/*!
The MIT License (MIT)

Copyright (c) 2016 Dmitriy Kubyshkin <dmitriy@kubyshkin.name>

Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all
copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
SOFTWARE.
*/

#ifndef BDD_FOR_C_H
#define BDD_FOR_C_H

#ifdef _WIN32
  #include <stdio.h>
  #include <Windows.h>
  #include <io.h>
  #define __BDD_IS_ATTY__() _isatty(_fileno(stdout))
#else
  #ifndef _POSIX_C_SOURCE
    // This definition is required for `fileno` to be defined
    #define _POSIX_C_SOURCE 200809
  #endif
  #include <stdio.h>
  #include <unistd.h>
  #include <term.h>
  #define __BDD_IS_ATTY__() isatty(fileno(stdout))
#endif

#include <stddef.h>
#include <stdarg.h>
#include <stdlib.h>
#include <string.h>
#include <stdbool.h>

#ifdef _MSC_VER
#pragma warning(push)
#pragma warning(disable: 4996) // _CRT_SECURE_NO_WARNINGS
#endif

#ifndef BDD_USE_COLOR
#define BDD_USE_COLOR 1
#endif

#ifndef BDD_USE_TAP
#define BDD_USE_TAP 0
#endif

#define __BDD_COLOR_RESET__       "\x1B[0m"
#define __BDD_COLOR_RED__         "\x1B[31m"
#define __BDD_COLOR_GREEN__       "\x1B[32m"
#define __BDD_COLOR_YELLOW__       "\x1B[33m"
#define __BDD_COLOR_BOLD__        "\x1B[1m"  // Bold White
#define __BDD_COLOR_MAGENTA__     "\x1B[35m"

typedef struct __bdd_array__ {
    void **values;
    size_t capacity;
    size_t size;
} __bdd_array__;

__bdd_array__ *__bdd_array_create__() {
    __bdd_array__ *arr = malloc(sizeof(__bdd_array__));
    if (!arr) {
        perror("malloc(array)");
        abort();
    }
    arr->capacity = 4;
    arr->size = 0;
    arr->values = calloc(arr->capacity, sizeof(void *));
    return arr;
}

void *__bdd_array_push__(__bdd_array__ *arr, void *item) {
    if (arr->size == arr->capacity) {
        arr->capacity *= 2;
        void *v = realloc(arr->values, sizeof(void*) * arr->capacity);
        if (!v) {
            perror("realloc(array)");
            abort();
        }
        arr->values = v;
    }
    arr->values[arr->size++] = item;
    return item;
}

void *__bdd_array_last__(__bdd_array__ *arr) {
    if (arr->size == 0) {
        return NULL;
    }
    return arr->values[arr->size - 1];
}

void *__bdd_array_pop__(__bdd_array__ *arr) {
    if (arr->size == 0) {
        return NULL;
    }
    void *result = arr->values[arr->size - 1];
    --arr->size;
    return result;
}

void __bdd_array_free__(__bdd_array__ *arr) {
    free(arr->values);
    free(arr);
}

typedef enum __bdd_node_type__ {
    __BDD_NODE_GROUP__ = 1,
    __BDD_NODE_TEST__ = 2,
    __BDD_NODE_INTERIM__ = 3
} __bdd_node_type__;

typedef enum __bdd_node_flags__ {
  __bdd_node_flags_none__  = 0,
  __bdd_node_flags_focus__ = 1 << 0,
  __bdd_node_flags_skip__  = 1 << 1,
} __bdd_node_flags__;

typedef struct __bdd_test_step__ {
    size_t level;
    int id;
    char *name;
    __bdd_node_type__ type;
    __bdd_node_flags__ flags;
} __bdd_test_step__;

typedef struct __bdd_node__ {
    int id;
    int next_node_id;
    char *name;
    __bdd_node_flags__ flags;
    __bdd_node_type__ type;
    __bdd_array__ *list_before;
    __bdd_array__ *list_after;
    __bdd_array__ *list_before_each;
    __bdd_array__ *list_after_each;
    __bdd_array__ *list_children;
} __bdd_node__;

enum __bdd_run_type__ {
    __BDD_INIT_RUN__ = 1,
    __BDD_TEST_RUN__ = 2
};

typedef struct __bdd_config_type__ {
    enum __bdd_run_type__ run;
    int id;
    size_t test_index;
    size_t test_tap_index;
    size_t failed_test_count;
    __bdd_test_step__ *current_test;
    __bdd_array__ *node_stack;
    __bdd_array__ *nodes;
    char *error;
    char *location;
    bool use_color;
    bool use_tap;
    bool has_focus_nodes;
} __bdd_config_type__;

__bdd_test_step__ *__bdd_test_step_create__(size_t level, __bdd_node__ *node) {
    __bdd_test_step__ *step = malloc(sizeof(__bdd_test_step__));
    if (!step) {
        perror("malloc(step)");
        abort();
    }
    step->id = node->id;
    step->level = level;
    step->type = node->type;
    step->name = node->name;
    step->flags = node->flags;
    return step;
}

__bdd_node__ *__bdd_node_create__(int id, char *name, __bdd_node_type__ type, __bdd_node_flags__ flags) {
    __bdd_node__ *n = malloc(sizeof(__bdd_node__));
    if (!n) {
        perror("malloc(node)");
        abort();
    }
    n->id = id;
    n->next_node_id = id + 1;
    n->name = name; // node takes ownership of name
    n->type = type;
    n->flags = flags;
    n->list_before = __bdd_array_create__();
    n->list_after = __bdd_array_create__();
    n->list_before_each = __bdd_array_create__();
    n->list_after_each = __bdd_array_create__();
    n->list_children = __bdd_array_create__();
    return n;
}

bool __bdd_node_is_leaf__(__bdd_node__ *node) {
    return node->list_children->size == 0;
}

void __bdd_node_flatten_internal__(
    __bdd_config_type__ *config,
    size_t level,
    __bdd_node__ *node,
    __bdd_array__  *steps,
    __bdd_array__  *before_each_lists,
    __bdd_array__  *after_each_lists
) {
    if (__bdd_node_is_leaf__(node)) {
        if (config->has_focus_nodes && !(node->flags & __bdd_node_flags_focus__)) {
            return;
        }

        for (size_t listIndex = 0; listIndex < before_each_lists->size; ++listIndex) {
            __bdd_array__ *list = before_each_lists->values[listIndex];
            for (size_t i = 0; i < list->size; ++i) {
                __bdd_array_push__(steps, __bdd_test_step_create__(level, list->values[i]));
            }
        }

        __bdd_array_push__(steps, __bdd_test_step_create__(level, node));

        for (size_t listIndex = 0; listIndex < after_each_lists->size; ++listIndex) {
            size_t reverseListIndex = after_each_lists->size - listIndex - 1;
            __bdd_array__ *list = after_each_lists->values[reverseListIndex];
            for (size_t i = 0; i < list->size; ++i) {
                __bdd_array_push__(steps, __bdd_test_step_create__(level, list->values[i]));
            }
        }
        return;
    }

    __bdd_array_push__(steps, __bdd_test_step_create__(level, node));

    for (size_t i = 0; i < node->list_before->size; ++i) {
        __bdd_array_push__(steps, __bdd_test_step_create__(level + 1, node->list_before->values[i]));
    }

    __bdd_array_push__(before_each_lists, node->list_before_each);
    __bdd_array_push__(after_each_lists, node->list_after_each);

    for (size_t i = 0; i < node->list_children->size; ++i) {
        __bdd_node_flatten_internal__(
          config, level + 1, node->list_children->values[i], steps, before_each_lists, after_each_lists
        );
    }

    __bdd_array_pop__(before_each_lists);
    __bdd_array_pop__(after_each_lists);

    for (size_t i = 0; i < node->list_after->size; ++i) {
        __bdd_array_push__(steps, __bdd_test_step_create__(level + 1, node->list_after->values[i]));
    }
}

__bdd_array__ *__bdd_node_flatten__(__bdd_config_type__ *config, __bdd_node__ *node, __bdd_array__ *steps) {
    if (node == NULL) {
        return steps;
    }

    __bdd_array__ *before_each_lists = __bdd_array_create__();
    __bdd_array__ *after_each_lists = __bdd_array_create__();
    __bdd_node_flatten_internal__(config, 0, node, steps, before_each_lists, after_each_lists);
    __bdd_array_free__(before_each_lists);
    __bdd_array_free__(after_each_lists);

    return steps;
}

void __bdd_node_free__(__bdd_node__ *n) {
    free(n->name);
    __bdd_array_free__(n->list_before);
    __bdd_array_free__(n->list_after);
    __bdd_array_free__(n->list_before_each);
    __bdd_array_free__(n->list_after_each);
    __bdd_array_free__(n->list_children);
    free(n);
}

char *__bdd_spec_name__;
void __bdd_test_main__(__bdd_config_type__ *__bdd_config__);
char *__bdd_vformat__(const char *format, va_list va);

void __bdd_indent__(FILE *fp, size_t level) {
    for (size_t i = 0; i < level; ++i) {
        fprintf(fp, "  ");
    }
}

bool __bdd_enter_node__(__bdd_node_flags__ node_flags, __bdd_config_type__ *config, __bdd_node_type__ type, ptrdiff_t list_offset, char *fmt, ...) {
    va_list va;
    va_start(va, fmt);
    char *name = __bdd_vformat__(fmt, va);
    va_end(va);

    if (config->run == __BDD_INIT_RUN__) {
        __bdd_node__ *top = __bdd_array_last__(config->node_stack);
        __bdd_array__ *list = *(__bdd_array__ **)((unsigned char *)top + list_offset);

        int id = config->id++;
        __bdd_node__ *node = __bdd_node_create__(id, name, type, node_flags);
        if (node_flags & __bdd_node_flags_focus__) {
            // Propagate focus to group nodes up the tree to print inly them
            top->flags |= node_flags & __bdd_node_flags_focus__;
            config->has_focus_nodes = true;
        }
        __bdd_array_push__(list, node);
        __bdd_array_push__(config->nodes, node);
        if (type == __BDD_NODE_GROUP__) {
            __bdd_array_push__(config->node_stack, node);
            return true;
        }
        return false;
    }

    if (config->id >= (int)config->nodes->size) {
        fprintf(stderr, "non-deterministic spec\n");
        abort();
    }
    __bdd_node__ *node = config->nodes->values[config->id];
    if (node->type != type || strcmp(node->name, name) != 0) {
        fprintf(stderr, "non-deterministic spec\n");
        abort();
    }
    free(name);

    __bdd_test_step__ *step = config->current_test;
    bool should_enter = step->id >= node->id && step->id < node->next_node_id;
    if (should_enter) {
        __bdd_array_push__(config->node_stack, node);
        config->id++;
    } else {
        config->id = node->next_node_id;
    }
#if defined(BDD_PRINT_TRACE)
    const char *color = config->use_color ? __BDD_COLOR_MAGENTA__ : "";
    fprintf(stderr, "%s% 3d ", color, step->id);
    __bdd_indent__(stderr, config->node_stack->size - 1 - (int)should_enter);
    const char *reset = config->use_color ? __BDD_COLOR_RESET__ : "";
    fprintf(stderr,
        "%s [%d, %d) %s%s\n",
        should_enter ? ">" : "|",
        node->id,
        node->next_node_id,
        node->name,
        reset);
#endif
    return should_enter;
}

void __bdd_exit_node__(__bdd_config_type__ *config) {
    __bdd_node__ *top = __bdd_array_pop__(config->node_stack);
    if (config->run == __BDD_INIT_RUN__) {
        top->next_node_id = config->id;
    }
}

void __bdd_run__(__bdd_config_type__ *config) {
    __bdd_test_step__ *step = config->current_test;

    if (step->type == __BDD_NODE_GROUP__ && !config->use_tap) {
        if (config->has_focus_nodes && !(step->flags & __bdd_node_flags_focus__)) {
            return;
        }
        __bdd_indent__(stdout, step->level);
        printf(
            "%s%s%s\n",
            config->use_color ? __BDD_COLOR_BOLD__ : "",
            step->name,
            config->use_color ? __BDD_COLOR_RESET__ : ""
        );
        return;
    }

    bool skipped = false;
    if (step->type == __BDD_NODE_TEST__) {
        if (config->has_focus_nodes && !(step->flags & __bdd_node_flags_focus__)) {
          skipped = true;
        } else if (step->flags & __bdd_node_flags_skip__) {
          skipped = true;
        }
        ++config->test_tap_index;
        // Print the step name before running the test so it is visible
        // even if the test itself crashes.
        if ((!skipped || !config->has_focus_nodes) && config->run == __BDD_TEST_RUN__ && !config->use_tap) {
          __bdd_indent__(stdout, step->level);
          printf("%s ", step->name);
        }

        if (!skipped) {
          __bdd_test_main__(config);
        }

        if (skipped) {
            if (config->run == __BDD_TEST_RUN__) {
                if (!config->has_focus_nodes) {
                  if (config->use_tap) {
                      // We only to report tests and not setup / teardown success
                      if (config->test_tap_index) {
                          printf("skipped %zu - %s\n", config->test_tap_index, step->name);
                      }
                  } else {
                      printf(
                          "%s(SKIP)%s\n",
                          config->use_color ? __BDD_COLOR_YELLOW__ : "",
                          config->use_color ? __BDD_COLOR_RESET__ : ""
                      );
                  }
                }
            }
        } else if (config->error == NULL) {
            if (config->run == __BDD_TEST_RUN__) {
                if (config->use_tap) {
                    // We only to report tests and not setup / teardown success
                    if (config->test_tap_index) {
                        printf("ok %zu - %s\n", config->test_tap_index, step->name);
                    }
                } else {
                    printf(
                        "%s(OK)%s\n",
                        config->use_color ? __BDD_COLOR_GREEN__ : "",
                        config->use_color ? __BDD_COLOR_RESET__ : ""
                    );
                }
            }
        } else {
            ++config->failed_test_count;
            if (config->use_tap) {
                // We only to report tests and not setup / teardown errors
                if (config->test_tap_index) {
                    printf("not ok %zu - %s\n", config->test_tap_index, step->name);
                }
            } else {
                printf(
                    "%s(FAIL)%s\n",
                    config->use_color ? __BDD_COLOR_RED__ : "",
                    config->use_color ? __BDD_COLOR_RESET__ : ""
                );
                __bdd_indent__(stdout, step->level + 1);
                printf("%s\n", config->error);
                __bdd_indent__(stdout, step->level + 2);
                printf("%s\n", config->location);
            }
            free(config->error);
            config->error = NULL;
        }
    } else if (!skipped) {
      __bdd_test_main__(config);
    }
}

char *__bdd_vformat__(const char *format, va_list va) {
    // First we over-allocate
    const size_t size = 2048;
    char *result = calloc(size, sizeof(char));
    if (!result) {
        perror("calloc(result)");
        abort();
    }
    vsnprintf(result, size - 1, format, va);

    // Then clip to an actual size
    void* r = realloc(result, strlen(result) + 1);
    if (!r) {
        perror("realloc(result)");
        abort();
    }
    result = r;
    return result;
}

char *__bdd_format__(const char *format, ...) {
    va_list va;
    va_start(va, format);
    char *result = __bdd_vformat__(format, va);
    va_end(va);
    return result;
}

bool __bdd_is_supported_term__() {
    bool result;
    const char *term = getenv("TERM");
    result = term && strcmp(term, "") != 0;
#ifndef _WIN32
    return result;
#else
    if (result) {
        return 1;
    }

    // Attempt to enable virtual terminal processing on Windows.
    // See: https://msdn.microsoft.com/en-us/library/windows/desktop/mt638032(v=vs.85).aspx
    HANDLE hOut = GetStdHandle(STD_OUTPUT_HANDLE);
    if (hOut == INVALID_HANDLE_VALUE) {
        return 0;
    }

    DWORD dwMode = 0;
    if (!GetConsoleMode(hOut, &dwMode)) {
        return 0;
    }

    dwMode |= 0x4; // ENABLE_VIRTUAL_TERMINAL_PROCESSING
    if (!SetConsoleMode(hOut, dwMode)) {
        return 0;
    }

    return 1;
#endif
}

int main(void) {
    struct __bdd_config_type__ config = {
        .run = __BDD_INIT_RUN__,
        .id = 0,
        .test_index = 0,
        .test_tap_index = 0,
        .failed_test_count = 0,
        .node_stack = __bdd_array_create__(),
        .nodes = __bdd_array_create__(),
        .error = NULL,
        .use_color = 0,
        .use_tap = 0
    };

    const char *tap_env = getenv("BDD_USE_TAP");
    if (BDD_USE_TAP || (tap_env && strcmp(tap_env, "") != 0 && strcmp(tap_env, "0") != 0)) {
        config.use_tap = 1;
    }

    if (!config.use_tap && BDD_USE_COLOR && __BDD_IS_ATTY__() && __bdd_is_supported_term__()) {
        config.use_color = 1;
    }

    __bdd_node__ *root = __bdd_node_create__(-1, __bdd_spec_name__, __BDD_NODE_GROUP__, __bdd_node_flags_none__);
    __bdd_array_push__(config.node_stack, root);

    // During the first run we just gather the
    // count of the tests and their descriptions
    __bdd_test_main__(&config);

    __bdd_array__ *steps = __bdd_array_create__();
    __bdd_node_flatten__(&config, root, steps);

    size_t test_count = 0;
    for (size_t i = 0; i < steps->size; ++i) {
        __bdd_test_step__ *step = steps->values[i];
        if(step->type == __BDD_NODE_TEST__) {
            ++test_count;
        }
    }

    // Outputting the name of the suite
    if (config.use_tap) {
        printf("TAP version 13\n1..%zu\n", test_count);
    }

    config.run = __BDD_TEST_RUN__;

    for (size_t i = 0; i < steps->size; ++i) {
        __bdd_test_step__ *step = steps->values[i];
        config.node_stack->size = 1;
        config.id = 0;
        config.current_test = step;
        __bdd_run__(&config);
    }

    for (size_t i = 0; i < config.nodes->size; ++i) {
        __bdd_node_free__(config.nodes->values[i]);
    }
    root->name = NULL; // name is statically allocated
    __bdd_node_free__(root);
    for (size_t i = 0; i < steps->size; ++i) {
        free(steps->values[i]);
    }
    __bdd_array_free__(config.nodes);
    __bdd_array_free__(config.node_stack);
    __bdd_array_free__(steps);

    if (config.failed_test_count > 0) {
        if (!config.use_tap) {
            printf(
                "\n%zu test%s run, %zu failed.\n",
                test_count, test_count == 1 ? "" : "s", config.failed_test_count
            );
        }
        return 1;
    }
    return 0;
}

#define spec(name) \
char *__bdd_spec_name__ = (name);\
void __bdd_test_main__ (__bdd_config_type__ *__bdd_config__)\

#define __BDD_NODE__(flags, node_list, type, ...)\
for(\
    bool __bdd_has_run__ = 0;\
    (\
      !__bdd_has_run__ && \
      __bdd_enter_node__(flags, __bdd_config__, (type), offsetof(struct __bdd_node__, node_list), __VA_ARGS__) \
    );\
    __bdd_exit_node__(__bdd_config__), \
    __bdd_has_run__ = 1 \
)

#define describe(...) __BDD_NODE__(__bdd_node_flags_none__, list_children, __BDD_NODE_GROUP__, __VA_ARGS__)
#define it(...)       __BDD_NODE__(__bdd_node_flags_none__, list_children, __BDD_NODE_TEST__, __VA_ARGS__)
#define it_only(...)  __BDD_NODE__(__bdd_node_flags_focus__, list_children, __BDD_NODE_TEST__, __VA_ARGS__)
#define fit(...)      it_only(__VA_ARGS__)
#define it_skip(...)  __BDD_NODE__(__bdd_node_flags_skip__, list_children, __BDD_NODE_TEST__, __VA_ARGS__)
#define xit(...)      it_skip(__VA_ARGS__)
#define before_each() __BDD_NODE__(__bdd_node_flags_none__, list_before_each, __BDD_NODE_INTERIM__, "before_each")
#define after_each()  __BDD_NODE__(__bdd_node_flags_none__, list_after_each, __BDD_NODE_INTERIM__, "after_each")
#define before()      __BDD_NODE__(__bdd_node_flags_none__, list_before, __BDD_NODE_INTERIM__, "before")
#define after()       __BDD_NODE__(__bdd_node_flags_none__, list_after, __BDD_NODE_INTERIM__, "after")

#ifndef BDD_NO_CONTEXT_KEYWORD
#define context(name) describe(name)
#endif

#define __BDD_MACRO__(M, ...) __BDD_OVERLOAD__(M, __BDD_COUNT_ARGS__(__VA_ARGS__)) (__VA_ARGS__)
#define __BDD_OVERLOAD__(macro_name, suffix) __BDD_EXPAND_OVERLOAD__(macro_name, suffix)
#define __BDD_EXPAND_OVERLOAD__(macro_name, suffix) macro_name##suffix

#define __BDD_COUNT_ARGS__(...) __BDD_PATTERN_MATCH__(__VA_ARGS__,_,_,_,_,_,_,_,_,_,ONE__)
#define __BDD_PATTERN_MATCH__(_1,_2,_3,_4,_5,_6,_7,_8,_9,_10,N, ...) N

#define __BDD_STRING_HELPER__(x) #x
#define __BDD_STRING__(x) __BDD_STRING_HELPER__(x)
#define __STRING__LINE__ __BDD_STRING__(__LINE__)

#define __BDD_FMT_COLOR__ __BDD_COLOR_RED__ "Check failed:" __BDD_COLOR_RESET__ " %s"
#define __BDD_FMT_PLAIN__ "Check failed: %s"

#define __BDD_CHECK__(condition, ...) if (!(condition))\
{\
    char *message = __bdd_format__(__VA_ARGS__);\
    const char *fmt = __bdd_config__->use_color ? __BDD_FMT_COLOR__ : __BDD_FMT_PLAIN__;\
    __bdd_config__->location = "at " __FILE__ ":" __STRING__LINE__;\
    size_t bufflen = strlen(fmt) + strlen(message) + 1;\
    __bdd_config__->error = calloc(bufflen, sizeof(char));\
    if (__bdd_config__->use_color) {\
      snprintf(__bdd_config__->error, bufflen, __BDD_FMT_COLOR__, message);\
    } else {\
      snprintf(__bdd_config__->error, bufflen, __BDD_FMT_PLAIN__, message);\
    }\
    free(message);\
    return;\
}

#define __BDD_CHECK_ONE__(condition) __BDD_CHECK__(condition, #condition)

#define check(...) do { __BDD_MACRO__(__BDD_CHECK_, __VA_ARGS__) } while (0)

#ifdef _MSC_VER
#pragma warning(pop)
#endif

#endif //BDD_FOR_C_H