import chalk from 'chalk';
import { TopLevelDirectoryName, TopLevelFileName, WorkflowsDirectoryName } from '../domain/file-names';
import { CLIProductModuleDefinition } from '../domain/product-module-definition';

type ListName = 'alterationHooks' | 'applicationAlterationHooks' | 'memberAlterationHooks';

const formatLocations = (locations: ListName[]): string => {
  const counts = new Map<ListName, number>();
  for (const loc of locations) {
    counts.set(loc, (counts.get(loc) ?? 0) + 1);
  }
  return Array.from(counts.entries())
    .map(([list, n]) => (n === 1 ? list : `${list} ×${n}`))
    .join(', ');
};

export const validateAlterationHookKeys = (definition: CLIProductModuleDefinition): void => {
  const occurrences = new Map<string, ListName[]>();

  const record = (listName: ListName, key: string) => {
    const existing = occurrences.get(key) ?? [];
    existing.push(listName);
    occurrences.set(key, existing);
  };

  for (const hook of definition.workflows.alterationHooks) {
    record('alterationHooks', hook.key);
  }
  for (const hook of definition.workflows.applicationAlterationHooks) {
    record('applicationAlterationHooks', hook.key);
  }
  for (const hook of definition.workflows.memberAlterationHooks || []) {
    record('memberAlterationHooks', hook.key);
  }

  const lines: string[] = [];
  for (const [key, locations] of occurrences) {
    if (locations.length <= 1) continue;
    const quotedKey = `"${key}"`;
    lines.push(`  • ${chalk.yellow(quotedKey)} — ${formatLocations(locations)}`);
  }

  if (lines.length === 0) return;

  const configFile = TopLevelFileName.RootConfig;
  const alterationHooksDir = `${TopLevelDirectoryName.Workflows}/${WorkflowsDirectoryName.AlterationHooks}/`;
  const applicationAlterationHooksDir = `${TopLevelDirectoryName.Workflows}/${WorkflowsDirectoryName.ApplicationAlterationHooks}/`;
  const memberAlterationHooksDir = `${TopLevelDirectoryName.Workflows}/${WorkflowsDirectoryName.MemberAlterationHooks}/`;

  throw new Error(
    [
      'Duplicate alteration hook keys found',
      `Source: ${chalk.yellow(configFile)}`,
      '',
      'Conflicting keys:',
      ...lines,
      '',
      `Tip: rename one occurrence of each conflicting key in ${chalk.yellow(configFile)} and rename the`,
      `matching file under ${chalk.yellow(alterationHooksDir)}, ${chalk.yellow(
        applicationAlterationHooksDir,
      )} or ${chalk.yellow(
        memberAlterationHooksDir,
      )} to match. Each alteration hook key must be unique across the product module.`,
    ].join('\n'),
  );
};