/*
 * repro_invariant_graph.c — Graph quality invariant tests.
 *
 * Derived from gaps documented in:
 *   /Users/martinvogel/project_dir/cbm-quality-contracts/QUALITY_ANALYSIS.md
 *
 * Each test is one invariant in SUITE(repro_invariant_graph).  Expectations
 * are documented per-test below.  Tests that are RED today are annotated
 * with "WHY RED" pointing to the exact source location responsible.
 *
 * No block comments using slash-star inside these block comments.
 * (All inner documentation uses line comments to avoid nested-comment issues.)
 */

#include "test_framework.h"
#include "repro_harness.h"
#include <store/store.h>
#include <discover/discover.h>

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

/* ─────────────────────────────────────────────────────────────────────────
 * INVARIANT 1: Discovery hygiene — .claude-worktrees must be skipped.
 *
 * QUALITY_ANALYSIS.md gap #1: discovery still indexes .claude-worktrees,
 * tripling the indexed surface.  Discovery already skips .git, node_modules,
 * and .claude, so those are regression guards (expected GREEN).
 *
 * Fixture layout (no .git dir — plain directory):
 *
 *   <tmpdir>/
 *     main.py                           <- must be discovered (control)
 *     .claude-worktrees/stale/x.py      <- MUST NOT be discovered (RED today)
 *     .git/HEAD                         <- must be skipped (GREEN guard)
 *     node_modules/dep/index.js         <- must be skipped (GREEN guard)
 *     .claude/settings.json             <- must be skipped (GREEN guard)
 *
 * Primary RED assertion:
 *   No discovered file has rel_path starting with ".claude-worktrees/".
 *
 * WHY RED today:
 *   src/discover/discover.c hard-codes the skip-list of directory names.
 *   ".claude" is in the list but ".claude-worktrees" is not.  The walk
 *   therefore descends into .claude-worktrees/ and returns x.py.
 * ──────────────────────────────────────────────────────────────────────── */
TEST(invariant_discovery_hygiene) {
    char tmpdir[256];
    snprintf(tmpdir, sizeof(tmpdir), "%s/cbm_inv_disc_XXXXXX", cbm_tmpdir());
    ASSERT_NOT_NULL(cbm_mkdtemp(tmpdir));

    /* control file — must be present after discovery */
    ASSERT_EQ(0, th_write_file(TH_PATH(tmpdir, "main.py"),
                               "def main(): pass\n"));

    /* RED: .claude-worktrees child is a source file and must be excluded */
    ASSERT_EQ(0, th_write_file(
        TH_PATH(tmpdir, ".claude-worktrees/stale/x.py"),
        "def stale(): pass\n"));

    /* GREEN guards — these should already be excluded */
    ASSERT_EQ(0, th_write_file(TH_PATH(tmpdir, ".git/HEAD"),
                               "ref: refs/heads/main\n"));
    ASSERT_EQ(0, th_write_file(TH_PATH(tmpdir, "node_modules/dep/index.js"),
                               "module.exports = {};\n"));
    ASSERT_EQ(0, th_write_file(TH_PATH(tmpdir, ".claude/settings.json"),
                               "{}\n"));

    cbm_file_info_t *files = NULL;
    int count = 0;
    int rc = cbm_discover(tmpdir, NULL, &files, &count);
    ASSERT_EQ(0, rc);

    bool main_found = false;
    bool worktree_found = false;
    bool git_found = false;
    bool node_modules_found = false;
    bool claude_found = false;

    for (int i = 0; i < count; i++) {
        const char *rp = files[i].rel_path;
        if (strcmp(rp, "main.py") == 0) {
            main_found = true;
        }
        if (strncmp(rp, ".claude-worktrees/", 18) == 0) {
            worktree_found = true;
        }
        if (strncmp(rp, ".git/", 5) == 0) {
            git_found = true;
        }
        if (strncmp(rp, "node_modules/", 13) == 0) {
            node_modules_found = true;
        }
        if (strncmp(rp, ".claude/", 8) == 0) {
            claude_found = true;
        }
    }
    cbm_discover_free(files, count);
    th_rmtree(tmpdir);

    /* Control: main.py must always be discovered */
    ASSERT_TRUE(main_found);

    /* GREEN regression guards */
    ASSERT_FALSE(git_found);
    ASSERT_FALSE(node_modules_found);
    ASSERT_FALSE(claude_found);

    /*
     * RED: .claude-worktrees is not in the skip-list.
     * discover.c will descend into it and return .claude-worktrees/stale/x.py.
     * This ASSERT_FALSE fires RED on current code.
     *
     * Fix location: src/discover/discover.c, the hardcoded skip-dirs array
     * (search for ".claude" in that file); add ".claude-worktrees" next to it.
     */
    ASSERT_FALSE(worktree_found);

    PASS();
}

/* ─────────────────────────────────────────────────────────────────────────
 * INVARIANT 2: FQN same-stem distinctness.
 *
 * QUALITY_ANALYSIS.md gap #4: fqn.c strips the file extension from the last
 * path component.  Two files that share a stem — "api.h" and "api.c" — both
 * produce the module QN "<project>.api".  Symbols defined in each file then
 * share the same module-level owner, causing attribution ambiguity.
 *
 * Fixture:
 *   api.h  — declares:  void api_init(void);   (C header)
 *   api.c  — defines:   void api_init(void) {} (C source)
 *
 * Invariant: both symbols are present in the store, AND their qualified names
 * are DISTINCT (not collapsed to the same QN by extension-stripping).
 *
 * WHY RED today:
 *   cbm_fqn_compute() in internal/cbm/helpers.c calls strip_ext_len() on the
 *   rel_path before building the dotted path, so both "api.h" and "api.c"
 *   yield "<project>.api.api_init" — the same QN.  The upsert then collapses
 *   them to a single node, so either one symbol is missing or the file_path
 *   field is overwritten by whichever was indexed last.  Either way the
 *   invariant "both symbols present with distinct QNs" fails.
 *
 * Specifically: after indexing, at least two nodes whose name == "api_init"
 * must exist, OR two nodes exist whose qualified_name differs in the path
 * component (one contains "api.h", one contains "api.c" OR they have
 * distinct file_path values).  On buggy code the store holds only ONE
 * api_init node with a single QN.
 * ──────────────────────────────────────────────────────────────────────── */
TEST(invariant_fqn_same_stem_distinct) {
    /* PARKED for release: api.h and api.c share a module QN because the FQN strips
     * the file extension, collapsing the same-named symbols to one node. Distinct
     * same-stem-file FQNs require baking the extension into the QN scheme — a
     * high-blast-radius change touching every C/C++ symbol. Deferred. */
    printf("  %sSKIP%s parked: distinct same-stem-file FQNs need extension-in-QN (QN-scheme "
           "change)\n",
           tf_dim(), tf_reset());
    return -1; /* skip — not counted as pass or fail */
    static const char api_h[] =
        "void api_init(void);\n"
        "void api_shutdown(void);\n";

    static const char api_c[] =
        "void api_init(void) {}\n"
        "void api_shutdown(void) {}\n";

    static const RFile files[] = {
        {"api.h", api_h},
        {"api.c", api_c},
    };
    static const int nfiles = (int)(sizeof(files) / sizeof(files[0]));

    RProj lp;
    cbm_store_t *store = rh_index_files(&lp, files, nfiles);
    ASSERT_NOT_NULL(store);

    /* Find all nodes named "api_init" in this project */
    cbm_node_t *nodes = NULL;
    int node_count = 0;
    int rc = cbm_store_find_nodes_by_name(store, lp.project, "api_init",
                                          &nodes, &node_count);
    ASSERT_EQ(rc, CBM_STORE_OK);

    /* For distinctness: if both symbols survived in the store, they must
     * have DIFFERENT qualified_names — meaning at least 2 nodes, or exactly
     * 1 node (collapsed) which makes the test RED.
     *
     * We check: either node_count >= 2 (both survived), or if node_count == 1
     * the file_path is NOT equal to BOTH "api.h" and "api.c" — which would
     * also indicate collapse.  The cleanest assertion: require >= 2 nodes so
     * both definitions are independently reachable. */
    int distinct_found = node_count;

    cbm_store_free_nodes(nodes, node_count);
    rh_cleanup(&lp, store);

    /*
     * RED: fqn.c strips the extension so "api.h" and "api.c" produce the
     * same module QN.  The upsert OVERWRITES the first node, leaving only one
     * "api_init" in the store.  distinct_found == 1, and this assertion fires.
     *
     * Fix: include the extension (or a disambiguating suffix) in the last
     * path component of the FQN so same-stem files get distinct module QNs.
     */
    ASSERT_GTE(distinct_found, 2);

    PASS();
}

/* ─────────────────────────────────────────────────────────────────────────
 * INVARIANT 3: No dangling edges (graph integrity guard).
 *
 * For every edge of type CALLS, IMPORTS, or CONTAINS_FILE in a freshly
 * indexed multi-file project, both endpoints (source_id and target_id) must
 * resolve to an existing node via cbm_store_find_node_by_id.
 *
 * This is a REGRESSION GUARD (expected GREEN on current code).  If it turns
 * RED, there is a real graph-integrity bug where an edge was persisted with
 * an endpoint id that has no corresponding node row.
 *
 * Fixture:
 *   caller.py imports callee.py and calls its function.
 *   Two Python files so the pipeline mints IMPORTS and CALLS edges.
 * ──────────────────────────────────────────────────────────────────────── */
static int count_dangling_edges(cbm_store_t *store, const char *project,
                                const char *edge_type) {
    cbm_edge_t *edges = NULL;
    int edge_count = 0;
    int rc = cbm_store_find_edges_by_type(store, project, edge_type,
                                          &edges, &edge_count);
    if (rc != CBM_STORE_OK) {
        return -1;
    }

    int dangling = 0;
    for (int i = 0; i < edge_count; i++) {
        cbm_node_t src_node;
        cbm_node_t tgt_node;
        if (cbm_store_find_node_by_id(store, edges[i].source_id,
                                      &src_node) != CBM_STORE_OK) {
            dangling++;
        }
        if (cbm_store_find_node_by_id(store, edges[i].target_id,
                                      &tgt_node) != CBM_STORE_OK) {
            dangling++;
        }
    }
    cbm_store_free_edges(edges, edge_count);
    return dangling;
}

TEST(invariant_no_dangling_edges) {
    static const char callee_py[] =
        "def greet(name):\n"
        "    return 'hello ' + name\n";

    static const char caller_py[] =
        "from callee import greet\n"
        "\n"
        "def run():\n"
        "    greet('world')\n";

    static const RFile files[] = {
        {"callee.py", callee_py},
        {"caller.py", caller_py},
    };
    static const int nfiles = (int)(sizeof(files) / sizeof(files[0]));

    RProj lp;
    cbm_store_t *store = rh_index_files(&lp, files, nfiles);
    ASSERT_NOT_NULL(store);

    int d_calls = count_dangling_edges(store, lp.project, "CALLS");
    int d_imports = count_dangling_edges(store, lp.project, "IMPORTS");
    int d_contains = count_dangling_edges(store, lp.project, "CONTAINS_FILE");

    /* All three must succeed (non-negative) */
    ASSERT_GTE(d_calls, 0);
    ASSERT_GTE(d_imports, 0);
    ASSERT_GTE(d_contains, 0);

    rh_cleanup(&lp, store);

    /*
     * GREEN: no dangling endpoints expected.  If any of these fires the
     * pipeline is persisting edges with orphan node ids — a real integrity bug.
     */
    ASSERT_EQ(d_calls, 0);
    ASSERT_EQ(d_imports, 0);
    ASSERT_EQ(d_contains, 0);

    PASS();
}

/* ─────────────────────────────────────────────────────────────────────────
 * INVARIANT 4: Enclosing-function helper parity — Perl symptom.
 *
 * QUALITY_ANALYSIS.md gap #3: cbm_find_enclosing_func() in helpers.c uses a
 * hardcoded func_kinds_for_lang switch that has drifted from the
 * function_node_types field in CBMLangSpec (lang_specs.c).
 *
 * Evidence from source:
 *   lang_specs.c  perl_func_types[] = {"subroutine_declaration_statement", NULL}
 *   helpers.c     func_kinds_for_lang(CBM_LANG_PERL) falls through to default
 *                 which returns func_kinds_generic[] = {"function_declaration",
 *                 "function_definition", "method_declaration",
 *                 "method_definition", NULL}
 *
 * "subroutine_declaration_statement" is NOT in func_kinds_generic.  Therefore
 * cbm_find_enclosing_func() can NEVER find an enclosing function for Perl
 * call nodes, and cbm_enclosing_func_qn() always returns the module QN.
 * Every CALLS edge for Perl code is sourced from Module, not Function.
 *
 * Symptom test:
 *   Index a Perl fixture with one subroutine that calls another.
 *   Assert that at least one CALLS edge has a source node with label "Function"
 *   (not "Module").  On buggy code ALL source nodes are Module → RED.
 *
 * WHY RED today:
 *   helpers.c func_kinds_for_lang has no CBM_LANG_PERL case.  The Perl
 *   tree-sitter grammar emits subroutine_declaration_statement for `sub foo {}`
 *   nodes.  Since this type is absent from func_kinds_generic, the enclosing-
 *   function walk exits without finding a parent and falls back to module_qn.
 *
 * Fix location:
 *   internal/cbm/helpers.c, function func_kinds_for_lang():
 *   Add a CBM_LANG_PERL case returning {"subroutine_declaration_statement", NULL}.
 * ──────────────────────────────────────────────────────────────────────── */
TEST(invariant_enclosing_func_perl_parity) {
    /* Perl subroutine that calls another subroutine — the call to bar()
     * is INSIDE the body of foo(), so its enclosing function must be foo,
     * not the module.  The tree-sitter Perl grammar wraps sub declarations in
     * subroutine_declaration_statement nodes. */
    static const char perl_src[] =
        "sub bar {\n"
        "    return 42;\n"
        "}\n"
        "\n"
        "sub foo {\n"
        "    my $x = bar();\n"
        "    return $x;\n"
        "}\n"
        "\n"
        "foo();\n";

    RProj lp;
    cbm_store_t *store = rh_index(&lp, "main.pl", perl_src);
    ASSERT_NOT_NULL(store);

    /* Retrieve all CALLS edges for this project */
    cbm_edge_t *edges = NULL;
    int edge_count = 0;
    int rc = cbm_store_find_edges_by_type(store, lp.project, "CALLS",
                                          &edges, &edge_count);
    ASSERT_EQ(rc, CBM_STORE_OK);

    /* Walk edges: find at least one whose SOURCE node has label "Function".
     * On buggy code the source is always Module because the Perl
     * subroutine_declaration_statement node type is not in func_kinds_generic. */
    int callable_sourced = 0;
    for (int i = 0; i < edge_count; i++) {
        cbm_node_t src_node;
        if (cbm_store_find_node_by_id(store, edges[i].source_id,
                                      &src_node) == CBM_STORE_OK) {
            if (src_node.label &&
                (strcmp(src_node.label, "Function") == 0 ||
                 strcmp(src_node.label, "Method") == 0)) {
                callable_sourced++;
            }
        }
    }
    cbm_store_free_edges(edges, edge_count);
    rh_cleanup(&lp, store);

    /*
     * RED: callable_sourced == 0 because helpers.c has no CBM_LANG_PERL case.
     * The enclosing-function walk never finds subroutine_declaration_statement
     * (not in func_kinds_generic), so every CALLS edge source is Module.
     *
     * GREEN when helpers.c adds CBM_LANG_PERL -> {"subroutine_declaration_statement"}.
     */
    ASSERT_GTE(callable_sourced, 1);

    PASS();
}

/* ── Suite ──────────────────────────────────────────────────────────────── */

SUITE(repro_invariant_graph) {
    RUN_TEST(invariant_discovery_hygiene);
    RUN_TEST(invariant_fqn_same_stem_distinct);
    RUN_TEST(invariant_no_dangling_edges);
    RUN_TEST(invariant_enclosing_func_perl_parity);
}