<?php

namespace PhpParser;

use PhpParser\Node\Expr;
use PhpParser\Node\Stmt;

abstract class PrettyPrinterAbstract
{
    protected $precedenceMap = array(
        // [precedence, associativity] where for the latter -1 is %left, 0 is %nonassoc and 1 is %right
        'Expr_BinaryOp_Pow'            => array( 0,  1),
        'Expr_BitwiseNot'              => array( 1,  1),
        'Expr_PreInc'                  => array( 1,  1),
        'Expr_PreDec'                  => array( 1,  1),
        'Expr_PostInc'                 => array( 1, -1),
        'Expr_PostDec'                 => array( 1, -1),
        'Expr_UnaryPlus'               => array( 1,  1),
        'Expr_UnaryMinus'              => array( 1,  1),
        'Expr_Cast_Int'                => array( 1,  1),
        'Expr_Cast_Double'             => array( 1,  1),
        'Expr_Cast_String'             => array( 1,  1),
        'Expr_Cast_Array'              => array( 1,  1),
        'Expr_Cast_Object'             => array( 1,  1),
        'Expr_Cast_Bool'               => array( 1,  1),
        'Expr_Cast_Unset'              => array( 1,  1),
        'Expr_ErrorSuppress'           => array( 1,  1),
        'Expr_Instanceof'              => array( 2,  0),
        'Expr_BooleanNot'              => array( 3,  1),
        'Expr_BinaryOp_Mul'            => array( 4, -1),
        'Expr_BinaryOp_Div'            => array( 4, -1),
        'Expr_BinaryOp_Mod'            => array( 4, -1),
        'Expr_BinaryOp_Plus'           => array( 5, -1),
        'Expr_BinaryOp_Minus'          => array( 5, -1),
        'Expr_BinaryOp_Concat'         => array( 5, -1),
        'Expr_BinaryOp_ShiftLeft'      => array( 6, -1),
        'Expr_BinaryOp_ShiftRight'     => array( 6, -1),
        'Expr_BinaryOp_Smaller'        => array( 7,  0),
        'Expr_BinaryOp_SmallerOrEqual' => array( 7,  0),
        'Expr_BinaryOp_Greater'        => array( 7,  0),
        'Expr_BinaryOp_GreaterOrEqual' => array( 7,  0),
        'Expr_BinaryOp_Equal'          => array( 8,  0),
        'Expr_BinaryOp_NotEqual'       => array( 8,  0),
        'Expr_BinaryOp_Identical'      => array( 8,  0),
        'Expr_BinaryOp_NotIdentical'   => array( 8,  0),
        'Expr_BinaryOp_BitwiseAnd'     => array( 9, -1),
        'Expr_BinaryOp_BitwiseXor'     => array(10, -1),
        'Expr_BinaryOp_BitwiseOr'      => array(11, -1),
        'Expr_BinaryOp_BooleanAnd'     => array(12, -1),
        'Expr_BinaryOp_BooleanOr'      => array(13, -1),
        'Expr_Ternary'                 => array(14, -1),
        // parser uses %left for assignments, but they really behave as %right
        'Expr_Assign'                  => array(15,  1),
        'Expr_AssignRef'               => array(15,  1),
        'Expr_AssignOp_Plus'           => array(15,  1),
        'Expr_AssignOp_Minus'          => array(15,  1),
        'Expr_AssignOp_Mul'            => array(15,  1),
        'Expr_AssignOp_Div'            => array(15,  1),
        'Expr_AssignOp_Concat'         => array(15,  1),
        'Expr_AssignOp_Mod'            => array(15,  1),
        'Expr_AssignOp_BitwiseAnd'     => array(15,  1),
        'Expr_AssignOp_BitwiseOr'      => array(15,  1),
        'Expr_AssignOp_BitwiseXor'     => array(15,  1),
        'Expr_AssignOp_ShiftLeft'      => array(15,  1),
        'Expr_AssignOp_ShiftRight'     => array(15,  1),
        'Expr_AssignOp_Pow'            => array(15,  1),
        'Expr_BinaryOp_LogicalAnd'     => array(16, -1),
        'Expr_BinaryOp_LogicalXor'     => array(17, -1),
        'Expr_BinaryOp_LogicalOr'      => array(18, -1),
        'Expr_Include'                 => array(19, -1),
    );

    protected $noIndentToken;
    protected $canUseSemicolonNamespaces;

    public function __construct() {
        $this->noIndentToken = '_NO_INDENT_' . mt_rand();
    }

    /**
     * Pretty prints an array of statements.
     *
     * @param Node[] $stmts Array of statements
     *
     * @return string Pretty printed statements
     */
    public function prettyPrint(array $stmts) {
        $this->preprocessNodes($stmts);

        return trim(str_replace("\n" . $this->noIndentToken, "\n", $this->pStmts($stmts, false)));
    }

    /**
     * Pretty prints an expression.
     *
     * @param Expr $node Expression node
     *
     * @return string Pretty printed node
     */
    public function prettyPrintExpr(Expr $node) {
        return str_replace("\n" . $this->noIndentToken, "\n", $this->p($node));
    }

    /**
     * Pretty prints a file of statements (includes the opening <?php tag if it is required).
     *
     * @param Node[] $stmts Array of statements
     *
     * @return string Pretty printed statements
     */
    public function prettyPrintFile(array $stmts) {
        $p = $this->prettyPrint($stmts);

        $p = preg_replace('/^\?>\n?/', '', $p, -1, $count);
        $p = preg_replace('/<\?php$/', '', $p);

        if (!$count) {
            $p = "<?php\n\n" . $p;
        }

        return $p;
    }

    /**
     * Preprocesses the top-level nodes to initialize pretty printer state.
     *
     * @param Node[] $nodes Array of nodes
     */
    protected function preprocessNodes(array $nodes) {
        /* We can use semicolon-namespaces unless there is a global namespace declaration */
        $this->canUseSemicolonNamespaces = true;
        foreach ($nodes as $node) {
            if ($node instanceof Stmt\Namespace_ && null === $node->name) {
                $this->canUseSemicolonNamespaces = false;
            }
        }
    }

    /**
     * Pretty prints an array of nodes (statements) and indents them optionally.
     *
     * @param Node[] $nodes  Array of nodes
     * @param bool   $indent Whether to indent the printed nodes
     *
     * @return string Pretty printed statements
     */
    protected function pStmts(array $nodes, $indent = true) {
        $result = '';
        foreach ($nodes as $node) {
            $result .= "\n"
                    . $this->pComments($node->getAttribute('comments', array()))
                    . $this->p($node)
                    . ($node instanceof Expr ? ';' : '');
        }

        if ($indent) {
            return preg_replace('~\n(?!$|' . $this->noIndentToken . ')~', "\n    ", $result);
        } else {
            return $result;
        }
    }

    /**
     * Pretty prints a node.
     *
     * @param Node $node Node to be pretty printed
     *
     * @return string Pretty printed node
     */
    protected function p(Node $node) {
        return $this->{'p' . $node->getType()}($node);
    }

    protected function pInfixOp($type, Node $leftNode, $operatorString, Node $rightNode) {
        list($precedence, $associativity) = $this->precedenceMap[$type];

        return $this->pPrec($leftNode, $precedence, $associativity, -1)
             . $operatorString
             . $this->pPrec($rightNode, $precedence, $associativity, 1);
    }

    protected function pPrefixOp($type, $operatorString, Node $node) {
        list($precedence, $associativity) = $this->precedenceMap[$type];
        return $operatorString . $this->pPrec($node, $precedence, $associativity, 1);
    }

    protected function pPostfixOp($type, Node $node, $operatorString) {
        list($precedence, $associativity) = $this->precedenceMap[$type];
        return $this->pPrec($node, $precedence, $associativity, -1) . $operatorString;
    }

    /**
     * Prints an expression node with the least amount of parentheses necessary to preserve the meaning.
     *
     * @param Node $node                Node to pretty print
     * @param int  $parentPrecedence    Precedence of the parent operator
     * @param int  $parentAssociativity Associativity of parent operator
     *                                  (-1 is left, 0 is nonassoc, 1 is right)
     * @param int  $childPosition       Position of the node relative to the operator
     *                                  (-1 is left, 1 is right)
     *
     * @return string The pretty printed node
     */
    protected function pPrec(Node $node, $parentPrecedence, $parentAssociativity, $childPosition) {
        $type = $node->getType();
        if (isset($this->precedenceMap[$type])) {
            $childPrecedence = $this->precedenceMap[$type][0];
            if ($childPrecedence > $parentPrecedence
                || ($parentPrecedence == $childPrecedence && $parentAssociativity != $childPosition)
            ) {
                return '(' . $this->{'p' . $type}($node) . ')';
            }
        }

        return $this->{'p' . $type}($node);
    }

    /**
     * Pretty prints an array of nodes and implodes the printed values.
     *
     * @param Node[] $nodes Array of Nodes to be printed
     * @param string $glue  Character to implode with
     *
     * @return string Imploded pretty printed nodes
     */
    protected function pImplode(array $nodes, $glue = '') {
        $pNodes = array();
        foreach ($nodes as $node) {
            $pNodes[] = $this->p($node);
        }

        return implode($glue, $pNodes);
    }

    /**
     * Pretty prints an array of nodes and implodes the printed values with commas.
     *
     * @param Node[] $nodes Array of Nodes to be printed
     *
     * @return string Comma separated pretty printed nodes
     */
    protected function pCommaSeparated(array $nodes) {
        return $this->pImplode($nodes, ', ');
    }

    /**
     * Signals the pretty printer that a string shall not be indented.
     *
     * @param string $string Not to be indented string
     *
     * @return mixed String marked with $this->noIndentToken's.
     */
    protected function pNoIndent($string) {
        return str_replace("\n", "\n" . $this->noIndentToken, $string);
    }

    protected function pComments(array $comments) {
        $result = '';

        foreach ($comments as $comment) {
            $result .= $comment->getReformattedText() . "\n";
        }

        return $result;
    }
}