1 files changed, 241 insertions, 0 deletions
diff --git a/src/goal.cpp b/src/goal.cpp
new file mode 100644
index 0000000..36aa271
--- /dev/null
+++ b/src/goal.cpp
@@ -0,0 +1,241 @@
+#include "goal.h"
+
+#include <ctype.h>
+#include <stdlib.h>
+#include <string.h>
+
+static const char *const GOAL_PREAMBLE =
+    "You are the reviewer for a terminal coding agent that is working toward a "
+    "goal. You are given the goal — a success condition — and the agent's most "
+    "recent reply. Decide whether the goal is fully met.\n"
+    "\n"
+    "Reply with exactly two lines:\n"
+    "1. Either `MET` or `NOT MET` — your verdict.\n"
+    "2. One short sentence: if met, what was accomplished; if not, the single "
+    "most important gap to fix next.\n"
+    "\n"
+    "Be strict: the goal is met only when the stated success condition is "
+    "clearly satisfied — not merely started, in progress, or partially done. "
+    "Do not give the agent the benefit of the doubt, and do not add commentary "
+    "beyond the two lines.";
+
+void goal_spec_free(goal_spec *s)
+{
+    if (!s)
+        return;
+    free(s->criteria);
+    s->criteria = NULL;
+}
+
+void goal_report_free(goal_report *r)
+{
+    if (!r)
+        return;
+    free(r->criteria);
+    free(r);
+}
+
+const char *goal_evaluator_preamble(void)
+{
+    return GOAL_PREAMBLE;
+}
+
+static bool str_eq_i(const char *s, size_t n, const char *word)
+{
+    size_t wn = strlen(word);
+    if (n != wn)
+        return false;
+    for (size_t i = 0; i < wn; i++) {
+        char a = s[i], b = word[i];
+        if (a >= 'a' && a <= 'z')
+            a = (char)(a - 'a' + 'A');
+        if (b >= 'a' && b <= 'z')
+            b = (char)(b - 'a' + 'A');
+        if (a != b)
+            return false;
+    }
+    return true;
+}
+
+static int parse_tries(const char *s, size_t n, unsigned long *out, char **err)
+{
+    size_t tlen;
+    const char *t = xtrim_span(s, n, &tlen);
+    size_t digits = 0;
+    while (digits < tlen && t[digits] >= '0' && t[digits] <= '9')
+        digits++;
+    if (digits == 0) {
+        *err = xstrdup(
+            "expected a number of tries after `stop after`, e.g. "
+            "`stop after 5 tries`");
+        return 0;
+    }
+    /* After the digits: end of input, or the word `tries` as a whole word.
+     * "5xyz" is rejected; "5 tries" is the canonical form. */
+    size_t rest = digits;
+    while (rest < tlen && isspace((unsigned char)t[rest]))
+        rest++;
+    if (rest != tlen) {
+        size_t wn = 5;
+        bool word_ok = (tlen - rest) >= wn;
+        if (word_ok) {
+            const char *w = "tries";
+            for (size_t i = 0; i < wn; i++) {
+                char a = t[rest + i], b = w[i];
+                if (a >= 'a' && a <= 'z')
+                    a = (char)(a - 'a' + 'A');
+                if (b >= 'a' && b <= 'z')
+                    b = (char)(b - 'a' + 'A');
+                if (a != b) {
+                    word_ok = false;
+                    break;
+                }
+            }
+        }
+        if (!word_ok || ((tlen - rest) > wn &&
+                         isalpha((unsigned char)t[rest + wn]))) {
+            *err = xstrdup(
+                "expected a number of tries after `stop after`, e.g. "
+                "`stop after 5 tries`");
+            return 0;
+        }
+    }
+    unsigned long value = 0;
+    for (size_t i = 0; i < digits; i++) {
+        value = value * 10UL + (unsigned long)(t[i] - '0');
+        if (value > 4294967295UL) {
+            *err = xstrdup(
+                "expected a number of tries after `stop after`, e.g. "
+                "`stop after 5 tries`");
+            return 0;
+        }
+    }
+    if (value == 0) {
+        *err = xstrdup("the goal needs at least 1 try");
+        return 0;
+    }
+    *out = value;
+    return 1;
+}
+
+int goal_parse(const char *input, goal_spec *out, char **err)
+{
+    /* Zero on entry so a failed parse leaves a freeable, empty spec. */
+    memset(out, 0, sizeof *out);
+    const char *src = input ? input : "";
+    size_t slen = strlen(src);
+    size_t tlen;
+    const char *t = xtrim_span(src, slen, &tlen);
+    if (tlen == 0) {
+        *err = xstrdup(
+            "give the goal its success criteria, e.g. "
+            "`/goal all tests pass, stop after 5 tries`");
+        return 0;
+    }
+
+    const char marker[] = "stop after";
+    size_t mlen = sizeof(marker) - 1;
+    /* rfind: last occurrence of marker in [t, t+tlen). */
+    const char *hit = NULL;
+    const char *p = t;
+    while (tlen - (size_t)(p - t) >= mlen) {
+        void *m = memmem(p, tlen - (size_t)(p - t), marker, mlen);
+        if (!m)
+            break;
+        hit = (const char* ) m;
+        p = (const char *)m + 1;
+    }
+
+    if (!hit) {
+        out->criteria = xstrndup(t, tlen);
+        out->max_tries = GOAL_DEFAULT_MAX_TRIES;
+        return 1;
+    }
+
+    size_t pre_len = (size_t)(hit - t);
+    size_t clen;
+    const char *crit = xtrim_span(t, pre_len, &clen);
+    while (clen > 0 && crit[clen - 1] == ',')
+        clen--;
+    crit = xtrim_span(crit, clen, &clen);
+    if (clen == 0) {
+        *err = xstrdup(
+            "give the goal its success criteria before `stop after`, e.g. "
+            "`/goal all tests pass, stop after 5 tries`");
+        return 0;
+    }
+    const char *tail = hit + mlen;
+    if (!parse_tries(tail, tlen - (size_t)(tail - t), &out->max_tries, err))
+        return 0;
+    out->criteria = xstrndup(crit, clen);
+    return 1;
+}
+
+char *goal_prompt(const goal_spec *spec, unsigned long attempt,
+                  const char *feedback)
+{
+    const char *crit = spec->criteria ? spec->criteria : "";
+    if (attempt <= 1)
+        return xstrfmt(
+            "Work toward this goal until it is fully met:\n\n%s\n\n"
+            "Judge your own progress, verify it, and keep going if it is not "
+            "done. When you are confident the goal is fully met, stop and say "
+            "what you did.",
+            crit);
+    const char *fb = feedback ? feedback : "no specific feedback was given";
+    return xstrfmt(
+        "You are on attempt %lu of %lu toward this goal:\n\n%s\n\n"
+        "A reviewer judged the goal NOT yet met: %s\n\n"
+        "Address that gap and keep working. When you are confident the goal is "
+        "fully met, stop and say what you did.",
+        attempt, spec->max_tries, crit, fb);
+}
+
+/* True if `needle` occurs in `hay` as a whole word (A-Z only; `hay` is
+ * already upper-cased). Prevents "MET" matching inside "UNMET". */
+static bool has_word(const char *hay, const char *needle) {
+    size_t nl = strlen(needle);
+    const char *p = hay;
+    while ((p = strstr(p, needle)) != NULL) {
+        bool left_ok = (p == hay) || (p[-1] < 'A' || p[-1] > 'Z');
+        bool right_ok = (p[nl] < 'A' || p[nl] > 'Z');
+        if (left_ok && right_ok)
+            return true;
+        p += (nl > 0 ? nl : 1);
+    }
+    return false;
+}
+
+void goal_parse_verdict(const char *reply, goal_verdict *out)
+{
+    const char *src = reply ? reply : "";
+    char *upper = xstrdup(src);
+    for (char *c = upper; *c; c++)
+        if (*c >= 'a' && *c <= 'z')
+            *c = (char)(*c - 'a' + 'A');
+    out->met = has_word(upper, "MET") && !has_word(upper, "NOT MET") &&
+               !has_word(upper, "UNMET");
+    free(upper);
+
+    const char *chosen = NULL;
+    size_t chosen_len = 0;
+    const char *p = src;
+    while (*p) {
+        const char *nl = strchr(p, '\n');
+        size_t linelen = nl ? (size_t)(nl - p) : strlen(p);
+        size_t tlen;
+            const char *line = xtrim_span(p, linelen, &tlen);
+        if (tlen > 0 && !str_eq_i(line, tlen, "MET") &&
+            !str_eq_i(line, tlen, "NOT MET")) {
+            chosen = line;
+            chosen_len = tlen;
+            break;
+        }
+        if (!nl)
+            break;
+        p = nl + 1;
+    }
+    out->reason = chosen
+                      ? xstrndup(chosen, chosen_len)
+                      : xstrdup("the reviewer did not give a reason");
+}