      if (answers[i].date != records[curRec].date) break;

    }

    answers[i].error = 0;

  }

  answers[randomNumber(0, ANSWERS-1)].date = records[curRec].date;

}

void startTest() {

  mode = 2;

  curRec = -1;

  curError = 0;

  errorCount = 0;

  for(int i = 0; i < recCount; ++i)

    records[i].error = 0;

  nextQuestion();

}

void giveAnswer(int i) {

  if (mode != 1) return;

  if (answers[i].date == records[curRec].date) {

    mode = 2;

  } else {

    curError = 1;

    if (!records[curRec].error) {

      records[curRec].error = 1;

      ++errorCount;

    }

    for(int j = 0; j < ANSWERS; ++j)

      if (answers[j].date != records[curRec].date)

        answers[j].error = 1;

  }

}

void init() {

  load("data/history/ancient-dates.txt");

  startTest();

}

void draw() {

  saveState();

  double w = windowGetWidth();

  double h = windowGetHeight();

  translate(w/2, h/2);

  double my = mouseTransformedY();

  saveState();

  if (mode == 1 || mode == 2) {

    noFill();

    strokeWidth(2);

    stroke(COLOR_BLACK);

    textAlign(HALIGN_CENTER, VALIGN_CENTER);

    textf(0, -200, "%d / %d", curRec+1, recCount);

    textSize(32);

    text(0, -100, records[curRec].text->text);

    textSize(24);

    textAlign(HALIGN_LEFT, VALIGN_TOP);

    line(-150, -65, 150, -65);

    double y = -40, dy = 40;

    int hover = -1;

    for(int i = 0; i < ANSWERS; ++i) {

      if (answers[i].error) {

        stroke(COLOR_RED);

      } else

      if (mode == 2) {

        if (answers[i].date == records[curRec].date) {

          circle(-130, y+i*dy+20, 10);

          stroke(COLOR_BLUE);

          fill(COLOR_BLUE);

          circle(-130, y+i*dy+20, 5);

          noFill();

        }

      } else {

        circle(-130, y+i*dy+20, 10);

        if (my > y+i*dy && my < y+(i+1)*dy) {

          hover = i;

          stroke(COLOR_BLUE);

          fill(COLOR_BLUE);

          circle(-130, y+i*dy+20, 5);

          noFill();

        }

      }

      text(-100, y + i*dy, answers[i].date->text);

      stroke(COLOR_BLACK);

    }

    if (mode == 1) {

      questionFade += windowGetFrameTime();

      if (questionFade > 1) questionFade = 1;

      if (hover >= 0 && mouseWentDown("left"))

        giveAnswer(hover);

    } else {

      questionFade -= windowGetFrameTime();

      if (questionFade < 0) {

        questionFade = 0;

        nextQuestion();

      }

    }

  } else

  if (mode == 3) {

    textSize(64);

    textAlign(HALIGN_CENTER, HALIGN_CENTER);

    textf(0, 0, "%d / %d", recCount - errorCount, recCount);

    questionFade += windowGetFrameTime();

    if (questionFade > 1) questionFade = 1;

  }

  restoreState();

  noStroke();

  fill(colorByRGBA(1, 1, 1, 1-questionFade));

  rect(-w/2, -h/2, w, h);

  restoreState();

}

int main() {

  windowSetSize(800, 600);

  windowSetResizable(TRUE);

  windowSetVariableFrameRate();

  windowSetInit(&init);

  windowSetDraw(&draw);

  windowRun();

  return 0;

}