<?php

namespace Knuckles\Scribe\Extracting\Strategies;

use Knuckles\Camel\Extraction\ExtractedEndpointData;
use Knuckles\Scribe\Extracting\MethodAstParser;
use Knuckles\Scribe\Extracting\ParsesValidationRules;
use PhpParser\Node;
use PhpParser\Node\Stmt\ClassMethod;

class GetFromInlineValidatorBase extends Strategy
{
    use ParsesValidationRules;

    public function __invoke(ExtractedEndpointData $endpointData, array $routeRules): ?array
    {
        if (!$endpointData->method instanceof \ReflectionMethod) {
            return [];
        }

        $methodAst = MethodAstParser::getMethodAst($endpointData->method);
        [$validationRules, $customParameterData] = $this->lookForInlineValidationRules($methodAst);

        $bodyParametersFromValidationRules = $this->getParametersFromValidationRules($validationRules, $customParameterData);
        return $this->normaliseArrayAndObjectParameters($bodyParametersFromValidationRules);
    }

    public function lookForInlineValidationRules(ClassMethod $methodAst): array
    {
        // Validation usually happens early on, so let's assume it's in the first 6 statements
        $statements = array_slice($methodAst->stmts, 0, 6);

        $validationRules = null;
        $validationAssignmentExpression = null;
        $index = null;
        foreach ($statements as $index => $node) {
            // Filter to only assignment expressions
            if (!($node instanceof Node\Stmt\Expression) || !($node->expr instanceof Node\Expr\Assign)) {
                continue;
            }

            $validationAssignmentExpression = $node->expr;
            $rvalue = $validationAssignmentExpression->expr;

            // Look for $validated = $request->validate(...)
            if (
                $rvalue instanceof Node\Expr\MethodCall && $rvalue->var instanceof Node\Expr\Variable
                && in_array($rvalue->var->name, ["request", "req"]) && $rvalue->name->name == "validate"
            ) {
                $validationRules = $rvalue->args[0]->value;
                break;
            } else if (
                // Try $validator = Validator::make(...)
                $rvalue instanceof Node\Expr\StaticCall && $rvalue->class->parts && end($rvalue->class->parts) == "Validator"
                && $rvalue->name->name == "make"
            ) {
                $validationRules = $rvalue->args[1]->value;
                break;
            }
        }

        if ($validationAssignmentExpression && !$this->isAssignmentMeantForThisStrategy($validationAssignmentExpression)) {
            return [[], []];
        }

        // If validation rules were saved in a variable (like $rules),
        // find the var and expand the value
        if ($validationRules instanceof Node\Expr\Variable) {
            foreach (array_reverse(array_slice($statements, 0, $index)) as $earlierStatement) {
                if (
                    $earlierStatement instanceof Node\Stmt\Expression
                    && $earlierStatement->expr instanceof Node\Expr\Assign
                    && $earlierStatement->expr->var instanceof Node\Expr\Variable
                    && $earlierStatement->expr->var->name == $validationRules->name
                ) {
                    $validationRules = $earlierStatement->expr->expr;
                    break;
                }
            }
        }

        if (!$validationRules instanceof Node\Expr\Array_) {
            return [[], []];
        }

        $rules = [];
        $customParameterData = [];
        foreach ($validationRules->items as $item) {
            /** @var Node\Expr\ArrayItem $item */
            if (!$item->key instanceof Node\Scalar\String_) {
                continue;
            }

            $paramName = $item->key->value;

            // Might be an expression or concatenated string, etc.
            // For now, let's focus on simple strings and arrays of strings
            if ($item->value instanceof Node\Scalar\String_) {
                $rules[$paramName] = $item->value->value;
            } else if ($item->value instanceof Node\Expr\Array_) {
                $rulesList = [];
                foreach ($item->value->items as $arrayItem) {
                    /** @var Node\Expr\ArrayItem $arrayItem */
                    if ($arrayItem->value instanceof Node\Scalar\String_) {
                        $rulesList[] = $arrayItem->value->value;
                    }

                }
                $rules[$paramName] = join('|', $rulesList);
            } else {
                $rules[$paramName] = [];
                continue;
            }

            $description = $example = null;
            $comments = join("\n", array_map(
                    fn($comment) => ltrim(ltrim($comment->getReformattedText(), "/")),
                    $item->getComments()
                )
            );

            if ($comments) {
                $description = trim(str_replace(['No-example.', 'No-example'], '', $comments));
                $example = null;
                if (preg_match('/(.*\s+|^)Example:\s*([\s\S]+)\s*/m', $description, $matches)) {
                    $description = trim($matches[1]);
                    $example = $matches[2];
                }
            }

            $customParameterData[$paramName] = compact('description', 'example');
        }

        return [$rules, $customParameterData];
    }

    protected function getMissingCustomDataMessage($parameterName)
    {
        return "No extra data found for parameter '$parameterName' from your inline validator. You can add a comment above '$parameterName' with a description and example.";
    }

    protected function shouldCastUserExample()
    {
        return true;
    }

    protected function isAssignmentMeantForThisStrategy(Node\Expr\Assign $validationAssignmentExpression): bool
    {
        return true;
    }
}