#include "amduat/enc/asl_tgk_exec_plan.h"

#include <stdbool.h>
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

enum {
  k_plan_header_size = 8,
  k_params_size = 65,
  k_operator_size = 129,
  k_input_offset = 97
};

static bool read_file(const char *path, uint8_t **out_bytes, size_t *out_len) {
  FILE *fp;
  long size;
  uint8_t *buffer;
  size_t read_len;

  if (path == NULL || out_bytes == NULL || out_len == NULL) {
    return false;
  }
  *out_bytes = NULL;
  *out_len = 0u;

  fp = fopen(path, "rb");
  if (fp == NULL) {
    return false;
  }
  if (fseek(fp, 0, SEEK_END) != 0) {
    fclose(fp);
    return false;
  }
  size = ftell(fp);
  if (size < 0) {
    fclose(fp);
    return false;
  }
  if (fseek(fp, 0, SEEK_SET) != 0) {
    fclose(fp);
    return false;
  }

  buffer = (uint8_t *)malloc((size_t)size + 1u);
  if (buffer == NULL) {
    fclose(fp);
    return false;
  }
  read_len = fread(buffer, 1u, (size_t)size, fp);
  fclose(fp);
  if (read_len != (size_t)size) {
    free(buffer);
    return false;
  }
  buffer[size] = '\0';

  *out_bytes = buffer;
  *out_len = (size_t)size;
  return true;
}

static bool build_fixture_path(char *out, size_t out_len) {
  const char *needle = "/tests/enc/";
  const char *path = __FILE__;
  const char *pos = strstr(path, needle);
  size_t prefix_len;

  if (pos == NULL) {
    return false;
  }
  prefix_len = (size_t)(pos - path);
  if (prefix_len + strlen("/tests/fixtures/conformance/"
                          "asl_tgk_exec_plan/artifacts/plan0.bin") + 1u >
      out_len) {
    return false;
  }

  memcpy(out, path, prefix_len);
  out[prefix_len] = '\0';
  strcat(out, "/tests/fixtures/conformance/"
              "asl_tgk_exec_plan/artifacts/plan0.bin");
  return true;
}

static void store_u32_le(uint8_t *out, uint32_t value) {
  out[0] = (uint8_t)(value & 0xffu);
  out[1] = (uint8_t)((value >> 8) & 0xffu);
  out[2] = (uint8_t)((value >> 16) & 0xffu);
  out[3] = (uint8_t)((value >> 24) & 0xffu);
}

static void fill_default_params(amduat_asl_tgk_exec_operator_params_t *params) {
  memset(params, 0, sizeof(*params));
  params->tgk_traversal.direction = 1u;
}

static int test_round_trip(void) {
  amduat_asl_tgk_exec_operator_def_t operators[2];
  amduat_asl_tgk_exec_plan_t plan;
  amduat_octets_t encoded;
  amduat_asl_tgk_exec_plan_t decoded;
  int exit_code = 1;

  memset(operators, 0, sizeof(operators));
  fill_default_params(&operators[0].params);
  fill_default_params(&operators[1].params);

  operators[0].op_id = 1u;
  operators[0].op_type = AMDUAT_ASL_TGK_EXEC_OP_SEGMENT_SCAN;
  operators[0].flags = AMDUAT_ASL_TGK_EXEC_OP_FLAG_NONE;
  operators[0].snapshot.logseq_min = 0u;
  operators[0].snapshot.logseq_max = 10u;
  operators[0].input_count = 0u;

  operators[1].op_id = 2u;
  operators[1].op_type = AMDUAT_ASL_TGK_EXEC_OP_TGK_TRAVERSAL;
  operators[1].flags = AMDUAT_ASL_TGK_EXEC_OP_FLAG_PARALLEL;
  operators[1].snapshot.logseq_min = 1u;
  operators[1].snapshot.logseq_max = 10u;
  operators[1].params.tgk_traversal.direction = 2u;
  operators[1].params.tgk_traversal.traversal_depth = 3u;
  operators[1].params.tgk_traversal.start_node_id = 42u;
  operators[1].input_count = 1u;
  operators[1].inputs[0] = 1u;

  plan.plan_version = AMDUAT_ASL_TGK_EXEC_PLAN_VERSION;
  plan.operator_count = 2u;
  plan.operators = operators;

  if (!amduat_enc_asl_tgk_exec_plan_encode_v1(&plan, &encoded)) {
    fprintf(stderr, "encode failed\n");
    return exit_code;
  }

  if (!amduat_enc_asl_tgk_exec_plan_decode_v1(encoded, &decoded)) {
    fprintf(stderr, "decode failed\n");
    goto cleanup;
  }

  if (decoded.plan_version != plan.plan_version ||
      decoded.operator_count != plan.operator_count) {
    fprintf(stderr, "header mismatch\n");
    goto cleanup_decoded;
  }
  if (decoded.operators[1].op_type != operators[1].op_type ||
      decoded.operators[1].params.tgk_traversal.direction != 2u ||
      decoded.operators[1].params.tgk_traversal.traversal_depth != 3u ||
      decoded.operators[1].params.tgk_traversal.start_node_id != 42u) {
    fprintf(stderr, "operator fields mismatch\n");
    goto cleanup_decoded;
  }
  if (decoded.operators[1].input_count != 1u ||
      decoded.operators[1].inputs[0] != 1u) {
    fprintf(stderr, "inputs mismatch\n");
    goto cleanup_decoded;
  }

  exit_code = 0;

cleanup_decoded:
  amduat_enc_asl_tgk_exec_plan_free(&decoded);
cleanup:
  free((void *)encoded.data);
  return exit_code;
}

static int test_invalid_input_ref(void) {
  amduat_asl_tgk_exec_operator_def_t operators[1];
  amduat_asl_tgk_exec_plan_t plan;
  amduat_octets_t encoded;
  int exit_code = 1;
  size_t op_offset;
  size_t input_offset;

  memset(operators, 0, sizeof(operators));
  fill_default_params(&operators[0].params);
  operators[0].op_id = 1u;
  operators[0].op_type = AMDUAT_ASL_TGK_EXEC_OP_SEGMENT_SCAN;
  operators[0].input_count = 0u;

  plan.plan_version = AMDUAT_ASL_TGK_EXEC_PLAN_VERSION;
  plan.operator_count = 1u;
  plan.operators = operators;

  if (!amduat_enc_asl_tgk_exec_plan_encode_v1(&plan, &encoded)) {
    fprintf(stderr, "encode failed\n");
    return exit_code;
  }

  op_offset = k_plan_header_size;
  if (encoded.len < op_offset + k_input_offset + 4u) {
    fprintf(stderr, "encoded buffer too small\n");
    goto cleanup;
  }
  store_u32_le((uint8_t *)encoded.data + op_offset + k_params_size + 28u, 1u);
  input_offset = op_offset + k_input_offset;
  store_u32_le((uint8_t *)encoded.data + input_offset, 99u);

  if (amduat_enc_asl_tgk_exec_plan_decode_v1(encoded, &(amduat_asl_tgk_exec_plan_t){0})) {
    fprintf(stderr, "decode unexpectedly succeeded\n");
    goto cleanup;
  }

  exit_code = 0;

cleanup:
  free((void *)encoded.data);
  return exit_code;
}

static int test_truncated_decode(void) {
  amduat_asl_tgk_exec_operator_def_t operators[1];
  amduat_asl_tgk_exec_plan_t plan;
  amduat_octets_t encoded;
  amduat_octets_t truncated;
  int exit_code = 1;

  memset(operators, 0, sizeof(operators));
  fill_default_params(&operators[0].params);
  operators[0].op_id = 1u;
  operators[0].op_type = AMDUAT_ASL_TGK_EXEC_OP_SEGMENT_SCAN;

  plan.plan_version = AMDUAT_ASL_TGK_EXEC_PLAN_VERSION;
  plan.operator_count = 1u;
  plan.operators = operators;

  if (!amduat_enc_asl_tgk_exec_plan_encode_v1(&plan, &encoded)) {
    fprintf(stderr, "encode failed\n");
    return exit_code;
  }

  truncated = amduat_octets(encoded.data, encoded.len - 1u);
  if (amduat_enc_asl_tgk_exec_plan_decode_v1(truncated,
                                            &(amduat_asl_tgk_exec_plan_t){0})) {
    fprintf(stderr, "decode unexpectedly succeeded\n");
    goto cleanup;
  }

  exit_code = 0;

cleanup:
  free((void *)encoded.data);
  return exit_code;
}

static int test_invalid_input_count(void) {
  amduat_asl_tgk_exec_operator_def_t operators[1];
  amduat_asl_tgk_exec_plan_t plan;
  amduat_octets_t encoded;
  int exit_code = 1;
  size_t op_offset;
  size_t input_count_offset;

  memset(operators, 0, sizeof(operators));
  fill_default_params(&operators[0].params);
  operators[0].op_id = 1u;
  operators[0].op_type = AMDUAT_ASL_TGK_EXEC_OP_SEGMENT_SCAN;

  plan.plan_version = AMDUAT_ASL_TGK_EXEC_PLAN_VERSION;
  plan.operator_count = 1u;
  plan.operators = operators;

  if (!amduat_enc_asl_tgk_exec_plan_encode_v1(&plan, &encoded)) {
    fprintf(stderr, "encode failed\n");
    return exit_code;
  }

  op_offset = k_plan_header_size;
  input_count_offset = op_offset + k_params_size + 28u;
  if (encoded.len < input_count_offset + 4u) {
    fprintf(stderr, "encoded buffer too small\n");
    goto cleanup;
  }
  store_u32_le((uint8_t *)encoded.data + input_count_offset, 9u);

  if (amduat_enc_asl_tgk_exec_plan_decode_v1(encoded,
                                            &(amduat_asl_tgk_exec_plan_t){0})) {
    fprintf(stderr, "decode unexpectedly succeeded\n");
    goto cleanup;
  }

  exit_code = 0;

cleanup:
  free((void *)encoded.data);
  return exit_code;
}

static int test_invalid_snapshot_range(void) {
  amduat_asl_tgk_exec_operator_def_t operators[1];
  amduat_asl_tgk_exec_plan_t plan;

  memset(operators, 0, sizeof(operators));
  fill_default_params(&operators[0].params);
  operators[0].op_id = 1u;
  operators[0].op_type = AMDUAT_ASL_TGK_EXEC_OP_SEGMENT_SCAN;
  operators[0].snapshot.logseq_min = 10u;
  operators[0].snapshot.logseq_max = 1u;

  plan.plan_version = AMDUAT_ASL_TGK_EXEC_PLAN_VERSION;
  plan.operator_count = 1u;
  plan.operators = operators;

  if (amduat_enc_asl_tgk_exec_plan_encode_v1(&plan,
                                             &(amduat_octets_t){0})) {
    fprintf(stderr, "encode unexpectedly succeeded\n");
    return 1;
  }
  return 0;
}

static int test_fixture_plan0(void) {
  char path[512];
  uint8_t *bytes = NULL;
  size_t len = 0u;
  amduat_asl_tgk_exec_plan_t plan;
  int exit_code = 1;

  if (!build_fixture_path(path, sizeof(path))) {
    fprintf(stderr, "fixture path build failed\n");
    return exit_code;
  }
  if (!read_file(path, &bytes, &len)) {
    fprintf(stderr, "fixture read failed: %s\n", path);
    return exit_code;
  }

  if (!amduat_enc_asl_tgk_exec_plan_decode_v1(amduat_octets(bytes, len),
                                              &plan)) {
    fprintf(stderr, "fixture decode failed\n");
    goto cleanup;
  }

  if (plan.plan_version != AMDUAT_ASL_TGK_EXEC_PLAN_VERSION ||
      plan.operator_count != 1u ||
      plan.operators[0].op_type != AMDUAT_ASL_TGK_EXEC_OP_SEGMENT_SCAN ||
      plan.operators[0].snapshot.logseq_max != 10u) {
    fprintf(stderr, "fixture contents mismatch\n");
    goto cleanup_plan;
  }

  exit_code = 0;

cleanup_plan:
  amduat_enc_asl_tgk_exec_plan_free(&plan);
cleanup:
  free(bytes);
  return exit_code;
}

int main(void) {
  if (test_round_trip() != 0) {
    return 1;
  }
  if (test_invalid_input_ref() != 0) {
    return 1;
  }
  if (test_truncated_decode() != 0) {
    return 1;
  }
  if (test_invalid_input_count() != 0) {
    return 1;
  }
  if (test_invalid_snapshot_range() != 0) {
    return 1;
  }
  return test_fixture_plan0();
}