#include "ansi_lib.h"
#include <argp.h>
#include <fcntl.h>
#include <readline/history.h>
#include <readline/readline.h>
#include <stdbool.h>
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>

#include "hydroforth/hydroforth.h"

const char *argp_program_version = "hydroforth " HF__VERSION;
const char *argp_program_bug_address = "<dominic@dergrimm.net>";
static char doc[] = "Hydroforth is a minimal Forth interpreter written in C";

static char args_doc[] = "[SRC]";

static struct argp_option options[] = {
    {"debug", 'd', 0, 0, "Prints debug information"},
    {"shell", 's', 0, 0, "Starts Forth interpreter shell"},
    {"output", 'o', "FILE", 0, "Output to FILE instead of standard output"},
    {0},
};

struct arguments {
  char *args[1];
  bool debug;
  bool shell;
  char *output_file;
};

static error_t parse_opt(int key, char *arg, struct argp_state *state) {
  struct arguments *arguments = state->input;

  switch (key) {
  case 'd':
    arguments->debug = true;
    break;

  case 's':
    arguments->shell = true;
    break;

  case 'o':
    arguments->output_file = arg;
    break;

  case ARGP_KEY_ARG:
    if (state->arg_num >= 1)
      /* Too many arguments. */
      argp_usage(state);

    arguments->args[state->arg_num] = arg;

    break;

  case ARGP_KEY_END:
    // if (state->arg_num < 1)
    //   /* Not enough arguments. */
    //   argp_usage(state);
    break;

  default:
    return ARGP_ERR_UNKNOWN;
  }
  return 0;
}

static struct argp argp = {options, parse_opt, args_doc, doc};

bool read_src(FILE *fp, char **src, size_t *const len) {
  if (fseek(fp, 0L, SEEK_END) != 0) {
    fputs("Error seeking to file end!\n", stderr);
    return false;
  }
  const size_t bufsize = ftell(fp);
  if (bufsize == -1) {
    fputs("Error getting file size!\n", stderr);
    return false;
  }
  *len = bufsize != 0 ? bufsize - 1 : 0;
  *src = malloc(sizeof(char) * bufsize);
  if (fseek(fp, 0L, SEEK_SET) != 0) {
    fputs("Error rewinding file to start!\n", stderr);
    return false;
  }
  fread(*src, sizeof(char), bufsize, fp);
  if (ferror(fp) != 0) {
    fputs("Error reading file!\n", stderr);
    return false;
  }

  return true;
}

struct hf__result shell(const struct arguments *const arguments) {
  SET_8_VALUE_COLOUR(TXT_GREEN);
  printf("hydroforth@%s shell\n\n", HF__VERSION);
  SET_8_VALUE_COLOUR(TXT_DEFAULT);

  struct hf__parser parser = {
      .keyword_map = NULL,
      .keyword_map_is_init = false,
  };

  struct hf__interpreter interpreter = {
      .call_stack = malloc(sizeof(struct hf__node) * 10),
      .call_stack_len = 0,
      .call_stack_cap = 10,
      .call_stack_cap_max = HF__INTERPRETER__CALL_STACK_CAP_MAX,

      .words =
          {
              .arr = calloc(HF__INTERPRETER__WORDS_CAP,
                            sizeof(struct hf__hashmap__node *)),
              .cap = HF__INTERPRETER__WORDS_CAP,
          },

      .stack = malloc(sizeof(int) * 10),
      .stack_len = 0,
      .stack_size = 10,

      .is_running = true,
  };

  using_history();

  char *input;
  while ((input = readline("hydroforth> ")) != NULL) {
    if (*input) {
      add_history(input);
    }

    size_t tokens_len = 0;
    size_t tokens_size = 0;
    struct hf__token *tokens = malloc(sizeof(struct hf__token) * tokens_size);
    hf__lex(input, strlen(input), &tokens, &tokens_len, &tokens_size);

    if (tokens_len == 0) {
      continue;
    }

    size_t nodes_len = 0;
    size_t nodes_size = 0;
    struct hf__node *nodes = NULL;
    struct hf__result parse_res = hf__parse(&parser, input, tokens, tokens_len,
                                            &nodes, &nodes_len, &nodes_size);
    free(tokens);
    free(input);
    if (!parse_res.ok) {
      hf__handle_error_light(&parse_res.error);
      putchar('\n');
      continue;
    }

    for (size_t i = nodes_len - 1; i != 0 - 1; i--) {
      hf__parser__node_array_push(&interpreter.call_stack,
                                  &interpreter.call_stack_len,
                                  &interpreter.call_stack_cap, nodes[i]);
    }
    free(nodes);

    SET_8_VALUE_COLOUR(TXT_GREEN);
    printf("=> ");
    SET_8_VALUE_COLOUR(TXT_DEFAULT);
    while (interpreter.call_stack_len != 0 && interpreter.is_running) {
      struct hf__result res = hf__interpreter__run(&interpreter);
      if (!res.ok) {
        hf__handle_error_light(&res.error);
        putchar('\n');
      }
    }
    putchar('\n');

    if (interpreter.stack_len != 0) {
      printf("stack:");
      SET_8_VALUE_COLOUR(TXT_YELLOW);
      for (size_t i = 0; i < interpreter.stack_len; i++) {
        printf(" %i", interpreter.stack[i]);
      }
      SET_8_VALUE_COLOUR(TXT_DEFAULT);
      putchar('\n');
    }

    if (!interpreter.is_running) {
      SET_GRAPHIC_MODE(DIM_MODE);
      printf("\nexiting...\n");
      RESET_GRAPHICS_MODES;
      break;
    }
  }

  // free(interpreter.call_stack);
  // free(interpreter.stack);
  hf__interpreter__free(&interpreter);

  return HF__OK;
}

int main(int argc, char *argv[]) {
  struct arguments arguments;

  arguments.args[0] = NULL;
  arguments.debug = false;
  arguments.shell = false;
  arguments.output_file = NULL;

  argp_parse(&argp, argc, argv, 0, 0, &arguments);

  int fd;
  if (arguments.output_file) {
    fd = open(arguments.output_file, O_WRONLY | O_CREAT, 0644);
    printf("fd = %i\n", fd);
    if (fd == -1) {
      perror("open failed");
      return 1;
    }
    if (dup2(fd, 1) == -1) {
      perror("dup2 failed");
      return 1;
    }
  }

  if (arguments.shell) {
    struct hf__result res = shell(&arguments);

    if (arguments.output_file) {
      close(fd);
    }

    if (!res.ok) {
      hf__handle_error_light(&res.error);
      putchar('\n');
      return 1;
    }
  } else {
    FILE *fp = fopen(arguments.args[0], "r");
    if (fp == NULL) {
      fputs("Error opening file!\n", stderr);
      return 1;
    }
    char *src;
    size_t src_len;
    const bool read_res = read_src(fp, &src, &src_len);
    fclose(fp);
    if (!read_res) {
      fputs("Error reading file!\n", stderr);
      return 1;
    }

    struct hf__parser parser = {
        .keyword_map = NULL,
        .keyword_map_is_init = false,
    };

    struct hf__interpreter interpreter = {
        .call_stack = malloc(sizeof(struct hf__node) * 10),
        .call_stack_len = 0,
        .call_stack_cap = 10,
        .call_stack_cap_max = HF__INTERPRETER__CALL_STACK_CAP_MAX,

        .words =
            {
                .arr = calloc(HF__INTERPRETER__WORDS_CAP,
                              sizeof(struct hf__hashmap__node *)),
                .cap = HF__INTERPRETER__WORDS_CAP,
            },

        .stack = malloc(sizeof(int) * 10),
        .stack_len = 0,
        .stack_size = 10,

        .is_running = true,
    };

    size_t tokens_len = 0;
    size_t tokens_size = 0;
    struct hf__token *tokens = malloc(sizeof(struct hf__token) * tokens_size);
    hf__lex(src, src_len, &tokens, &tokens_len, &tokens_size);

    size_t nodes_len = 0;
    size_t nodes_size = 0;
    struct hf__node *nodes = NULL;
    struct hf__result parse_res = hf__parse(&parser, src, tokens, tokens_len,
                                            &nodes, &nodes_len, &nodes_size);
    if (!parse_res.ok) {
      hf__handle_error_light(&parse_res.error);
      putchar('\n');
      return 1;
    }
    free(tokens);
    free(src);

    for (size_t i = nodes_len - 1; i != 0 - 1; i--) {
      hf__parser__node_array_push(&interpreter.call_stack,
                                  &interpreter.call_stack_len,
                                  &interpreter.call_stack_cap, nodes[i]);
    }
    free(nodes);

    bool err = false;
    while (interpreter.call_stack_len != 0 && interpreter.is_running) {
      struct hf__result res = hf__interpreter__run(&interpreter);
      if (!res.ok) {
        hf__handle_error_light(&res.error);
        putchar('\n');

        if (arguments.debug) {
          SET_8_VALUE_COLOUR(TXT_RED);
          puts("\n=== DEBUG ===");

          SET_8_VALUE_COLOUR(TXT_DEFAULT);
          printf("stack:");
          SET_8_VALUE_COLOUR(TXT_YELLOW);
          for (size_t i = 0; i < interpreter.stack_len; i++) {
            printf(" %i", interpreter.stack[i]);
          }
          SET_8_VALUE_COLOUR(TXT_DEFAULT);
          putchar('\n');
        }

        err = true;
        break;
      }
    }

    if (parser.keyword_map_is_init) {
      hf__hashmap__free(&parser.keyword_map, NULL);
    }

    // free(interpreter.call_stack);
    // free(interpreter.stack);
    hf__interpreter__free(&interpreter);

    if (arguments.output_file) {
      close(fd);
    }

    if (err) {
      return 1;
    } else if (!interpreter.is_running) {
      return interpreter.exit_code;
    }
  }

  return 0;
}