#include <c_DirectedDFS.h>

/* Private recursive engine helper */
static void c_DirectedDFS_Internal(c_DirectedDFS_t* self, const c_Digraph_t* graph, c_size_t v) {
    self->marked[v] = C_TRUE;
    self->count++;

    c_AdjList_t* adj = &graph->adj_list[v];
    c_size_t size = (c_size_t)c_AdjList_GetSize(adj);

    for (c_size_t i = 0; i < size; ++i) {
        c_size_t w;
        if (c_AdjList_Get(adj, i, &w)!=C_ERR_OK) {
            continue;
        }
        if (!self->marked[w]) {
            c_DirectedDFS_Internal(self, graph, w);
        }
    }
}

c_err_t c_DirectedDFS_Init(c_DirectedDFS_t* self, const c_Digraph_t* graph, c_size_t s, c_Allocator_t* allocator) {
    if (!self || !graph || s >= graph->V) return C_ERR_PARAM;

    self->allocator = allocator?*allocator:c_DefaultAllocator;
    self->count = 0;
    self->marked = (c_bool_t*)c_Allocator_Calloc(&self->allocator, graph->V, sizeof(c_bool_t));
    if (!self->marked) return C_ERR_NOMEM;

    c_DirectedDFS_Internal(self, graph, s);
    return C_SUCCESS;
}

c_err_t c_DirectedDFS_InitMulti(c_DirectedDFS_t* self, const c_Digraph_t* graph, const c_size_t* sources, c_size_t source_count, c_Allocator_t* allocator) {
    if (!self || !graph || !sources || source_count == 0) return C_ERR_PARAM;

    self->allocator = allocator?*allocator:c_DefaultAllocator;
    self->count = 0;
    self->marked = (c_bool_t*)c_Allocator_Calloc(&self->allocator, graph->V, sizeof(c_bool_t));
    if (!self->marked) return C_ERR_NOMEM;

    for (c_size_t i = 0; i < source_count; ++i) {
        c_size_t s = sources[i];
        if (s < graph->V && !self->marked[s]) {
            c_DirectedDFS_Internal(self, graph, s);
        }
    }
    return C_SUCCESS;
}

void c_DirectedDFS_Destroy(c_DirectedDFS_t* self) {
    if (!self) return;
    if (self->marked) {
        c_Allocator_Free(&self->allocator, self->marked);
        self->marked = NULL;
    }
    self->count = 0;
}