/*
 * par2serial-cc: ast.c - AST construction and debug printing
 */
#include "ast.h"

ASTNode *ast_new(Arena *a, NodeType type, SourceLoc loc) {
    ASTNode *n = (ASTNode *)arena_alloc(a, sizeof(ASTNode));
    memset(n, 0, sizeof(ASTNode));
    n->type = type;
    n->loc  = loc;
    return n;
}

ASTType *ast_new_type(Arena *a, TypeKind kind) {
    ASTType *t = (ASTType *)arena_alloc(a, sizeof(ASTType));
    memset(t, 0, sizeof(ASTType));
    t->kind = kind;
    t->array_size = -1;
    return t;
}

ASTType *ast_ptr_type(Arena *a, ASTType *base) {
    ASTType *t = ast_new_type(a, TYPE_POINTER);
    t->base = base;
    return t;
}

ASTType *ast_array_type(Arena *a, ASTType *base, int size) {
    ASTType *t = ast_new_type(a, TYPE_ARRAY);
    t->base = base;
    t->array_size = size;
    return t;
}

/* ── String representations ──────────────────────────────── */
const char *node_type_str(NodeType t) {
    static const char *names[] = {
        [NODE_PROGRAM]="Program", [NODE_FUNC_DECL]="FuncDecl",
        [NODE_VAR_DECL]="VarDecl", [NODE_PARAM]="Param",
        [NODE_STRUCT_DECL]="StructDecl",
        [NODE_BLOCK]="Block", [NODE_EXPR_STMT]="ExprStmt",
        [NODE_IF]="If", [NODE_WHILE]="While", [NODE_DO_WHILE]="DoWhile",
        [NODE_FOR]="For", [NODE_RETURN]="Return",
        [NODE_BREAK]="Break", [NODE_CONTINUE]="Continue",
        [NODE_BINARY]="Binary", [NODE_UNARY]="Unary",
        [NODE_POSTFIX]="Postfix", [NODE_ASSIGN]="Assign",
        [NODE_TERNARY]="Ternary", [NODE_CALL]="Call",
        [NODE_INDEX]="Index", [NODE_MEMBER]="Member",
        [NODE_ARROW]="Arrow", [NODE_CAST]="Cast",
        [NODE_SIZEOF]="Sizeof", [NODE_IDENT]="Ident",
        [NODE_INT_LIT]="IntLit", [NODE_FLOAT_LIT]="FloatLit",
        [NODE_STRING_LIT]="StringLit", [NODE_CHAR_LIT]="CharLit",
        [NODE_COMMA_EXPR]="CommaExpr",
        [NODE_ADDR_OF]="AddrOf", [NODE_DEREF]="Deref",
        [NODE_PARALLEL_FOR]="ParallelFor",
        [NODE_PARALLEL_REDUCE]="ParallelReduce",
        [NODE_PARALLEL_SCAN]="ParallelScan",
        [NODE_PARALLEL_MAP]="ParallelMap",
        [NODE_BARRIER]="Barrier",
        [NODE_SHARED_DECL]="SharedDecl",
        [NODE_TILE_HINT]="TileHint",
        [NODE_SIMD_HINT]="SimdHint",
        [NODE_MEMORY_LAYOUT]="MemoryLayout",
        [NODE_ATOMIC_ADD]="AtomicAdd",
        [NODE_ATOMIC_CAS]="AtomicCAS",
        [NODE_PREPROC]="Preproc",
    };
    if (t >= 0 && t < NODE_TYPE_COUNT && names[t]) return names[t];
    return "Unknown";
}

const char *op_type_str(OpType op) {
    static const char *ops[] = {
        [OP_ADD]="+", [OP_SUB]="-", [OP_MUL]="*", [OP_DIV]="/", [OP_MOD]="%",
        [OP_AND]="&", [OP_OR]="|", [OP_XOR]="^", [OP_NOT]="~", [OP_LNOT]="!",
        [OP_LSHIFT]="<<", [OP_RSHIFT]=">>",
        [OP_EQ]="==", [OP_NEQ]="!=", [OP_LT]="<", [OP_GT]=">",
        [OP_LE]="<=", [OP_GE]=">=", [OP_LAND]="&&", [OP_LOR]="||",
        [OP_NEG]="-", [OP_POS]="+", [OP_INC]="++", [OP_DEC]="--",
        [OP_POST_INC]="(post)++", [OP_POST_DEC]="(post)--",
        [OP_ASSIGN]="=",
        [OP_ADD_ASSIGN]="+=", [OP_SUB_ASSIGN]="-=",
        [OP_MUL_ASSIGN]="*=", [OP_DIV_ASSIGN]="/=",
        [OP_MOD_ASSIGN]="%=", [OP_AND_ASSIGN]="&=",
        [OP_OR_ASSIGN]="|=", [OP_XOR_ASSIGN]="^=",
        [OP_LSHIFT_ASSIGN]="<<=", [OP_RSHIFT_ASSIGN]=">>=",
        [OP_COMMA]=",",
    };
    return ops[op];
}

/* ── Pretty printer ──────────────────────────────────────── */
static void indent(int level) {
    for (int i = 0; i < level; i++) printf("  ");
}

void ast_print(ASTNode *node, int ind) {
    if (!node) { indent(ind); printf("(null)\n"); return; }
    indent(ind);
    printf("%s", node_type_str(node->type));

    switch (node->type) {
    case NODE_PROGRAM:
        printf(" (%zu decls)\n", node->program.decls.len);
        for (size_t i = 0; i < node->program.decls.len; i++)
            ast_print(node->program.decls.data[i], ind + 1);
        break;

    case NODE_FUNC_DECL:
        printf(" '%s' (%zu params)\n", node->func.name, node->func.params.len);
        for (size_t i = 0; i < node->func.params.len; i++)
            ast_print(node->func.params.data[i], ind + 1);
        if (node->func.body)
            ast_print(node->func.body, ind + 1);
        break;

    case NODE_VAR_DECL:
        printf(" '%s'", node->var.name);
        if (node->var.init) { printf(" =\n"); ast_print(node->var.init, ind + 1); }
        else printf("\n");
        break;

    case NODE_PARAM:
        printf(" '%s'\n", node->param.name);
        break;

    case NODE_BLOCK:
        printf(" (%zu stmts)\n", node->block.stmts.len);
        for (size_t i = 0; i < node->block.stmts.len; i++)
            ast_print(node->block.stmts.data[i], ind + 1);
        break;

    case NODE_IF:
        printf("\n");
        indent(ind + 1); printf("cond:\n"); ast_print(node->if_stmt.cond, ind + 2);
        indent(ind + 1); printf("then:\n"); ast_print(node->if_stmt.then_body, ind + 2);
        if (node->if_stmt.else_body) {
            indent(ind + 1); printf("else:\n"); ast_print(node->if_stmt.else_body, ind + 2);
        }
        break;

    case NODE_FOR:
        printf("\n");
        if (node->for_stmt.init) { indent(ind+1); printf("init:\n"); ast_print(node->for_stmt.init, ind+2); }
        if (node->for_stmt.cond) { indent(ind+1); printf("cond:\n"); ast_print(node->for_stmt.cond, ind+2); }
        if (node->for_stmt.step) { indent(ind+1); printf("step:\n"); ast_print(node->for_stmt.step, ind+2); }
        indent(ind+1); printf("body:\n"); ast_print(node->for_stmt.body, ind+2);
        break;

    case NODE_WHILE:
    case NODE_DO_WHILE:
        printf("\n");
        ast_print(node->while_stmt.cond, ind + 1);
        ast_print(node->while_stmt.body, ind + 1);
        break;

    case NODE_RETURN:
        printf("\n");
        if (node->ret.value) ast_print(node->ret.value, ind + 1);
        break;

    case NODE_EXPR_STMT:
        printf("\n");
        ast_print(node->expr_stmt.expr, ind + 1);
        break;

    case NODE_BINARY:
        printf(" '%s'\n", op_type_str(node->binary.op));
        ast_print(node->binary.left, ind + 1);
        ast_print(node->binary.right, ind + 1);
        break;

    case NODE_UNARY:
        printf(" '%s'\n", op_type_str(node->unary.op));
        ast_print(node->unary.operand, ind + 1);
        break;

    case NODE_ASSIGN:
        printf(" '%s'\n", op_type_str(node->assign.op));
        ast_print(node->assign.target, ind + 1);
        ast_print(node->assign.value, ind + 1);
        break;

    case NODE_CALL:
        printf("\n");
        indent(ind + 1); printf("func:\n"); ast_print(node->call.func, ind + 2);
        for (size_t i = 0; i < node->call.args.len; i++) {
            indent(ind + 1); printf("arg %zu:\n", i);
            ast_print(node->call.args.data[i], ind + 2);
        }
        break;

    case NODE_INDEX:
        printf("\n");
        ast_print(node->index.array, ind + 1);
        ast_print(node->index.index, ind + 1);
        break;

    case NODE_IDENT:
        printf(" '%s'\n", node->ident.name);
        break;

    case NODE_INT_LIT:
        printf(" %ld\n", (long)node->int_lit.value);
        break;

    case NODE_FLOAT_LIT:
        printf(" %g\n", node->float_lit.value);
        break;

    case NODE_STRING_LIT:
        printf(" \"%s\"\n", node->string_lit.value);
        break;

    case NODE_PARALLEL_FOR:
        printf(" iter='%s'\n", node->par_for.iter_var);
        indent(ind+1); printf("lo:\n"); ast_print(node->par_for.lo, ind+2);
        indent(ind+1); printf("hi:\n"); ast_print(node->par_for.hi, ind+2);
        indent(ind+1); printf("body:\n"); ast_print(node->par_for.body, ind+2);
        break;

    case NODE_PARALLEL_REDUCE:
        printf(" accum='%s' iter='%s'\n", node->par_reduce.accum_var, node->par_reduce.iter_var);
        indent(ind+1); printf("lo:\n"); ast_print(node->par_reduce.lo, ind+2);
        indent(ind+1); printf("hi:\n"); ast_print(node->par_reduce.hi, ind+2);
        indent(ind+1); printf("body:\n"); ast_print(node->par_reduce.body, ind+2);
        break;

    case NODE_TILE_HINT:
        printf(" target='%s' size=%d\n", node->tile_hint.target, node->tile_hint.tile_size);
        break;

    case NODE_SIMD_HINT:
        printf(" target='%s'\n", node->simd_hint.target);
        break;

    case NODE_PREPROC:
        printf(" '%s'\n", node->preproc.text);
        break;

    default:
        printf("\n");
        break;
    }
}