/**
 * ESLint rule to enforce View Model Builder contract
 * 
 * View Model Builders must:
 * 1. Be classes named *ViewModelBuilder
 * 2. Have a static build() method
 * 3. Accept View Data as parameter
 * 4. Return View Model
 */

module.exports = {
  meta: {
    type: 'problem',
    docs: {
      description: 'Enforce View Model Builder contract',
      category: 'Builders',
      recommended: true,
    },
    fixable: null,
    schema: [],
    messages: {
      notAClass: 'View Model Builders must be classes named *ViewModelBuilder',
      missingBuildMethod: 'View Model Builders must have a static build() method',
      invalidBuildSignature: 'build() method must accept View Data and return View Model',
    },
  },

  create(context) {
    const filename = context.getFilename();
    const isInViewModelBuilders = filename.includes('/lib/builders/view-models/');
    
    if (!isInViewModelBuilders) return {};

    let hasBuildMethod = false;
    let hasCorrectSignature = false;

    return {
      // Check class declaration
      ClassDeclaration(node) {
        const className = node.id?.name;
        
        if (!className || !className.endsWith('ViewModelBuilder')) {
          context.report({
            node,
            messageId: 'notAClass',
          });
        }

        // Check for static build method
        const buildMethod = node.body.body.find(member => 
          member.type === 'MethodDefinition' &&
          member.key.type === 'Identifier' &&
          member.key.name === 'build' &&
          member.static === true
        );

        if (buildMethod) {
          hasBuildMethod = true;
          
          // Check signature - should have at least one parameter
          if (buildMethod.value && 
              buildMethod.value.params && 
              buildMethod.value.params.length > 0) {
            hasCorrectSignature = true;
          }
        }
      },

      'Program:exit'() {
        if (!hasBuildMethod) {
          context.report({
            node: context.getSourceCode().ast,
            messageId: 'missingBuildMethod',
          });
        } else if (!hasCorrectSignature) {
          context.report({
            node: context.getSourceCode().ast,
            messageId: 'invalidBuildSignature',
          });
        }
      },
    };
  },
};
