#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "slex.h"
#include "scc.h"
static double evaluate(scc_syntax_node* node) {
    if (!node) return 0.0;

    switch (node->id) {
        case scc_id_number_expr: {
            if (node->child_count > 0 && node->children[0].type == scc_segment) {
                slex_segment* seg = (slex_segment*)node->children[0].data;
                return atof(seg->head);
            }
            return 0.0;
        }
        case scc_id_group_expr: {
            if (node->child_count > 0 && node->children[0].type == scc_node) {
                return evaluate((scc_syntax_node*)node->children[0].data);
            }
            return 0.0;
        }
        case scc_id_term:
        case scc_id_expr: {
            if (node->child_count > 0 && node->children[0].type == scc_node) {
                return evaluate((scc_syntax_node*)node->children[0].data);
            }
            return 0.0;
        }
        case scc_id_add_expr: {
            if (node->child_count == 3 && node->children[0].type == scc_node && node->children[2].type == scc_node) {
                return evaluate((scc_syntax_node*)node->children[0].data) + evaluate((scc_syntax_node*)node->children[2].data);
            }
            return 0.0;
        }
        case scc_id_sub_expr: {
            if (node->child_count == 3 && node->children[0].type == scc_node && node->children[2].type == scc_node) {
                return evaluate((scc_syntax_node*)node->children[0].data) - evaluate((scc_syntax_node*)node->children[2].data);
            }
            return 0.0;
        }
        case scc_id_mul_expr: {
            if (node->child_count == 3 && node->children[0].type == scc_node && node->children[2].type == scc_node) {
                return evaluate((scc_syntax_node*)node->children[0].data) * evaluate((scc_syntax_node*)node->children[2].data);
            }
            return 0.0;
        }
        case scc_id_div_expr: {
            if (node->child_count == 3 && node->children[0].type == scc_node && node->children[2].type == scc_node) {
                double divisor = evaluate((scc_syntax_node*)node->children[2].data);
                if (divisor == 0.0) {
                    fprintf(stderr, "Error: Division by zero!\n");
                    return 0.0;
                }
                return evaluate((scc_syntax_node*)node->children[0].data) / divisor;
            }
            return 0.0;
        }
        default:
            return 0.0;
    }
}

static void print_ast(scc_syntax_node* node, int indent) {
    if (!node) return;
    for (int i = 0; i < indent; i++) printf("  ");
    printf("Node: %s (id=%d, child_count=%lld)\n", node->syntax_name, node->id, (long long)node->child_count);
    for (uint64_t i = 0; i < node->child_count; i++) {
        scc_syntax_node_enclosure* child = &node->children[i];
        if (child->type == scc_node) {
            print_ast((scc_syntax_node*)child->data, indent + 1);
        } else {
            slex_segment* seg = (slex_segment*)child->data;
            for (int j = 0; j < indent + 1; j++) printf("  ");
            printf("Segment: '%s' (tag=%d, id=%d)\n", seg->head, seg->tag, seg->id);
        }
    }
}

int main(int ac, char** av) {
    char* input_expr = "3 + 4 * ( 5 - 2 )";
    if(ac==2){
        input_expr=av[1];
    }
    printf("Lexing input expression: \"%s\"\n", input_expr);

    slex_segment* lexer_head = NULL;
    if (!slex_cstr((char*)input_expr, "input", &lexer_head)) {
        fprintf(stderr, "Error: Lexical analysis failed\n");
        return 1;
    }

    printf("Parsing lexical segments...\n");
    scc_syntax_node* root = NULL;
    if (!scc_parse(lexer_head, &root)) {
        fprintf(stderr, "Error: Parsing failed\n");
        slex_free(lexer_head);
        return 1;
    }

    printf("\nAST Structure:\n");
    print_ast(root, 0);

    double result = evaluate(root);
    printf("\nEvaluation Result:\n");
    printf("%s = %g\n", input_expr, result);

    scc_free(root);
    slex_free(lexer_head);
    return 0;
}