/*	$Id$ */
/*
 * Copyright (c) 2016 Kristaps Dzonsons <kristaps@bsd.lv>
 *
 * Permission to use, copy, modify, and distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 */
#include <stdarg.h>
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <time.h>
#include <unistd.h>

#include <kcgi.h>
#include <kcgijson.h>
#include "ksql.h"

#include "extern.h"

enum    stmt {
  STMT_SERIES,
  STMT_SERIES_AUTHORS,
  STMT_SERIE,
  STMT_SERIE_BOOKS,
  STMT_SERIE_AUTHORS,
  STMT__MAX
};

static const char *const stmts[STMT__MAX] = {
  /* STMT_SERIES */
  "SELECT series.id, series.name, count(book) FROM series \
    LEFT OUTER JOIN books_series_link ON books_series_link.series = series.id \
    GROUP BY series.id ORDER BY series.id LIMIT ? OFFSET ?",
  /* STMT_SERIES_AUTHORS */
  "SELECT DISTINCT authors.id, authors.name, books_series_link.series \
    FROM authors, books_authors_link, books_series_link \
    WHERE books_authors_link.book = books_series_link.book AND books_authors_link.author = authors.id \
    AND books_series_link.series IN ( SELECT id FROM series ORDER BY series.id LIMIT ? OFFSET ?)",
  /* STMT_SERIE */
  "SELECT series.id, series.name FROM series WHERE series.id = ?",
  /* STMT_SERIE_BOOKS */
  "SELECT books.id, title, series_index FROM books \
    LEFT OUTER JOIN books_series_link ON books.id = books_series_link.book \
    WHERE books_series_link.series = ?",
  /* STMT_SERIE_AUTHORS */
  "SELECT DISTINCT authors.id, authors.name \
    FROM authors, books_authors_link, books_series_link \
    WHERE books_authors_link.book = books_series_link.book AND books_authors_link.author = authors.id \
    AND books_series_link.series = ?",
};

struct seriesbook {
  SeriesFull *s;
  Book *b;
  struct seriesbook *p;
};

struct seriesauth {
  SeriesAdv *s;
  Author *a;
  struct seriesauth *p;
};

void
db_series_unfill(Series *p)
{
  if (NULL == p)
    return;
  free(p->name);
}

void
db_series_free(Series *p)
{
  if (NULL == p)
    return;
  db_series_unfill(p);
  free(p);
}

void
db_series_adv_free(SeriesAdv *p)
{
  if (NULL == p)
    return;
  db_series_unfill(&p->s);
  free(p);
}

static void
db_assign_series_authors(struct seriesauth *list)
{
  struct seriesauth *item = NULL;
  struct seriesauth *p = NULL;

  p = list;
  while (NULL != p) {
    if (NULL != p->s && NULL == p->s->a && p->s->asize > 0) {
      p->s->a = kcalloc(p->s->asize, sizeof(Author));
      p->s->asize = 0; // use as counter for insert
    }
    p->s->a[p->s->asize] = p->a;
    p->s->asize++;
    item = p;
    p = p->p;
    free(item);
  }
}

static struct seriesauth *
db_load_series_authors(SeriesAdv **series, int count, struct ksqlstmt *stmt)
{
  struct seriesauth *item = NULL;
  struct seriesauth *p = NULL;
  int64_t sid = -1;
  int i = 0;

  while (KSQL_ROW == ksql_stmt_step(stmt)) {
    item = kcalloc(1, sizeof(struct seriesauth));
    item->a = kcalloc(1, sizeof(Author));
    item->a->id = ksql_stmt_int(stmt, 0);
    item->a->name = kstrdup(ksql_stmt_str(stmt, 1));
    sid = ksql_stmt_int(stmt, 2);
    for (i = 0; i < count && NULL == item->s; i++) {
      if (series[i]->s.id == sid) {
        item->s = series[i];
        item->s->asize++;
      }
    }
    item->p = p;
    p = item;
  }
  return p;
}

static struct seriesbook*
db_load_series_books(struct kreq *r, SeriesFull *series, int64_t id)
{
  struct ksqlstmt *stmt;
  struct seriesbook *p = NULL;
  struct seriesbook *item = NULL;

  ksql_stmt_alloc(r->arg, &stmt, 
            stmts[STMT_SERIE_BOOKS], 
            STMT_SERIE_BOOKS);
  ksql_bind_int(stmt, 0, id);
  while (KSQL_ROW == ksql_stmt_step(stmt)) {
    item = kcalloc(1,sizeof(struct seriesbook));
    Book *b = kcalloc(1, sizeof(Book));
    b->id = ksql_stmt_int(stmt, 0);
    b->title = kstrdup(ksql_stmt_str(stmt, 1));
    b->s_idx = ksql_stmt_int(stmt, 2);
    b->s = series->s.s;
    item->b = b;
    item->s = series;
    series->s.books++;
    
    item->p = p;
    p = item;
  }
  ksql_stmt_free(stmt);

  return p;
}

static void
db_assign_series_books(struct seriesbook *list)
{
  struct seriesbook *p = NULL;
  struct seriesbook *item = NULL;

  p = list;
  while (NULL != p) {
    if (NULL != p->s && NULL == p->s->b && p->s->s.books > 0) {
      p->s->b = kcalloc(p->s->s.books, sizeof(Book));
      p->s->s.books = 0; // use as counter for insert
    }
    p->s->b[p->s->s.books] = p->b;
    p->s->s.books++;
    item = p;
    p = p->p;
    free(item);
  }
}

SeriesFull *
db_serie_load(struct kreq *r, int64_t id)
{
  struct ksqlstmt *stmt;
  SeriesFull  *series;
  struct seriesauth *p = NULL;
  struct seriesauth *item = NULL;
  struct seriesbook *list = NULL;

  ksql_stmt_alloc(r->arg, &stmt, 
            stmts[STMT_SERIE], 
            STMT_SERIE);
  ksql_bind_int(stmt, 0, id);
  if (KSQL_ROW != ksql_stmt_step(stmt)) {
    ksql_stmt_free(stmt);
    return(NULL);
  }
  series = kcalloc(1, sizeof(SeriesFull));
  series->s.s.id = ksql_stmt_int(stmt, 0);
  series->s.s.name = kstrdup(ksql_stmt_str(stmt, 1));
  series->s.books = 0;
  series->s.asize = 0;
  ksql_stmt_free(stmt);

  list = db_load_series_books(r, series, id);
  db_assign_series_books(list);

  ksql_stmt_alloc(r->arg, &stmt, 
            stmts[STMT_SERIE_AUTHORS], 
            STMT_SERIE_AUTHORS);
  ksql_bind_int(stmt, 0, id);
  while (KSQL_ROW == ksql_stmt_step(stmt)) {
    item = kcalloc(1, sizeof(struct seriesauth));
    item->a = kcalloc(1, sizeof(Author));
    item->a->id = ksql_stmt_int(stmt, 0);
    item->a->name = kstrdup(ksql_stmt_str(stmt, 1));
    item->s = &series->s;
    item->s->asize++;

    item->p = p;
    p = item;
  }
  ksql_stmt_free(stmt);

  db_assign_series_authors(p);

  return series;
}

int
db_series_load(struct kreq *r, SeriesAdv **series, int limit, int offset)
{
  if (limit < 0 || offset < 0) {
    return 0;
  }
  struct ksqlstmt *stmt;
  int count = 0;
  struct seriesauth *p = NULL;

  ksql_stmt_alloc(r->arg, &stmt, 
            stmts[STMT_SERIES], 
            STMT_SERIES);
  ksql_bind_int(stmt, 0, limit);
  ksql_bind_int(stmt, 1, offset);
  while (KSQL_ROW == ksql_stmt_step(stmt)) {
    series[count] = kcalloc(1, sizeof(SeriesAdv));
    series[count]->s.id = ksql_stmt_int(stmt, 0);
    series[count]->s.name = kstrdup(ksql_stmt_str(stmt, 1));
    series[count]->books = ksql_stmt_int(stmt, 2);
    series[count]->asize = 0;
    count++;
  }
  ksql_stmt_free(stmt);

  ksql_stmt_alloc(r->arg, &stmt, 
            stmts[STMT_SERIES_AUTHORS], 
            STMT_SERIES_AUTHORS);
  ksql_bind_int(stmt, 0, limit);
  ksql_bind_int(stmt, 1, offset);
  p = db_load_series_authors(series, count, stmt);
  ksql_stmt_free(stmt);

  db_assign_series_authors(p);

  return count;
}