/* The tools that answer "make me a document", "read this PDF", "get that URL"
 * and "where are we": md_to_html, read_pdf, download, session_search and
 * device_info.
 *
 * Nothing here touches the network: download is checked on the arguments and
 * the file-name rules it applies before any request is made, which is where
 * its mistakes would cost a disk. */
#define _POSIX_C_SOURCE 200809L

#include "cst_agent.h"
#include "cst_tools.h"

#include <stdarg.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/stat.h>
#include <unistd.h>

#include "cst_test_util.h"

static int nfail;

#define EXPECT(cond, msg)                                                      \
  do {                                                                         \
    if (!(cond)) {                                                             \
      fprintf(stderr, "FAIL %s:%d: %s\n", __FILE__, __LINE__, msg);            \
      nfail++;                                                                 \
    }                                                                          \
  } while (0)

static char g_ws[256];

/* name, then key/value pairs, NULL-terminated. */
static ctl_tool_call_t mk(const char *name, ...) {
  ctl_tool_call_t c;
  memset(&c, 0, sizeof(c));
  snprintf(c.id, sizeof(c.id), "t");
  snprintf(c.name, sizeof(c.name), "%s", name);
  va_list ap;
  va_start(ap, name);
  const char *k;
  while ((k = va_arg(ap, const char *)) != NULL) {
    const char *v = va_arg(ap, const char *);
    ctl_arg_t *a = &c.args[c.nargs++];
    snprintf(a->key, sizeof(a->key), "%s", k);
    a->value = (char *)v;
    a->value_len = strlen(v);
  }
  va_end(ap);
  return c;
}

static int run(cst_tool_ctx_t *ctx, ctl_tool_call_t c, cst_tool_result_t *r) {
  memset(r, 0, sizeof(*r));
  cst_tool_run(ctx, &c, r);
  return r->exit_code;
}

static char *rfile(const char *rel) {
  char p[512];
  snprintf(p, sizeof(p), "%s/%s", g_ws, rel);
  FILE *fp = fopen(p, "rb");
  if (!fp)
    return NULL;
  static char buf[262144];
  size_t n = fread(buf, 1, sizeof(buf) - 1, fp);
  buf[n] = 0;
  fclose(fp);
  return buf;
}

static void wfile(const char *rel, const char *s) {
  char p[512];
  snprintf(p, sizeof(p), "%s/%s", g_ws, rel);
  FILE *fp = fopen(p, "wb");
  if (fp) {
    fputs(s, fp);
    fclose(fp);
  }
}

static int exists(const char *rel) {
  char p[512];
  struct stat st;
  snprintf(p, sizeof(p), "%s/%s", g_ws, rel);
  return stat(p, &st) == 0;
}

/* --- md_to_html: one file that stands on its own ------------------------- */
static void test_md_to_html(cst_tool_ctx_t *ctx) {
  cst_tool_result_t r;
  ctl_tool_call_t c =
      mk("md_to_html", "markdown",
         "# Report\n\n- one\n- two\n\n<script>alert(1)</script>\n\n"
         "[x](javascript:alert(2))\n",
         "title", "Report", NULL);
  EXPECT(run(ctx, c, &r) == 0, "markdown renders to a document");
  EXPECT(r.out && strstr(r.out, "Report.html") != NULL,
         "the answer names the file it wrote");
  char *html = rfile("Report.html");
  EXPECT(html != NULL, "and the file is there");
  if (html) {
    EXPECT(strncmp(html, "<!doctype html>", 15) == 0, "it is a whole page");
    EXPECT(strstr(html, "charset=\"utf-8\"") != NULL, "with a charset");
    EXPECT(strstr(html, "<h1>Report</h1>") != NULL, "the heading rendered");
    EXPECT(strstr(html, "<li>one</li>") != NULL, "and the list");
    EXPECT(strstr(html, "<script") == NULL, "no script tag survives");
    EXPECT(strstr(html, "javascript:") == NULL, "no javascript: link survives");
  }
  cst_tool_result_free(&r);

  /* a title that is markup stays text in the <title>, and a title with a
   * path separator in it does not escape the directory */
  c = mk("md_to_html", "markdown", "body\n", "title",
         "a <b> & \"c\" ../d", "out", "hostile.html", NULL);
  EXPECT(run(ctx, c, &r) == 0 && rfile("hostile.html") != NULL,
         "a hostile title still writes where it was told");
  cst_tool_result_free(&r);
  html = rfile("hostile.html");
  EXPECT(html && strstr(html, "<title>a &lt;b&gt; &amp; &quot;c&quot; ../d"
                              "</title>") != NULL,
         "the title is escaped");
  EXPECT(!exists("../d.html"), "and nothing lands outside the workspace");

  /* a .md file, and an output directory */
  char dir[512];
  snprintf(dir, sizeof(dir), "%s/notes", g_ws);
  mkdir(dir, 0755);
  wfile("notes/source.md", "## From a file\n\nbody\n");
  c = mk("md_to_html", "file", "notes/source.md", "out", "notes/", NULL);
  EXPECT(run(ctx, c, &r) == 0, "a workspace file renders");
  EXPECT(r.out && strstr(r.out, "notes/source.html") != NULL,
         "the directory gets the source's name inside it");
  EXPECT(rfile("notes/source.html") != NULL, "the html is there");
  cst_tool_result_free(&r);

  /* the preview the window shows says what will be written */
  char *prev = NULL;
  c = mk("md_to_html", "markdown", "hello", "out", "hello.html", NULL);
  EXPECT(cst_tool_preview(ctx, &c, &prev) == 0 && prev &&
             strstr(prev, "hello.html") != NULL,
         "the preview names the file");
  free(prev);
  c = mk("md_to_html", NULL);
  prev = NULL;
  EXPECT(cst_tool_preview(ctx, &c, &prev) != 0 && prev &&
             strstr(prev, "markdown") != NULL,
         "an empty call is refused in the preview too");
  free(prev);
  EXPECT(run(ctx, c, &r) == 1 && r.out && strstr(r.out, "error") != NULL,
         "and by the tool");
  cst_tool_result_free(&r);
}

/* --- read_pdf: the text layer, and a plain refusal for anything else ---- */
static void test_read_pdf(cst_tool_ctx_t *ctx) {
  cst_tool_result_t r;
  wfile("notreally.pdf", "this is not a pdf at all\n");
  ctl_tool_call_t c = mk("read_pdf", "path", "notreally.pdf", NULL);
  EXPECT(run(ctx, c, &r) == 1 && r.out && strstr(r.out, "PDF") != NULL,
         "a file that is not a PDF is refused");
  cst_tool_result_free(&r);

  c = mk("read_pdf", "path", "missing.pdf", NULL);
  EXPECT(run(ctx, c, &r) == 1 && r.out && strstr(r.out, "error") != NULL,
         "and a missing one");
  cst_tool_result_free(&r);

  c = mk("read_pdf", NULL);
  EXPECT(run(ctx, c, &r) == 1, "a call without a path fails");
  cst_tool_result_free(&r);
}

/* --- download: the file name it picks, before it asks the network ------- */
static void test_download_args(cst_tool_ctx_t *ctx) {
  cst_tool_result_t r;
  ctl_tool_call_t c = mk("download", NULL);
  EXPECT(run(ctx, c, &r) == 1 && r.out && strstr(r.out, "url") != NULL,
         "download without a url fails");
  cst_tool_result_free(&r);

  c = mk("download", "url", "ftp://example.com/x.bin", NULL);
  EXPECT(run(ctx, c, &r) == 1 && r.out && strstr(r.out, "http") != NULL,
         "only http(s) URLs are accepted");
  cst_tool_result_free(&r);

  c = mk("download", "url", "https://example.invalid/x.bin", "path",
         "../escape.bin", NULL);
  EXPECT(run(ctx, c, &r) == 1 && r.out && strstr(r.out, "outside") != NULL,
         "a path that leaves the workspace is refused");
  cst_tool_result_free(&r);
  EXPECT(!exists("escape.bin"), "and nothing was written");
}

/* --- session_search: what was said before ------------------------------- */
static void test_session_search(cst_tool_ctx_t *ctx) {
  EXPECT(cst_agent_store_ensure(g_ws) == 0, "the store exists");
  char path[512];
  EXPECT(cst_agent_store_path_for_id(g_ws, "20260101-120000-fix", path,
                                     sizeof(path)) == 0,
         "a fixture session path");
  cst_session_t *s = cst_session_open(path);
  EXPECT(s != NULL, "its transcript opens");
  cst_message_t m;
  memset(&m, 0, sizeof(m));
  m.role = CST_ROLE_USER;
  m.content = (char *)"how does the Session Store name a session?";
  EXPECT(cst_session_append(s, &m) == 0, "a message goes in");
  memset(&m, 0, sizeof(m));
  m.role = CST_ROLE_ASSISTANT;
  m.content = (char *)"one directory per session, named by a uuid";
  EXPECT(cst_session_append(s, &m) == 0, "and an answer");
  cst_session_close(s);

  cst_tool_result_t r;
  ctl_tool_call_t c = mk("session_search", "query", "uuid", NULL);
  EXPECT(run(ctx, c, &r) == 0, "the search runs");
  EXPECT(r.out && strstr(r.out, "20260101-120000-fix") != NULL &&
             strstr(r.out, "uuid") != NULL,
         "the match names its session and shows the line");
  EXPECT(r.out && strstr(r.out, "#2 assistant") != NULL,
         "with the message number and role");
  cst_tool_result_free(&r);

  c = mk("session_search", "query", "UUID", "ignore_case", "true", NULL);
  EXPECT(run(ctx, c, &r) == 0 && r.out && strstr(r.out, "1 match") != NULL,
         "case-insensitive by default");
  cst_tool_result_free(&r);

  c = mk("session_search", "query", "zzz-nothing-says-this", NULL);
  EXPECT(run(ctx, c, &r) == 0 && r.out && strstr(r.out, "no match") != NULL,
         "a query nothing matches says so (and is not an error)");
  cst_tool_result_free(&r);

  c = mk("session_search", NULL);
  EXPECT(run(ctx, c, &r) == 1, "a query is required");
  cst_tool_result_free(&r);

  /* A store is not read to the end on a whim: a byte budget stops the walk
   * and says so, and it never reports a match it did not get to. */
  {
    char path2[512];
    EXPECT(cst_agent_store_path_for_id(g_ws, "20260101-130000-big", path2,
                                       sizeof(path2)) == 0,
           "a second session path");
    cst_session_t *s2 = cst_session_open(path2);
    EXPECT(s2 != NULL, "its transcript opens");
    if (s2) {
      cst_message_t m2;
      memset(&m2, 0, sizeof(m2));
      m2.role = CST_ROLE_USER;
      m2.content = (char *)"the start of a long one";
      EXPECT(cst_session_append(s2, &m2) == 0, "a first line goes in");
      for (int i = 0; i < 600; i++) {
        memset(&m2, 0, sizeof(m2));
        m2.role = CST_ROLE_ASSISTANT;
        m2.content = (char *)"a line of tool output that says nothing special";
        if (cst_session_append(s2, &m2) != 0)
          break;
      }
      memset(&m2, 0, sizeof(m2));
      m2.role = CST_ROLE_ASSISTANT;
      m2.content = (char *)"the needle is only at the very end";
      EXPECT(cst_session_append(s2, &m2) == 0, "the needle goes in last");
      cst_session_close(s2);
    }
    /* Enough lines that a byte budget is spent before the end is reached. */
    c = mk("session_search", "query", "needle", "max_bytes", "4096", NULL);
    EXPECT(run(ctx, c, &r) == 0 && r.out != NULL, "a bounded search runs");
    EXPECT(r.out && strstr(r.out, "budget stopped the walk") != NULL,
           "the byte budget stops the walk and says so");
    EXPECT(r.out == NULL || strstr(r.out, "the needle is only") == NULL,
           "and it does not report a match it never got to");
    cst_tool_result_free(&r);
    /* The same query without a budget reaches the end and finds it. */
    c = mk("session_search", "query", "needle", NULL);
    EXPECT(run(ctx, c, &r) == 0 && r.out &&
               strstr(r.out, "the needle is only") != NULL,
           "the unbounded search finds it");
    cst_tool_result_free(&r);
  }
}

/* --- device_info: the environment, without a shell ---------------------- */
static void test_device_info(cst_tool_ctx_t *ctx) {
  cst_tool_result_t r;
  ctl_tool_call_t c = mk("device_info", NULL);
  EXPECT(run(ctx, c, &r) == 0, "device_info answers");
  EXPECT(r.out && strstr(r.out, "cst-agent") != NULL, "with the version");
  EXPECT(r.out && strstr(r.out, "system: ") != NULL, "the system it runs on");
  EXPECT(r.out && strstr(r.out, g_ws) != NULL, "the workspace in use");
  cst_tool_result_free(&r);
}

int main(void) {
  if (test_tmpdir(g_ws, sizeof(g_ws), "cst-tools-2") != 0) {
    perror("tmpdir");
    return 1;
  }
  cst_tool_ctx_t ctx;
  memset(&ctx, 0, sizeof(ctx));
  ctx.workspace_root = g_ws;

  test_md_to_html(&ctx);
  test_read_pdf(&ctx);
  test_download_args(&ctx);
  test_session_search(&ctx);
  test_device_info(&ctx);

  test_rmrf(g_ws);
  if (nfail) {
    fprintf(stderr, "%d check(s) failed\n", nfail);
    return 1;
  }
  printf("test_tools_ext: OK\n");
  return 0;
}