// Copyright (C) 2004-2024 Artifex Software, Inc.

//

// This file is part of MuPDF.

//

// MuPDF is free software: you can redistribute it and/or modify it under the

// terms of the GNU Affero General Public License as published by the Free

// Software Foundation, either version 3 of the License, or (at your option)

// any later version.

//

// MuPDF is distributed in the hope that it will be useful, but WITHOUT ANY

// WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS

// FOR A PARTICULAR PURPOSE. See the GNU Affero General Public License for more

// details.

//

// You should have received a copy of the GNU Affero General Public License

// along with MuPDF. If not, see <https://www.gnu.org/licenses/agpl-3.0.en.html>

//

// Alternative licensing terms are available from the licensor.

// For commercial licensing, see <https://www.artifex.com/> or contact

// Artifex Software, Inc., 39 Mesa Street, Suite 108A, San Francisco,

// CA 94129, USA, for further information.

#include "mupdf/fitz.h"

#include "context-imp.h"

#include <assert.h>

#include <string.h>

#include <stdio.h>

#include <time.h>

struct fz_style_context

{

  int refs;

  char *user_css;

  int use_document_css;

};

static void fz_new_style_context(fz_context *ctx)

{

  if (ctx)

  {

    ctx->style = fz_malloc_struct(ctx, fz_style_context);

    ctx->style->refs = 1;

    ctx->style->user_css = NULL;

    ctx->style->use_document_css = 1;

  }

}

static fz_style_context *fz_keep_style_context(fz_context *ctx)

{

  if (!ctx)

    return NULL;

  return fz_keep_imp(ctx, ctx->style, &ctx->style->refs);

}

static void fz_drop_style_context(fz_context *ctx)

{

  if (!ctx)

    return;

  if (fz_drop_imp(ctx, ctx->style, &ctx->style->refs))

  {

    fz_free(ctx, ctx->style->user_css);

    fz_free(ctx, ctx->style);

  }

}

void fz_set_use_document_css(fz_context *ctx, int use)

{

  ctx->style->use_document_css = use;

}

int fz_use_document_css(fz_context *ctx)

{

  return ctx->style->use_document_css;

}

void fz_set_user_css(fz_context *ctx, const char *user_css)

{

  fz_free(ctx, ctx->style->user_css);

  ctx->style->user_css = user_css ? fz_strdup(ctx, user_css) : NULL;

}

const char *fz_user_css(fz_context *ctx)

{

  return ctx->style->user_css;

}

void fz_load_user_css(fz_context *ctx, const char *filename)

{

  fz_buffer *buf = NULL;

  fz_var(buf);

  fz_try(ctx)

  {

    buf = fz_read_file(ctx, filename);

    fz_set_user_css(ctx, fz_string_from_buffer(ctx, buf));

  }

  fz_always(ctx)

  {

    fz_drop_buffer(ctx, buf);

  }

  fz_catch(ctx)

  {

    fz_report_error(ctx);

    fz_warn(ctx, "cannot read user css file");

  }

}

static void fz_new_tuning_context(fz_context *ctx)

{

  if (ctx)

  {

    ctx->tuning = fz_malloc_struct(ctx, fz_tuning_context);

    ctx->tuning->refs = 1;

    ctx->tuning->image_decode = fz_default_image_decode;

    ctx->tuning->image_scale = fz_default_image_scale;

  }

}

static fz_tuning_context *fz_keep_tuning_context(fz_context *ctx)

{

  if (!ctx)

    return NULL;

  return fz_keep_imp(ctx, ctx->tuning, &ctx->tuning->refs);

}

static void fz_drop_tuning_context(fz_context *ctx)

{

  if (!ctx)

    return;

  if (fz_drop_imp(ctx, ctx->tuning, &ctx->tuning->refs))

  {

    fz_free(ctx, ctx->tuning);

  }

}

void fz_tune_image_decode(fz_context *ctx, fz_tune_image_decode_fn *image_decode, void *arg)

{

  ctx->tuning->image_decode = image_decode ? image_decode : fz_default_image_decode;

  ctx->tuning->image_decode_arg = arg;

}

void fz_tune_image_scale(fz_context *ctx, fz_tune_image_scale_fn *image_scale, void *arg)

{

  ctx->tuning->image_scale = image_scale ? image_scale : fz_default_image_scale;

  ctx->tuning->image_scale_arg = arg;

}

static void fz_init_random_context(fz_context *ctx)

{

  if (!ctx)

    return;

  ctx->seed48[0] = 0;

  ctx->seed48[1] = 0;

  ctx->seed48[2] = 0;

  ctx->seed48[3] = 0xe66d;

  ctx->seed48[4] = 0xdeec;

  ctx->seed48[5] = 0x5;

  ctx->seed48[6] = 0xb;

  fz_srand48(ctx, (uint32_t)time(NULL));

}

void

fz_drop_context(fz_context *ctx)

{

  int free_master = 0;

  int call_log = 0;

  if (!ctx)

    return;

  if (ctx->error.errcode)

  {

    fz_flush_warnings(ctx);

    fz_warn(ctx, "UNHANDLED EXCEPTION!");

    fz_report_error(ctx);

#ifdef CLUSTER

    abort();

#endif

  }

  assert(ctx->master);

  fz_lock(ctx, FZ_LOCK_ALLOC);

  ctx->master->context_count--;

  if (ctx->master->context_count == 0)

  {

    call_log = 1;

    if (ctx->master != ctx)

      free_master = 1;

  }

  fz_unlock(ctx, FZ_LOCK_ALLOC);

  /* We call the log with ctx intact, apart from the master

   * pointer having had the context_count reduced. The

   * only possible problem here is if fz_log_activity

   * clones the context, but it really shouldn't be doing

   * that! */

  if (call_log)

    fz_log_activity(ctx, FZ_ACTIVITY_SHUTDOWN, NULL);

  if (free_master)

    ctx->alloc.free(ctx->alloc.user, ctx->master);

  /* Other finalisation calls go here (in reverse order) */

  fz_drop_document_handler_context(ctx);

  fz_drop_archive_handler_context(ctx);

  fz_drop_glyph_cache_context(ctx);

  fz_drop_store_context(ctx);

  fz_drop_style_context(ctx);

  fz_drop_tuning_context(ctx);

  fz_drop_colorspace_context(ctx);

  fz_drop_font_context(ctx);

  fz_flush_warnings(ctx);

  assert(ctx->error.top == ctx->error.stack_base);

  /* Free the context itself */

  if (ctx->master == ctx && ctx->context_count != 0)

  {

    /* Need to delay our freeing until all our children have died. */

    ctx->master = NULL;

  }

  else

  {

    ctx->alloc.free(ctx->alloc.user, ctx);

  }

}

static void

fz_init_error_context(fz_context *ctx)

{

#define ALIGN(addr, align)  ((((intptr_t)(addr)) + (align-1)) & ~(align-1))

  ctx->error.stack_base = (fz_error_stack_slot *)ALIGN(ctx->error.stack, FZ_JMPBUF_ALIGN);

  ctx->error.top = ctx->error.stack_base;

  ctx->error.errcode = FZ_ERROR_NONE;

  ctx->error.message[0] = 0;

  ctx->warn.message[0] = 0;

  ctx->warn.count = 0;

}

fz_context *

fz_new_context_imp(const fz_alloc_context *alloc, const fz_locks_context *locks, size_t max_store, const char *version)

{

  fz_context *ctx;

  if (strcmp(version, FZ_VERSION))

  {

    fprintf(stderr, "cannot create context: incompatible header (%s) and library (%s) versions\n", version, FZ_VERSION);

    return NULL;

  }

  if (!alloc)

    alloc = &fz_alloc_default;

  if (!locks)

    locks = &fz_locks_default;

  ctx = Memento_label(alloc->malloc(alloc->user, sizeof(fz_context)), "fz_context");

  if (!ctx)

  {

    fprintf(stderr, "cannot create context (phase 1)\n");

    return NULL;

  }

  memset(ctx, 0, sizeof *ctx);

  ctx->user = NULL;

  ctx->alloc = *alloc;

  ctx->locks = *locks;

  /* We are our own master! */

  ctx->master = ctx;

  ctx->context_count = 1;

  ctx->error.print = fz_default_error_callback;

  ctx->warn.print = fz_default_warning_callback;

  fz_init_error_context(ctx);

  fz_init_aa_context(ctx);

  fz_init_random_context(ctx);

  /* Now initialise sections that are shared */

  fz_try(ctx)

  {

    fz_new_store_context(ctx, max_store);

    fz_new_glyph_cache_context(ctx);

    fz_new_colorspace_context(ctx);

    fz_new_font_context(ctx);

    fz_new_document_handler_context(ctx);

    fz_new_archive_handler_context(ctx);

    fz_new_style_context(ctx);

    fz_new_tuning_context(ctx);

  }

  fz_catch(ctx)

  {

    fz_report_error(ctx);

    fprintf(stderr, "cannot create context (phase 2)\n");

    fz_drop_context(ctx);

    return NULL;

  }

  return ctx;

}

fz_context *

fz_clone_context(fz_context *ctx)

{

  fz_context *new_ctx;

  /* We cannot safely clone the context without having locking/

   * unlocking functions. */

  if (ctx == NULL || (ctx->locks.lock == fz_locks_default.lock && ctx->locks.unlock == fz_locks_default.unlock))

    return NULL;

  new_ctx = ctx->alloc.malloc(ctx->alloc.user, sizeof(fz_context));

  if (!new_ctx)

    return NULL;

  fz_lock(ctx, FZ_LOCK_ALLOC);

  ctx->master->context_count++;

  fz_unlock(ctx, FZ_LOCK_ALLOC);

  new_ctx->master = ctx->master;

  /* First copy old context, including pointers to shared contexts */

  memcpy(new_ctx, ctx, sizeof (fz_context));

  /* Reset error context to initial state. */

  fz_init_error_context(new_ctx);

  /* Then keep lock checking happy by keeping shared contexts with new context */

  fz_keep_document_handler_context(new_ctx);

  fz_keep_archive_handler_context(new_ctx);

  fz_keep_style_context(new_ctx);

  fz_keep_tuning_context(new_ctx);

  fz_keep_font_context(new_ctx);

  fz_keep_colorspace_context(new_ctx);

  fz_keep_store_context(new_ctx);

  fz_keep_glyph_cache(new_ctx);

  return new_ctx;

}

void fz_set_user_context(fz_context *ctx, void *user)

{

  if (ctx != NULL)

    ctx->user = user;

}

void *fz_user_context(fz_context *ctx)

{

  if (ctx == NULL)

    return NULL;

  return ctx->user;

}

void fz_register_activity_logger(fz_context *ctx, fz_activity_fn *activity, void *opaque)

{

  if (ctx == NULL)

    return;

  ctx->activity.activity = activity;

  ctx->activity.opaque = opaque;

}

void fz_log_activity(fz_context *ctx, fz_activity_reason reason, void *arg)

{

  if (ctx == NULL || ctx->activity.activity == NULL)

    return;

  ctx->activity.activity(ctx, ctx->activity.opaque, reason, arg);

}