/**
 * ESLint rule to enforce View Data Builder contract
 *
 * View Data Builders must:
 * 1. Be classes named *ViewDataBuilder
 * 2. Have a static build() method
 * 3. Accept API DTO as parameter (named 'apiDto', NOT 'pageDto')
 * 4. Return View Data
 */

module.exports = {
  meta: {
    type: 'problem',
    docs: {
      description: 'Enforce View Data Builder contract',
      category: 'Builders',
      recommended: true,
    },
    fixable: null,
    schema: [],
    messages: {
      notAClass: 'View Data Builders must be classes named *ViewDataBuilder',
      missingBuildMethod: 'View Data Builders must have a static build() method',
      invalidBuildSignature: 'build() method must accept API DTO and return View Data',
      wrongParameterName: 'Parameter must be named "apiDto", not "pageDto" or other names',
    },
  },

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

    let hasBuildMethod = false;
    let hasCorrectSignature = false;
    let hasCorrectParameterName = false;

    return {
      // Check class declaration
      ClassDeclaration(node) {
        const className = node.id?.name;
        
        if (!className || !className.endsWith('ViewDataBuilder')) {
          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;
            
            // Check parameter name
            const firstParam = buildMethod.value.params[0];
            if (firstParam.type === 'Identifier' && firstParam.name === 'apiDto') {
              hasCorrectParameterName = true;
            } else if (firstParam.type === 'Identifier' && firstParam.name === 'pageDto') {
              // Report specific error for pageDto
              context.report({
                node: firstParam,
                messageId: 'wrongParameterName',
              });
            }
          }
        }
      },

      'Program:exit'() {
        if (!hasBuildMethod) {
          context.report({
            node: context.getSourceCode().ast,
            messageId: 'missingBuildMethod',
          });
        } else if (!hasCorrectSignature) {
          context.report({
            node: context.getSourceCode().ast,
            messageId: 'invalidBuildSignature',
          });
        } else if (!hasCorrectParameterName) {
          // Only report if not already reported for pageDto
          context.report({
            node: context.getSourceCode().ast,
            messageId: 'wrongParameterName',
          });
        }
      },
    };
  },
};
