/**
 * Zod schemas for every structured LLM output the platform consumes.
 *
 * Field names mirror what callers already produce — do not rename them
 * without migrating the corresponding service module.
 */

import { z } from 'zod';

const topicTypeEnum = z.enum(['concept', 'role', 'process']);
const relationTypeStrict = z.enum(['related_to', 'depends_on', 'part_of', 'executed_by']);
const relationTypeLoose = z.enum(['related_to', 'depends_on', 'part_of', 'executed_by', 'executes']);
const learningRelevanceEnum = z.enum(['core', 'standard', 'peripheral', 'exclude']);

const extractionTopicSchema = z.object({
  id: z.string().min(1),
  label: z.string().min(1),
  type: topicTypeEnum,
  description: z.string().min(1),
  learning_relevance: learningRelevanceEnum,
});

const extractionRelationSchema = z.object({
  source: z.string().min(1),
  target: z.string().min(1),
  type: relationTypeStrict,
});

export const extractionResultSchema = z.object({
  topics: z.array(extractionTopicSchema),
  relations: z.array(extractionRelationSchema),
});

const handbookTopicSchema = extractionTopicSchema.extend({
  metadata: z.object({ source: z.string() }).optional(),
});

const handbookRelationSchema = z.object({
  source: z.string().min(1),
  target: z.string().min(1),
  type: relationTypeLoose,
  description: z.string().optional(),
});

export const handbookResultSchema = z.object({
  topics: z.array(handbookTopicSchema),
  relations: z.array(handbookRelationSchema),
});

/**
 * Normalise legacy `executes` relations into the canonical `executed_by`
 * vocabulary by swapping source and target. The handbook prompt previously
 * emitted `role → executes → process`; the canonical form is
 * `process → executed_by → role`.
 */
export function normalizeHandbookResult(parsed) {
  return {
    ...parsed,
    relations: parsed.relations.map((r) =>
      r.type === 'executes'
        ? { ...r, type: 'executed_by', source: r.target, target: r.source }
        : r,
    ),
  };
}

const articleSectionSchema = z.object({
  heading: z.string().min(1),
  body: z.string().min(1),
});

const articleBodySchema = z.object({
  title: z.string().min(1),
  intro: z.string().min(1),
  sections: z.array(articleSectionSchema).min(1),
  keyTakeaways: z.array(z.string().min(1)).min(1),
});

export const learningArticleSchema = z.object({
  article: articleBodySchema,
});

const slideSchema = z.object({
  title: z.string().min(1),
  bullets: z.array(z.string().min(1)).min(1),
  speakerNote: z.string().min(1),
});

export const learningSlidesSchema = z.object({
  slides: z.array(slideSchema).min(1),
});

const infographicStatSchema = z.object({
  value: z.string().min(1),
  label: z.string().min(1),
  icon: z.string().min(1),
});

const infographicStepSchema = z.object({
  number: z.number().int().min(1),
  title: z.string().min(1),
  description: z.string().min(1),
  icon: z.string().min(1),
});

const infographicBodySchema = z.object({
  headline: z.string().min(1),
  tagline: z.string().min(1),
  stats: z.array(infographicStatSchema).min(1),
  steps: z.array(infographicStepSchema).min(1),
  quote: z.string().min(1),
  colorTheme: z.string().min(1),
});

export const learningInfographicSchema = z.object({
  infographic: infographicBodySchema,
});

export const learningAllSchema = z.object({
  article: articleBodySchema,
  slides: z.array(slideSchema).min(1),
  infographic: infographicBodySchema,
});

const quizDifficultyEnum = z.enum(['easy', 'medium', 'hard']);

const quizQuestionSchema = z.object({
  id: z.string().min(1),
  question: z.string().min(1),
  topicLabel: z.string().min(1),
  options: z.array(z.string().min(1)).length(4),
  correctIndex: z.number().int().min(0).max(3),
  explanation: z.string().min(1),
  difficulty: quizDifficultyEnum,
});

export const quizQuestionsSchema = z.object({
  questions: z.array(quizQuestionSchema).min(1),
});

export const customTopicSchema = z.object({
  label: z.string().min(1),
  type: topicTypeEnum,
  description: z.string().min(1),
});

const mergeActionSchema = z.object({
  keepId: z.string().min(1),
  deleteId: z.string().min(1),
});

const newRelationSchema = z.object({
  source: z.string().min(1),
  target: z.string().min(1),
  type: relationTypeStrict,
});

const relevanceUpdateSchema = z.object({
  id: z.string().min(1),
  learning_relevance: learningRelevanceEnum,
});

export const graphActionsSchema = z.object({
  merges: z.array(mergeActionSchema).optional().default([]),
  deletions: z.array(z.string().min(1)).optional().default([]),
  newRelations: z.array(newRelationSchema).optional().default([]),
  relevanceUpdates: z.array(relevanceUpdateSchema).optional().default([]),
});

const deltaTopicSchema = z.object({
  id: z.string().min(1),
  label: z.string().min(1),
  type: topicTypeEnum,
  description: z.string().min(1),
});

const deltaRelationSchema = z.object({
  source: z.string().min(1),
  target: z.string().min(1),
  type: relationTypeStrict,
});

export const proposeGraphDeltaSchema = z.object({
  reason: z.string().min(1),
  topics: z.array(deltaTopicSchema).max(3).optional(),
  relations: z.array(deltaRelationSchema).max(5).optional(),
});

// ── Article patch operation schemas (Phase 2.4) ──────────────────────────────

export const setIntroPatchSchema = z.object({
  intro: z.string().min(1),
});

export const setSectionPatchSchema = z.object({
  heading: z.string().min(1),
  body: z.string().min(1),
});

export const addSectionPatchSchema = z.object({
  heading: z.string().min(1),
  body: z.string().min(1),
  position: z.enum(['start', 'end']),
});

export const removeSectionPatchSchema = z.object({
  heading: z.string().min(1),
});

export const replaceTakeawaysPatchSchema = z.object({
  items: z.array(z.string().min(1)).min(1),
});

/**
 * Registry mapping known tool names to their input schemas. `callLLM`
 * consults this when the caller does not pass an explicit `toolSchemas`
 * override.
 */
export const toolSchemaRegistry = {
  emit_knowledge_graph: extractionResultSchema,
  emit_handbook_delta: handbookResultSchema,
  emit_learning_article: learningArticleSchema,
  emit_learning_slides: learningSlidesSchema,
  emit_learning_infographic: learningInfographicSchema,
  emit_learning_all: learningAllSchema,
  emit_quiz_questions: quizQuestionsSchema,
  emit_custom_topic: customTopicSchema,
  emit_graph_actions: graphActionsSchema,
  propose_graph_delta: proposeGraphDeltaSchema,
  set_intro: setIntroPatchSchema,
  set_section: setSectionPatchSchema,
  add_section: addSectionPatchSchema,
  remove_section: removeSectionPatchSchema,
  replace_takeaways: replaceTakeawaysPatchSchema,
};