#include "interp.h"
#include "arena_alloc.h"
#include "context.h"
#include "edit.h"
#include "parser.h"
#include <debugconsole.h>
#include <desc.h>
#include <filereader.h>
#include <filewriter.h>
#include <fs_types.h>
#include <kb.h>
#include <malloc.h>
#include <mprintf.h>
#include <path.h>
#include <printf.h>
#include <proc_info.h>
#include <process.h>
#include <stall.h>
#include <stddef.h>
#include <str_status.h>
#include <strconv.h>
#include <streams.h>
#include <string.h>
#include <system.h>
#include <tcursor.h>
#include <terminal.h>
#include <tscreen.h>
#include <write_file.h>

static bool run = true;

struct posvar posvars[POSVAR_MAX];
int posvar_count = 0;

bool interp_is_running(void) { return run; }

void interp_shutdown(void) { run = false; }

static void human_size(double size, double* out, char** str) {
  static char* units[] = {"B", "KiB", "MiB", "GiB", "TiB", "PiB"};

  size_t i = 0;
  while (size >= 1024.0 && i < (sizeof(units) / sizeof(units[0])) - 1) {
    size /= 1024.0;
    i++;
  }

  *out = size;
  *str = units[i];
}

static void echo(struct context* context, char** strings, size_t strings_count) {
  for (size_t i = 0; i < strings_count; i++) {
    cprintf(context, "%s", strings[i]);

    if (i != strings_count - 1)
      cprintf(context, " ");
  }
}

static void mkfile(struct context* context, char** file_paths, size_t files_count) {
  char volume[VOLUME_MAX];
  const char* path;
  int ret;

  for (size_t i = 0; i < files_count; i++) {
    const char* file_path = file_paths[i];

    if (!path_parse(file_path, volume, &path)) {
      cprintf(context, "ERROR bad path '%s'\n", file_path);
      continue;
    }

    if ((ret = volume_open(volume)) < 0) {
      cprintf(context, "ERROR could not open volume '%s': %s\n", volume, str_status[-ret]);
      continue;
    }

    if ((ret = create_file(path)) < 0) {
      cprintf(context, "ERROR could not create file '%s': %s\n", file_path, str_status[-ret]);
    }

    volume_close();
  }
}

static void terminfo(struct context* context) {
  size_t cols = 0, rows = 0;
  terminal_dimensions(&cols, &rows);
  cprintf(context, "%zu x %zu\n", cols, rows);
}

static void procinfo(struct context* context) {
  struct proc_info* infos = malloc(sizeof(struct proc_info) * 1024);
  memset(infos, 0, sizeof(struct proc_info) * 1024);

  int count = get_proc_info(infos, 1024);

  const char* proc_states[] = {"ready", "suspended", "partial"};

  for (int i = 0; i < count; i++) {
    struct proc_info* info = &infos[i];
    cprintf(context, "%-40s CPU=%-2d EXEC_PID=%-4d FLAGS=%08x PGID=%-4d PID=%-4d STATE=%-10s\n",
            info->name, info->cpu, info->exec_pid, info->flags, info->pgid, info->pid,
            proc_states[info->state]);
  }

  free(infos);
}

static void mkdir(struct context* context, char** dir_paths, size_t dirs_count) {
  char volume[VOLUME_MAX];
  const char* path;
  int ret;

  for (size_t i = 0; i < dirs_count; i++) {
    const char* dir_path = dir_paths[i];

    if (!path_parse(dir_path, volume, &path)) {
      cprintf(context, "ERROR bad path '%s'\n", dir_path);
      continue;
    }

    if ((ret = volume_open(volume)) < 0) {
      cprintf(context, "ERROR could not open volume '%s': %s\n", volume, str_status[-ret]);
      continue;
    }

    create_dir(path);

    volume_close();
  }
}

static void rm(struct context* context, char** paths, size_t count) {
  char volume[VOLUME_MAX];
  const char* path;
  int ret;

  for (size_t i = 0; i < count; i++) {
    const char* path1 = paths[i];

    if (!path_parse(path1, volume, &path)) {
      cprintf(context, "ERROR bad path '%s'\n", path1);
      continue;
    }

    if ((ret = volume_open(volume)) < 0) {
      cprintf(context, "ERROR could not open volume '%s': %s\n", volume, str_status[-ret]);
      continue;
    }

    remove(path);

    volume_close();
  }
}

static void cat(struct context* context, char** file_paths, size_t files_count) {
  char volume[VOLUME_MAX];
  const char* path;
  int ret;

  for (size_t i = 0; i < files_count; i++) {
    const char* file_path = file_paths[i];

    if (!path_parse(file_path, volume, &path)) {
      cprintf(context, "ERROR bad path '%s'\n", file_path);
      continue;
    }

    struct filereader fr;
    if ((ret = filereader_init(&fr, volume, path)) < 0) {
      cprintf(context, "ERROR could not initialize filereader for '%s:%s'\n", volume, path);
      return;
    }

    size_t chunk_size = 1024;
    char* buffer = arena_malloc(&arena, chunk_size);

    size_t chunks = fr.file_size / chunk_size;
    size_t rem = fr.file_size % chunk_size;

    for (size_t chunk = 0; chunk < chunks; chunk++) {
      if ((ret = filereader_read(&fr, (uint8_t*)buffer, chunk_size)) < 0) {
        filereader_fini(&fr);
        cprintf(context, "ERROR filereader failed to read from '%s:%s'\n", volume, path);
        return;
      }

      stream_write(process_get_pgid(), STREAM_OUT, buffer, chunk_size);
    }

    if (rem > 0) {
      if ((ret = filereader_read(&fr, (uint8_t*)buffer, rem)) < 0) {
        filereader_fini(&fr);
        cprintf(context, "ERROR filereader failed to read from '%s:%s'\n", volume, path);
        return;
      }

      stream_write(process_get_pgid(), STREAM_OUT, buffer, rem);
    }

    filereader_fini(&fr);
  }
}

static void copy(struct context* context, const char* path_a, const char* path_b) {
  char volume_a[VOLUME_MAX], volume_b[VOLUME_MAX];
  const char *path_a1, *path_b1;
  int ret;

  if (!path_parse(path_a, volume_a, &path_a1)) {
    cprintf(context, "ERROR bad path '%s'\n", path_a);
    return;
  }

  if (!(path_parse(path_b, volume_b, &path_b1))) {
    cprintf(context, "ERROR bad path '%s'\n", path_b);
    return;
  }

  struct desc desc;

  if ((ret = volume_open(volume_a)) < 0) {
    cprintf(context, "ERROR could not open volume '%s'\n", volume_a);
    return;
  }

  if ((ret = describe(path_a1, &desc)) < 0 || desc.type != FS_FILE) {
    volume_close();
    cprintf(context, "ERROR invalid source '%s:%s'\n", volume_a, path_a1);
    return;
  }

  size_t file_size = desc.size;

  volume_close();

  if ((ret = volume_open(volume_b)) < 0) {
    cprintf(context, "ERROR could not open volume '%s'\n", volume_b);
    return;
  }

  create_file(path_b1);

  volume_close();

  size_t chunk_size = 10 * 1024 * 1024;
  char* buffer = malloc(chunk_size);

  if (buffer == NULL) {
    return;
  }

  size_t cursor = 0;

  while (cursor < file_size) {
    size_t to_read = chunk_size;

    if (file_size - cursor < to_read)
      to_read = file_size - cursor;

    if ((ret = volume_open(volume_a)) < 0) {
      cprintf(context, "ERROR could not open volume '%s'\n", volume_a);
      break;
    }

    if ((ret = read_file(path_a1, cursor, (uint8_t*)buffer, to_read)) < 0) {
      volume_close();
      cprintf(context, "ERROR read '%s:%s'\n", volume_a, path_a1);
      break;
    }

    volume_close();

    if ((ret = volume_open(volume_b)) < 0) {
      cprintf(context, "ERROR could not open volume '%s'\n", volume_b);
      break;
    }

    uint32_t wf_flags = (cursor == 0) ? WF_TRUNCATE : 0;

    if ((ret = write_file(path_b1, cursor, (uint8_t*)buffer, to_read, wf_flags)) < 0) {
      volume_close();
      cprintf(context, "ERROR write '%s:%s'\n", volume_b, path_b1);
      break;
    }

    volume_close();

    cursor += to_read;
  }

  free(buffer);
}

static void ls(struct context* context, const char* path_string) {
  struct desc desc;
  char volume[VOLUME_MAX];
  const char* path;
  int ret;
  struct dir_entry entry;

  if (!path_parse(path_string, volume, &path)) {
    cprintf(context, "ERROR bad path '%s'\n", path_string);
    return;
  }

  if ((ret = volume_open(volume)) < 0) {
    cprintf(context, "ERROR could not open volume '%s': %s\n", volume, str_status[-ret]);
    return;
  }

  describe(path, &desc);

  if (desc.type != FS_DIR) {
    cprintf(context, "ERROR '%s' is not a directory\n", path_string);
    volume_close();
    return;
  }

  size_t entries = desc.size;
  cprintf(context, "total entries: %zu\n", entries);
  cprintf(context, "\n");

  for (size_t entry_num = 0; entry_num < entries; entry_num++) {
    memset(&desc, 0, sizeof(desc));
    memset(&entry, 0, sizeof(entry));

    read_dir_entry(path, &entry, entry_num);
    describe(entry.path, &desc);

    char* hs_string;
    double hs;
    human_size((double)desc.size, &hs, &hs_string);

    char size_buf[64];
    snprintf(size_buf, sizeof(size_buf), "%.2f %s", hs, hs_string);

    char type = (desc.type == FS_DIR ? 'D' : 'F');

    cprintf(context, "%c %-50s %-10s\n", type, path_basename(entry.path), size_buf);
  }

  volume_close();
}

static void edit(struct context* context, const char* path_string) {
  struct desc desc;
  char volume[VOLUME_MAX];
  const char* path;
  int ret;

  if (!path_parse(path_string, volume, &path)) {
    cprintf(context, "ERROR bad path '%s'\n", path_string);
    return;
  }

  if ((ret = volume_open(volume)) < 0) {
    cprintf(context, "ERROR could not open volume '%s': %s\n", volume, str_status[-ret]);
    return;
  }

  if ((ret = describe(path, &desc)) < 0) {
    cprintf(context, "ERROR could not describe '%s': %s\n", path, str_status[-ret]);
    volume_close();
    return;
  }

  char* str = malloc(desc.size + 1);

  if (str == NULL) {
    volume_close();
    return;
  }

  memset(str, 0, desc.size);

  if ((ret = read_file(path, 0, (uint8_t*)str, desc.size)) < 0) {
    free(str);
    volume_close();
    return;
  }

  volume_close();

  edit_start(volume, path, str, desc.size);
}

static void quit1(struct context* context) {
  cprintf(context, "Goodbye!\n");
  interp_shutdown();
}

static void cls(struct context* context) { cprintf(context, ANSIQ_CUR_HOME ANSIQ_SCR_CLR_ALL); }

static void mkvol(struct context* context, const char* volume, const char* str_fs_type,
                  const char* device) {
  int fs_type;

  if (strcmp(str_fs_type, "tar") == 0) {
    fs_type = FS_TARFS;
  } else if (strcmp(str_fs_type, "fat16") == 0) {
    fs_type = FS_FAT16;
  } else if (strcmp(str_fs_type, "fat32") == 0) {
    fs_type = FS_FAT32;
  } else if (strcmp(str_fs_type, "iso9660") == 0) {
    fs_type = FS_ISO9660;
  } else {
    cprintf(context, "ERROR Unknown filesystem '%s'\n", str_fs_type);
    return;
  }

  int ret = create_volume(volume, fs_type, device);

  if (ret < 0)
    cprintf(context, "ERROR Could not create volume: %s\n", str_status[-ret]);
}

static void stall(uint64_t ms) { stall_ms(ms); }

static void help(struct context* context) {
  cprintf(context, "Available commands:\n");
  cprintf(context, "help\n");
  cprintf(context, "echo         <word1> <word2> <word3> ...\n");
  cprintf(context, "cat          <file path>\n");
  cprintf(context, "ls           <directory path>\n");
  cprintf(context, "mkfile       <file path>\n");
  cprintf(context, "mkdir        <directory path>\n");
  cprintf(context, "rm           <path>\n");
  cprintf(context, "edit         <path>\n");
  cprintf(context, "terminfo\n");
  cprintf(context, "cls\n");
  cprintf(context, "mkvol        <volume> <filesystem> <device>\n");
  cprintf(context, "procinfo\n");
  cprintf(context, "quit\n");
  cprintf(context, "stall        <milliseconds>\n");
  cprintf(context, "copy         <path A> <path B>\n");
}

struct cmd_write_proc_ctx {
  int pgid;
  int cancel_pid;
};

static void cmd_collect_proc(void* arg) {
  int pgid = (int)(uintptr_t)arg;

  char recv[1024];
  int n;
  for (;;) {
    if ((n = stream_read(pgid, STREAM_OUT, (void*)recv, sizeof(recv) - 1)) > 0)
      stream_write(process_get_pgid(), STREAM_OUT, (void*)recv, n);
    else
      sched();
  }
}

static void cmd_write_proc(void* arg) {
  struct cmd_write_proc_ctx* ctx = arg;

  uint8_t ch = 0;
  for (;;) {
    if (stream_read(process_get_pgid(), STREAM_IN, &ch, 1) > 0) {
      if (ch == KB_CTRL('C')) {
        kill(ctx->cancel_pid);
        return;
      }

      stream_write(ctx->pgid, STREAM_IN, &ch, 1);
    } else {
      sched();
    }
  }
}

static void execute_cmd(struct ast_cmd* cmd, struct context* context, bool run_bg) {
  if (strcmp(cmd->name, "echo") == 0) {
    echo(context, cmd->args, cmd->arg_count);
  } else if (strcmp(cmd->name, "help") == 0) {
    help(context);
  } else if (strcmp(cmd->name, "cat") == 0) {
    cat(context, cmd->args, cmd->arg_count);
  } else if (strcmp(cmd->name, "ls") == 0) {
    if (cmd->arg_count == 1)
      ls(context, cmd->args[0]);
    else
      cprintf(context, "ERROR No directory path provided\n");
  } else if (strcmp(cmd->name, "quit") == 0) {
    quit1(context);
  } else if (strcmp(cmd->name, "mkfile") == 0) {
    mkfile(context, cmd->args, cmd->arg_count);
  } else if (strcmp(cmd->name, "mkdir") == 0) {
    mkdir(context, cmd->args, cmd->arg_count);
  } else if (strcmp(cmd->name, "rm") == 0) {
    rm(context, cmd->args, cmd->arg_count);
  } else if (strcmp(cmd->name, "edit") == 0) {
    if (cmd->arg_count == 1)
      edit(context, cmd->args[0]);
    else
      cprintf(context, "ERROR No file path provided\n");
  } else if (strcmp(cmd->name, "terminfo") == 0) {
    terminfo(context);
  } else if (strcmp(cmd->name, "cls") == 0) {
    cls(context);
  } else if (strcmp(cmd->name, "mkvol") == 0) {
    if (cmd->arg_count == 3)
      mkvol(context, cmd->args[0], cmd->args[1], cmd->args[2]);
    else
      cprintf(context, "ERROR No volume key, filesystem type or device key provided\n");
  } else if (strcmp(cmd->name, "procinfo") == 0) {
    procinfo(context);
  } else if (strcmp(cmd->name, "stall") == 0) {
    if (cmd->arg_count == 1) {
      uint64_t ms = str_to_uint64(cmd->args[0]);
      stall(ms);
    } else {
      cprintf(context, "ERROR stall requires a timeout argument\n");
    }
  } else if (strcmp(cmd->name, "copy") == 0) {
    if (cmd->arg_count == 2)
      copy(context, cmd->args[0], cmd->args[1]);
    else
      cprintf(context, "ERROR copy requires source and destination\n");
  } else {
    char volume[VOLUME_MAX];
    const char* path;

    if (!(path_parse(cmd->name, volume, &path))) {
      cprintf(context, "ERROR bad path '%s'\n", cmd->name);
      return;
    }

    int pid = exec_partial(volume, path);

    if (pid < 0) {
      cprintf(context, "ERROR could not run '%s': %s\n", cmd->name, str_status[-pid]);
      return;
    }

    int pgid = get_procgroup(pid);

    int i = 0;
    while (i < cmd->arg_count) {
      char* arg = cmd->args[i];
      char *key, *value;

      if (arg[0] == '-') {
        key = &arg[1];

        if (i < cmd->arg_count - 1) {
          value = cmd->args[++i];
        } else {
          value = "yes";
        }

        env_set(pgid, key, value, strlen(value) + 1);
      }

      i++;
    }

    if (run_bg) {
      exec_partial_fini(pid);

      cprintf(context, "started background process: PID %d\n", pid);
    } else {
      struct cmd_write_proc_ctx wpctx = {.pgid = pgid, .cancel_pid = pid};

      struct process_data* write_pdata = process_spawn(&cmd_write_proc, (void*)&wpctx);
      struct process_data* collect_pdata = process_spawn(&cmd_collect_proc, (void*)(uintptr_t)pgid);

      exec_partial_fini(pid);
      wait_for_pid(pid);

      kill(write_pdata->pid);
      process_data_free(write_pdata);
      kill(collect_pdata->pid);
      process_data_free(collect_pdata);
    }
  }
}

static void execute_redir(struct ast_redir* redir, struct context* context) {
  char volume[VOLUME_MAX];
  const char* path;
  int ret;

  if (!(path_parse(redir->file_path, volume, &path))) {
    cprintf(context, "ERROR bad path '%s'\n", redir->file_path);
    return;
  }

  uint32_t fw_flags = FW_CREATE_FILE | FW_TRUNCATE;

  struct filewriter fw;
  if ((ret = filewriter_init(&fw, volume, path, fw_flags)) < 0) {
    cprintf(context, "ERROR could not initialize filewriter for '%s:%s'\n", volume, path);
    return;
  }

  if (context->strbuf.count == 0) {
    filewriter_fini(&fw);
    return;
  }

  size_t chunk_size = 1024;
  size_t chunks = (context->strbuf.count - 1) / chunk_size;
  size_t rem = (context->strbuf.count - 1) % chunk_size;

  for (size_t chunk = 0; chunk < chunks; chunk++) {
    if ((ret = filewriter_write(&fw, (uint8_t*)&context->strbuf.items[chunk * chunk_size],
                                chunk_size)) < 0) {
      filewriter_fini(&fw);
      cprintf(context, "ERROR filewriter failed to write to '%s:%s'\n", volume, path);
      return;
    }
  }

  if (rem > 0) {
    if ((ret = filewriter_write(&fw, (uint8_t*)&context->strbuf.items[chunks * chunk_size], rem)) <
        0) {
      filewriter_fini(&fw);
      cprintf(context, "ERROR filewriter failed to write to '%s:%s'\n", volume, path);
      return;
    }
  }

  filewriter_fini(&fw);
}

void execute(struct ast_node* root, struct context* context, bool run_bg) {
  struct context subcontext;
  memset(&subcontext, 0, sizeof(subcontext));

  switch (root->class) {
  case AST_NODE_CLASS_CMD:
    execute_cmd(&root->u.cmd, context, run_bg);
    break;
  case AST_NODE_CLASS_SUBSHELL:
    execute(root->u.subshell.inner, &subcontext, run_bg);
    break;
  case AST_NODE_CLASS_SEQ:
    execute(root->u.seq.left, context, run_bg);
    execute(root->u.seq.right, context, run_bg);
    break;
  case AST_NODE_CLASS_REDIR:
    execute(root->u.redir.source, &subcontext, run_bg);
    execute_redir(&root->u.redir, &subcontext);
    break;
  case AST_NODE_CLASS_RUN_BG:
    execute(root->u.run_bg.expr, context, true);
    break;
  }
}