#define _DEFAULT_SOURCE

#include "cst_agent.h"
#include "os_compat.h"

#include <errno.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#ifdef _WIN32
#include <io.h>
#else
#include <unistd.h>
#endif

/* Config dir via os_compat: ~/.config/cst-agent or %APPDATA%\cst-agent */

static int credentials_path(char *out, size_t n) {
  char dir[OS_PATH_MAX];
  if (os_config_dir(dir, sizeof(dir)) != 0)
    return -1;
  return os_path_join(out, n, dir, "credentials");
}

int cst_creds_load_api_key(char *out, size_t out_sz) {
  if (!out || out_sz < 2)
    return -1;
  out[0] = 0;
  char path[OS_PATH_MAX];
  if (credentials_path(path, sizeof(path)) != 0)
    return -1;
  FILE *fp = fopen(path, "r");
  if (!fp)
    return -1;
  char line[1024];
  while (fgets(line, sizeof(line), fp)) {
    if (strncmp(line, "api_key=", 8) != 0)
      continue;
    char *v = line + 8;
    size_t len = strlen(v);
    while (len > 0 && (v[len - 1] == '\n' || v[len - 1] == '\r'))
      v[--len] = 0;
    if (len == 0 || len + 1 > out_sz) {
      fclose(fp);
      return -1;
    }
    memcpy(out, v, len + 1);
    fclose(fp);
    return 0;
  }
  fclose(fp);
  return -1;
}

int cst_creds_save_api_key(const char *key) {
  if (!key || !key[0])
    return -1;
  char dir[OS_PATH_MAX], path[OS_PATH_MAX];
  if (os_config_dir(dir, sizeof(dir)) != 0)
    return -1;
  if (os_mkdir(dir, 0700) != 0)
    return -1;
  if (credentials_path(path, sizeof(path)) != 0)
    return -1;
  FILE *fp = fopen(path, "w");
  if (!fp)
    return -1;
  fprintf(fp, "api_key=%s\n", key);
  fprintf(fp, "api_base=https://api.minimax.cn/v1\n");
  fprintf(fp, "model=MiniMax-M2.7\n");
  fclose(fp);
  (void)os_chmod_private(path);
  return 0;
}

/* Zenity on Unix; stdin prompt elsewhere / when zenity missing. */
int cst_creds_prompt_api_key(char *out, size_t out_sz) {
  if (!out || out_sz < 2)
    return -1;
  out[0] = 0;

#ifndef _WIN32
  FILE *fp = popen(
      "zenity --password --title='CST-Agent / MiniMax' "
      "--text='请输入 MiniMax API Key（将保存到配置目录 credentials）' "
      "2>/dev/null",
      "r");
  if (fp) {
    if (fgets(out, (int)out_sz, fp)) {
      int st = pclose(fp);
      size_t len = strlen(out);
      while (len > 0 && (out[len - 1] == '\n' || out[len - 1] == '\r'))
        out[--len] = 0;
      if (st == 0 && len > 0)
        return 0;
    } else {
      pclose(fp);
    }
    out[0] = 0;
  }
#endif

  /* Fallback: console prompt (headless / Windows / no zenity). */
  fprintf(stderr, "CST-Agent: enter MiniMax API Key (saved to config dir): ");
  fflush(stderr);
  if (!fgets(out, (int)out_sz, stdin)) {
    out[0] = 0;
    return -1;
  }
  size_t len = strlen(out);
  while (len > 0 && (out[len - 1] == '\n' || out[len - 1] == '\r'))
    out[--len] = 0;
  if (len == 0) {
    out[0] = 0;
    return -1;
  }
  return 0;
}

int cst_creds_ensure_api_key(char *out, size_t out_sz) {
  const char *env = getenv("CST_API_KEY");
  if (!env || !env[0])
    env = getenv("MINIMAX_API_KEY");
  if (!env || !env[0])
    env = getenv("OPENAI_API_KEY");
  if (env && env[0]) {
    snprintf(out, out_sz, "%s", env);
    return 0;
  }
  if (cst_creds_load_api_key(out, out_sz) == 0 && out[0])
    return 0;
  if (cst_creds_prompt_api_key(out, out_sz) != 0)
    return -1;
  if (cst_creds_save_api_key(out) != 0)
    fprintf(stderr, "warning: failed to save credentials file\n");
  else
    fprintf(stderr, "saved API key to config directory\n");
  return 0;
}