#include "../libs/cjson/cJSON.h"
#include <fcntl.h>
#include <stdbool.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/ioctl.h>
#include <sys/wait.h>
#include <termios.h>
#include <unistd.h>

int lsp_stdin_fd = -1;
int lsp_stdout_fd = -1;
int cols;

void start_lsp(const char *cmd, char *const argv[]) {
  int in_pipe[2];
  int out_pipe[2];
  if (pipe(in_pipe) == -1 || pipe(out_pipe) == -1) {
    perror("pipe");
    exit(1);
  }
  pid_t pid = fork();
  if (pid == -1) {
    perror("fork");
    exit(1);
  }
  if (pid == 0) {
    dup2(in_pipe[0], STDIN_FILENO);
    dup2(out_pipe[1], STDOUT_FILENO);
    int devnull = open("/dev/null", O_WRONLY);
    if (devnull != -1) {
      dup2(devnull, STDERR_FILENO);
      close(devnull);
    }
    close(in_pipe[1]);
    close(out_pipe[0]);
    execvp(cmd, argv);
    perror("execvp");
    _exit(1);
  }
  close(in_pipe[0]);
  close(out_pipe[1]);
  lsp_stdin_fd = in_pipe[1];
  lsp_stdout_fd = out_pipe[0];
}

void lsp_send(cJSON *msg) {
  char *dump = cJSON_PrintUnformatted(msg);
  int len = strlen(dump);
  dprintf(lsp_stdin_fd, "Content-Length: %d\r\n\r\n%s", len, dump);
  free(dump);
}

cJSON *lsp_recv() {
  char header[256];
  int content_length = 0;
  char c;
  int pos = 0;
  int newlines = 0;
  while (read(lsp_stdout_fd, &c, 1) == 1) {
    header[pos++] = c;
    if (pos >= sizeof(header) - 1)
      break;
    if (c == '\n') {
      header[pos] = '\0';
      if (strncmp(header, "Content-Length:", 15) == 0) {
        content_length = atoi(header + 15);
      }
      if (strcmp(header, "\r\n") == 0)
        break;
      pos = 0;
    }
  }
  if (content_length <= 0)
    return NULL;
  char *buf = malloc(content_length + 1);
  if (!buf)
    return NULL;
  int got = 0;
  while (got < content_length) {
    int n = read(lsp_stdout_fd, buf + got, content_length - got);
    if (n <= 0)
      break;
    got += n;
  }
  buf[got] = '\0';
  cJSON *msg = cJSON_Parse(buf);
  free(buf);
  return msg;
}

cJSON *make_fold_request(int id, const char *uri) {
  cJSON *root = cJSON_CreateObject();
  cJSON_AddStringToObject(root, "jsonrpc", "2.0");
  cJSON_AddNumberToObject(root, "id", id);
  cJSON_AddStringToObject(root, "method", "textDocument/foldingRange");
  cJSON *params = cJSON_CreateObject();
  cJSON *doc = cJSON_CreateObject();
  cJSON_AddStringToObject(doc, "uri", uri);
  cJSON_AddItemToObject(params, "textDocument", doc);
  cJSON_AddItemToObject(root, "params", params);
  return root;
}

cJSON *make_hover_request(int id, const char *uri) {
  cJSON *root = cJSON_CreateObject();
  cJSON_AddStringToObject(root, "jsonrpc", "2.0");
  cJSON_AddNumberToObject(root, "id", id);
  cJSON_AddStringToObject(root, "method", "textDocument/completion");
  cJSON *params = cJSON_CreateObject();
  cJSON *doc = cJSON_CreateObject();
  cJSON_AddStringToObject(doc, "uri", uri);
  cJSON_AddItemToObject(params, "textDocument", doc);
  cJSON *pos = cJSON_CreateObject();
  cJSON_AddNumberToObject(pos, "line", 15);
  cJSON_AddNumberToObject(pos, "character", 6);
  cJSON_AddItemToObject(params, "position", pos);
  cJSON_AddItemToObject(root, "params", params);
  return root;
}

cJSON *make_document_symbol_request(int id, const char *uri) {
  cJSON *root = cJSON_CreateObject();
  cJSON_AddStringToObject(root, "jsonrpc", "2.0");
  cJSON_AddNumberToObject(root, "id", id);
  cJSON_AddStringToObject(root, "method", "textDocument/documentSymbol");

  cJSON *params = cJSON_CreateObject();
  cJSON *textDocument = cJSON_CreateObject();
  cJSON_AddStringToObject(textDocument, "uri", uri);
  cJSON_AddItemToObject(params, "textDocument", textDocument);

  cJSON_AddItemToObject(root, "params", params);

  return root;
}

cJSON *make_features_request(int id, const char *root_uri) {
  cJSON *root = cJSON_CreateObject();
  cJSON_AddStringToObject(root, "jsonrpc", "2.0");
  cJSON_AddNumberToObject(root, "id", id);
  cJSON_AddStringToObject(root, "method", "initialize");
  cJSON *params = cJSON_CreateObject();
  cJSON_AddStringToObject(params, "processId", "0");
  cJSON_AddStringToObject(params, "rootUri", root_uri);
  cJSON *capabilities = cJSON_CreateObject();
  cJSON_AddItemToObject(params, "capabilities", capabilities);
  cJSON_AddItemToObject(root, "params", params);
  return root;
}

cJSON *make_folder_init_request(int id, const char *root_uri) {
  cJSON *init = cJSON_CreateObject();
  cJSON_AddStringToObject(init, "jsonrpc", "2.0");
  cJSON_AddNumberToObject(init, "id", id);
  cJSON_AddStringToObject(init, "method", "initialize");

  cJSON *params = cJSON_CreateObject();
  cJSON_AddStringToObject(params, "rootUri", root_uri);

  // capabilities
  cJSON *capabilities = cJSON_CreateObject();
  cJSON *textDocument = cJSON_CreateObject();
  cJSON *diagnosticProvider = cJSON_CreateObject();
  // Enable diagnostics
  cJSON_AddBoolToObject(diagnosticProvider, "interFileDependencies", false);
  cJSON_AddBoolToObject(diagnosticProvider, "workspaceDiagnostics", false);
  cJSON_AddItemToObject(textDocument, "diagnosticProvider", diagnosticProvider);
  cJSON_AddItemToObject(capabilities, "textDocument", textDocument);

  cJSON_AddItemToObject(params, "capabilities", capabilities);
  cJSON_AddItemToObject(init, "params", params);

  return init;
}

cJSON *make_initialized_request(void) {
  cJSON *msg = cJSON_CreateObject();
  cJSON_AddStringToObject(msg, "jsonrpc", "2.0");
  cJSON_AddStringToObject(msg, "method", "initialized");
  cJSON *params = cJSON_CreateObject();
  cJSON_AddItemToObject(msg, "params", params);
  return msg;
}

cJSON *make_change_file_request(int id, const char *uri) {
  cJSON *root = cJSON_CreateObject();
  cJSON_AddStringToObject(root, "jsonrpc", "2.0");
  cJSON_AddStringToObject(root, "method", "textDocument/didChange");
  cJSON *params = cJSON_CreateObject();
  cJSON *doc = cJSON_CreateObject();
  cJSON_AddStringToObject(doc, "uri", uri);
  cJSON_AddNumberToObject(doc, "version", 2);
  cJSON_AddItemToObject(params, "textDocument", doc);
  cJSON *changes = cJSON_CreateArray();
  cJSON *change = cJSON_CreateObject();
  cJSON *range = cJSON_CreateObject();
  cJSON *start = cJSON_CreateObject();
  cJSON_AddNumberToObject(start, "line", 0);
  cJSON_AddNumberToObject(start, "character", 0);
  cJSON *end = cJSON_CreateObject();
  cJSON_AddNumberToObject(end, "line", 0);
  cJSON_AddNumberToObject(end, "character", 0);
  cJSON_AddItemToObject(range, "start", start);
  cJSON_AddItemToObject(range, "end", end);
  cJSON_AddItemToObject(change, "range", range);
  cJSON_AddStringToObject(change, "text", "");
  cJSON_AddItemToArray(changes, change);
  cJSON_AddItemToObject(params, "contentChanges", changes);
  cJSON_AddItemToObject(root, "params", params);
  return root;
}

cJSON *make_open_file_request(const char *uri, const char *languageId,
                              const char *text, int version) {
  cJSON *msg = cJSON_CreateObject();
  cJSON_AddStringToObject(msg, "jsonrpc", "2.0");
  cJSON_AddStringToObject(msg, "method", "textDocument/didOpen");

  cJSON *params = cJSON_CreateObject();
  cJSON *doc = cJSON_CreateObject();

  cJSON_AddStringToObject(doc, "uri", uri);
  cJSON_AddStringToObject(doc, "languageId", languageId);
  cJSON_AddNumberToObject(doc, "version", version);
  cJSON_AddStringToObject(doc, "text", text);

  cJSON_AddItemToObject(params, "textDocument", doc);
  cJSON_AddItemToObject(msg, "params", params);

  return msg;
}

int get_key(void) {
  struct termios oldt, newt;
  int ch;
  tcgetattr(STDIN_FILENO, &oldt);
  newt = oldt;
  newt.c_lflag &= ~(ICANON | ECHO);
  tcsetattr(STDIN_FILENO, TCSANOW, &newt);
  ch = getchar();
  tcsetattr(STDIN_FILENO, TCSANOW, &oldt);
  struct winsize ws;
  ioctl(STDOUT_FILENO, TIOCGWINSZ, &ws);
  cols = ws.ws_col;
  return ch;
}

char *read_file(const char *path) {
  FILE *f = fopen(path, "rb");
  if (!f)
    return NULL;

  // seek to end to get size
  if (fseek(f, 0, SEEK_END) != 0) {
    fclose(f);
    return NULL;
  }
  long size = ftell(f);
  if (size < 0) {
    fclose(f);
    return NULL;
  }
  rewind(f);

  char *buf = malloc(size + 1);
  if (!buf) {
    fclose(f);
    return NULL;
  }

  size_t read_size = fread(buf, 1, size, f);
  buf[read_size] = '\0'; // null terminate
  fclose(f);

  return buf;
}

void print_wrapped(const char *text) {
  struct winsize ws;
  ioctl(STDOUT_FILENO, TIOCGWINSZ, &ws);
  int cols = ws.ws_col > 0 ? ws.ws_col : 80; // fallback to 80 if unknown

  int col = 0;
  for (size_t i = 0; text[i]; i++) {
    putchar(text[i]);
    col++;

    if (text[i] == '\n') {
      col = 0; // reset column on explicit newline
    } else if (col >= cols) {
      putchar('\n');
      col = 0;
    }
  }
}

int main() {
  char *argv[] = {"clangd", NULL};
  start_lsp("clangd", argv);
  cJSON *init =
      make_folder_init_request(1, "file:///home/syed/main/cubit/tests/");
  lsp_send(init);
  cJSON_Delete(init);
  cJSON *initialized = make_initialized_request();
  lsp_send(initialized);
  cJSON_Delete(initialized);
  char *text = read_file("/home/syed/main/cubit/tests/test.c");
  printf("%s\n", text);
  cJSON *req = make_open_file_request(
      "file:///home/syed/main/cubit/tests/test.c", "c", text, 1);
  lsp_send(req);
  cJSON_Delete(req);
  free(text);
  // cJSON *doc_sym_req = make_document_symbol_request(
  //     2, "file:///home/syed/main/cubit/tests/test.c");
  // lsp_send(doc_sym_req);
  // cJSON_Delete(doc_sym_req);
  usleep(1000000);
  int next_id = 3;
  while (1) {
    printf("Press 'f' to request fold ranges, 'q' to quit: ");
    fflush(stdout);
    int key = get_key();
    printf("\n");
    if (key == 'q')
      break;
    if (key == 'f') {
      cJSON *req = make_fold_request(
          next_id++, "file:///home/syed/main/cubit/tests/test.c");
      lsp_send(req);
      cJSON_Delete(req);
    }
    if (key == 'i') {
      cJSON *req = make_features_request(next_id++,
                                         "file:///home/syed/main/cubit/tests/");
      lsp_send(req);
      cJSON_Delete(req);
    }
    if (key == 'h') {
      cJSON *req = make_hover_request(
          next_id++, "file:///home/syed/main/cubit/tests/test.c");
      lsp_send(req);
      cJSON_Delete(req);
    }
    if (key == 'c') {
      cJSON *req = make_change_file_request(
          next_id++, "file:///home/syed/main/cubit/tests/test.c");
      lsp_send(req);
      cJSON_Delete(req);
    }
    cJSON *resp;
    if ((resp = lsp_recv()) == NULL)
      continue;
    char *dump = cJSON_PrintUnformatted(resp);
    cJSON *id = cJSON_GetObjectItem(resp, "id");
    // if (id != NULL && id->valueint == 40) {
    //   cJSON *result = cJSON_GetObjectItem(resp, "result");
    //   cJSON *contents = cJSON_GetObjectItem(result, "contents");
    //   cJSON *value = cJSON_GetObjectItem(contents, "value");
    //   if (value && value->type == cJSON_String)
    //     printf("%s\n", value->valuestring);
    // }
    print_wrapped(dump);
    free(dump);
    cJSON_Delete(resp);
  }

  return 0;
}