/**
 * Markdown renderer for interview profiles.
 * Converts collected answers into markdown output based on profile configuration.
 * WP-26: Erweitert um Section-Types, Block-IDs und automatische Edge-Vorschläge.
 */

import type { InterviewProfile, InterviewStep, CaptureTextStep, CaptureTextLineStep, CaptureFrontmatterStep, LoopStep, EntityPickerStep } from "./types";
import type { SectionInfo } from "./wizardState";
import type { GraphSchema } from "../mapping/graphSchema";
import type { Vocabulary } from "../vocab/Vocabulary";
import { slugify } from "./slugify";
import { getHints } from "../mapping/graphSchema";

export interface RenderAnswers {
  collectedData: Map<string, unknown>;
  loopContexts: Map<string, unknown[]>;
  // WP-26: Optional - Section-Sequenz für automatische Edge-Vorschläge
  sectionSequence?: SectionInfo[];
}

// WP-26: Render-Optionen für Section-Types und Edge-Vorschläge
export interface RenderOptions {
  graphSchema?: GraphSchema | null;
  vocabulary?: Vocabulary | null;
  noteType?: string; // Fallback für effective_type
}

/**
 * Render profile answers to markdown string.
 * Deterministic and testable.
 * WP-26: Erweitert um Section-Types, Block-IDs und automatische Edge-Vorschläge.
 */
export function renderProfileToMarkdown(
  profile: InterviewProfile,
  answers: RenderAnswers,
  options?: RenderOptions
): string {
  const output: string[] = [];
  
  // WP-26: Verwende übergebene Section-Sequenz oder erstelle neue
  // Die Section-Sequenz wird während des interaktiven Wizard-Durchlaufs getrackt
  const sectionSequence: SectionInfo[] = answers.sectionSequence ? [...answers.sectionSequence] : [];
  const generatedBlockIds = new Map<string, SectionInfo>();
  
  // WP-26: Wenn Section-Sequenz übergeben wurde, fülle generatedBlockIds aus der Sequenz
  if (answers.sectionSequence && answers.sectionSequence.length > 0) {
    for (const sectionInfo of answers.sectionSequence) {
      if (sectionInfo.blockId) {
        generatedBlockIds.set(sectionInfo.blockId, sectionInfo);
      }
    }
  }
  
  // WP-26: Track Section-Sequenz während des Renderns (für Steps, die noch nicht getrackt wurden)
  for (const step of profile.steps) {
    const stepOutput = renderStep(
      step, 
      answers, 
      {
        profile,
        sectionSequence,
        generatedBlockIds,
        options: options || {},
      }
    );
    if (stepOutput) {
      output.push(stepOutput);
    }
  }
  
  return output.join("\n\n").trim();
}

// WP-26: Render-Kontext für Section-Types und Block-IDs
interface RenderContext {
  profile: InterviewProfile;
  sectionSequence: SectionInfo[];
  generatedBlockIds: Map<string, SectionInfo>;
  options: RenderOptions;
}

/**
 * Render a single step to markdown.
 * WP-26: Erweitert um RenderContext für Section-Types und Block-IDs.
 */
function renderStep(
  step: InterviewStep, 
  answers: RenderAnswers, 
  context: RenderContext
): string | null {
  switch (step.type) {
    case "capture_text":
      return renderCaptureText(step, answers, context);
    case "capture_text_line":
      return renderCaptureTextLine(step, answers, context);
    case "capture_frontmatter":
      // Frontmatter is handled separately, skip here
      return null;
    case "loop":
      return renderLoop(step, answers, context);
    case "entity_picker":
      return renderEntityPicker(step, answers);
    case "instruction":
    case "llm_dialog":
    case "review":
      // These don't produce markdown output
      return null;
    default:
      return null;
  }
}

/**
 * Render capture_text step.
 * WP-26: Erweitert um Section-Types, Block-IDs und Edge-Vorschläge.
 */
function renderCaptureText(
  step: CaptureTextStep, 
  answers: RenderAnswers, 
  context: RenderContext
): string | null {
  const value = answers.collectedData.get(step.key);
  if (!value || String(value).trim() === "") {
    return null;
  }
  
  const text = String(value);
  
  // WP-26: Block-ID-Generierung
  let blockId: string | null = null;
  if (step.block_id) {
    blockId = step.block_id;
  } else if (step.generate_block_id) {
    blockId = slugify(step.key);
  }
  
  // WP-26: Heading mit Block-ID erweitern
  let heading = step.section || "";
  if (heading && blockId) {
    // Füge Block-ID zu Heading hinzu: "## Heading" -> "## Heading ^block-id"
    heading = heading.replace(/^(\s*#{1,6}\s+)(.+)$/, `$1$2 ^${blockId}`);
  }
  
  // WP-26: Section-Type-Callout generieren (direkt nach Heading)
  const sectionTypeCallout = step.section_type 
    ? `> [!section] ${step.section_type}` 
    : "";
  
  // WP-26: Section-Info für Tracking
  const sectionInfo: SectionInfo = {
    stepKey: step.key,
    sectionType: step.section_type || null,
    heading: heading || step.key,
    blockId: blockId,
    noteType: context.options.noteType || context.profile.note_type,
  };
  
  // WP-26: Block-ID tracken
  if (blockId) {
    context.generatedBlockIds.set(blockId, sectionInfo);
  }
  
  // WP-26: Section-Sequenz aktualisieren (nur wenn Section vorhanden)
  if (step.section) {
    context.sectionSequence.push(sectionInfo);
  }
  
  // WP-26: Referenzen generieren (am Ende der Sektion)
  const references = renderReferences(step.references || [], context, sectionInfo);
  
  // WP-26: Automatische Edge-Vorschläge generieren (am Ende der Sektion)
  const autoEdges = renderAutomaticEdges(sectionInfo, context);
  
  // Use template if provided
  if (step.output?.template) {
    const templateText = renderTemplate(step.output.template, {
      text,
      field: step.key,
      value: text,
    });
    
    // WP-26: Template mit Heading, Section-Type und Edges kombinieren
    return combineSectionParts(heading, sectionTypeCallout, templateText, references, autoEdges);
  }
  
  // Default: use section if provided, otherwise just the text
  if (step.section) {
    return combineSectionParts(heading, sectionTypeCallout, text, references, autoEdges);
  }
  
  return text;
}

/**
 * Render capture_text_line step.
 * WP-26: Erweitert um Section-Types, Block-IDs und Edge-Vorschläge.
 */
function renderCaptureTextLine(
  step: CaptureTextLineStep, 
  answers: RenderAnswers, 
  context: RenderContext
): string | null {
  const value = answers.collectedData.get(step.key);
  if (!value || String(value).trim() === "") {
    return null;
  }
  
  const text = String(value);
  
  // Get heading level if configured
  const headingLevelKey = `${step.key}_heading_level`;
  const headingLevel = answers.collectedData.get(headingLevelKey);
  let headingPrefix = "";
  if (step.heading_level?.enabled) {
    if (typeof headingLevel === "number") {
      const level = Math.max(1, Math.min(6, headingLevel));
      headingPrefix = "#".repeat(level) + " ";
    } else if (step.heading_level.default) {
      // Fallback to default if not set
      const level = Math.max(1, Math.min(6, step.heading_level.default));
      headingPrefix = "#".repeat(level) + " ";
    }
  }
  
  // WP-26: Block-ID-Generierung
  let blockId: string | null = null;
  if (step.block_id) {
    blockId = step.block_id;
  } else if (step.generate_block_id) {
    blockId = slugify(step.key);
  }
  
  // WP-26: Heading mit Block-ID erweitern (wenn heading_prefix vorhanden)
  let heading = "";
  if (headingPrefix) {
    heading = headingPrefix + text;
    if (blockId) {
      // Füge Block-ID zu Heading hinzu
      heading = heading.replace(/^(\s*#{1,6}\s+)(.+)$/, `$1$2 ^${blockId}`);
    }
  }
  
  // WP-26: Section-Type-Callout generieren (direkt nach Heading)
  const sectionTypeCallout = step.section_type 
    ? `> [!section] ${step.section_type}` 
    : "";
  
  // WP-26: Section-Info für Tracking (nur wenn Heading vorhanden)
  if (headingPrefix) {
    const sectionInfo: SectionInfo = {
      stepKey: step.key,
      sectionType: step.section_type || null,
      heading: heading || text,
      blockId: blockId,
      noteType: context.options.noteType || context.profile.note_type,
    };
    
    // WP-26: Block-ID tracken
    if (blockId) {
      context.generatedBlockIds.set(blockId, sectionInfo);
    }
    
    // WP-26: Section-Sequenz aktualisieren
    context.sectionSequence.push(sectionInfo);
  }
  
  // WP-26: Section-Info für Tracking (nur wenn Heading vorhanden)
  let sectionInfo: SectionInfo | null = null;
  if (headingPrefix) {
    sectionInfo = {
      stepKey: step.key,
      sectionType: step.section_type || null,
      heading: heading || text,
      blockId: blockId,
      noteType: context.options.noteType || context.profile.note_type,
    };
    
    // WP-26: Block-ID tracken
    if (blockId) {
      context.generatedBlockIds.set(blockId, sectionInfo);
    }
    
    // WP-26: Section-Sequenz aktualisieren
    context.sectionSequence.push(sectionInfo);
  }
  
  // WP-26: Referenzen generieren (am Ende der Sektion)
  const references = sectionInfo 
    ? renderReferences(step.references || [], context, sectionInfo)
    : "";
  
  // WP-26: Automatische Edge-Vorschläge generieren (nur wenn Heading vorhanden)
  const autoEdges = sectionInfo 
    ? renderAutomaticEdges(sectionInfo, context)
    : "";
  
  // Use template if provided
  if (step.output?.template) {
    const templateText = renderTemplate(step.output.template, {
      text: headingPrefix + text,
      field: step.key,
      value: headingPrefix + text,
      heading_level: headingLevel ? String(headingLevel) : "",
    });
    
    // WP-26: Template mit Heading, Section-Type und Edges kombinieren (wenn Heading vorhanden)
    if (headingPrefix) {
      return combineSectionParts(heading, sectionTypeCallout, "", references, autoEdges);
    }
    
    return templateText;
  }
  
  // WP-26: Wenn Heading vorhanden, mit Section-Type und Edges kombinieren
  if (headingPrefix) {
    return combineSectionParts(heading, sectionTypeCallout, "", references, autoEdges);
  }
  
  // Default: text with heading prefix if configured
  return headingPrefix + text;
}

/**
 * Render entity_picker step.
 */
function renderEntityPicker(step: EntityPickerStep, answers: RenderAnswers): string | null {
  const basename = answers.collectedData.get(step.key);
  if (!basename || typeof basename !== "string" || !basename.trim()) {
    return null;
  }
  
  // Check if there's a label field
  let label: string | undefined;
  if (step.labelField) {
    const labelValue = answers.collectedData.get(step.labelField);
    if (labelValue && typeof labelValue === "string" && labelValue.trim()) {
      label = labelValue.trim();
    }
  }
  
  // Render wikilink
  if (label) {
    return `[[${basename}|${label}]]`;
  } else {
    return `[[${basename}]]`;
  }
}

/**
 * Render capture_frontmatter step.
 * Note: This is typically handled separately, but included for completeness.
 */
function renderCaptureFrontmatter(step: CaptureFrontmatterStep, answers: RenderAnswers): string | null {
  const value = answers.collectedData.get(step.key);
  if (value === undefined || value === null || String(value).trim() === "") {
    return null;
  }
  
  // Use template if provided
  if (step.output?.template) {
    return renderTemplate(step.output.template, {
      text: String(value),
      field: step.field,
      value: String(value),
    });
  }
  
  // Default: no markdown output (frontmatter is handled separately)
  return null;
}

/**
 * Render loop step (recursive, supports arbitrary nesting depth).
 * WP-26: Erweitert um RenderContext für Section-Types und Block-IDs.
 */
function renderLoop(step: LoopStep, answers: RenderAnswers, context: RenderContext): string | null {
  return renderLoopRecursive(step, answers, context, 0);
}

/**
 * Recursive helper to render loop items with nested steps.
 * Supports arbitrary nesting depth (no hard limit, but practical limits apply due to stack size).
 * WP-26: Erweitert um RenderContext für Section-Types und Block-IDs.
 */
function renderLoopRecursive(
  step: LoopStep, 
  answers: RenderAnswers, 
  context: RenderContext,
  depth: number
): string | null {
  // Safety check: prevent infinite recursion (practical limit: 100 levels)
  if (depth > 100) {
    console.warn(`Loop nesting depth ${depth} exceeds practical limit, stopping recursion`);
    return null;
  }
  
  const items = answers.loopContexts.get(step.key);
  if (!items || items.length === 0) {
    return null;
  }
  
  const itemOutputs: string[] = [];
  
  for (const item of items) {
    if (!item || typeof item !== "object") {
      continue;
    }
    
    const itemParts: string[] = [];
    
    // Render each nested step for this item (recursively)
    for (const nestedStep of step.items) {
      const fieldValue = (item as Record<string, unknown>)[nestedStep.key];
      
      if (nestedStep.type === "capture_text") {
        if (fieldValue && String(fieldValue).trim()) {
          const text = String(fieldValue);
          const captureStep = nestedStep as CaptureTextStep;
          
          // WP-26: Verwende erweiterte renderCaptureText Funktion
          const rendered = renderCaptureText(captureStep, {
            collectedData: new Map([[nestedStep.key, fieldValue]]),
            loopContexts: answers.loopContexts,
          }, context);
          
          if (rendered) {
            itemParts.push(rendered);
          }
        }
      } else if (nestedStep.type === "capture_text_line") {
        if (fieldValue && String(fieldValue).trim()) {
          const captureStep = nestedStep as CaptureTextLineStep;
          
          // WP-26: Erstelle temporäres collectedData mit allen Item-Daten
          const itemData = new Map<string, unknown>();
          itemData.set(nestedStep.key, fieldValue);
          
          // Füge heading_level hinzu falls vorhanden
          const headingLevelKey = `${nestedStep.key}_heading_level`;
          const headingLevel = (item as Record<string, unknown>)[headingLevelKey];
          if (headingLevel !== undefined) {
            itemData.set(headingLevelKey, headingLevel);
          }
          
          // WP-26: Verwende erweiterte renderCaptureTextLine Funktion
          const rendered = renderCaptureTextLine(captureStep, {
            collectedData: itemData,
            loopContexts: answers.loopContexts,
          }, context);
          
          if (rendered) {
            itemParts.push(rendered);
          }
        }
      } else if (nestedStep.type === "capture_frontmatter") {
        if (fieldValue && String(fieldValue).trim()) {
          const captureStep = nestedStep as CaptureFrontmatterStep;
          
          // Use template if provided
          if (captureStep.output?.template) {
            itemParts.push(renderTemplate(captureStep.output.template, {
              text: String(fieldValue),
              field: captureStep.field,
              value: String(fieldValue),
            }));
          }
        }
      } else if (nestedStep.type === "loop") {
        // Recursively handle nested loop: fieldValue should be an array of items
        if (Array.isArray(fieldValue) && fieldValue.length > 0) {
          const nestedLoopStep = nestedStep as LoopStep;
          
          // Create a temporary answers object for the nested loop
          // The nested loop items are stored in fieldValue, so we need to create
          // a temporary loopContexts map for the nested loop
          const nestedAnswers: RenderAnswers = {
            collectedData: answers.collectedData,
            loopContexts: new Map(answers.loopContexts),
          };
          nestedAnswers.loopContexts.set(nestedLoopStep.key, fieldValue);
          
          // Recursively render the nested loop
          const nestedOutput = renderLoopRecursive(nestedLoopStep, nestedAnswers, context, depth + 1);
          if (nestedOutput) {
            itemParts.push(nestedOutput);
          }
        }
      }
    }
    
    if (itemParts.length > 0) {
      itemOutputs.push(itemParts.join("\n\n"));
    }
  }
  
  if (itemOutputs.length === 0) {
    return null;
  }
  
  // Check if first nested step has a section header (for backwards compatibility)
  const firstNestedStep = step.items[0];
  let sectionHeader: string | null = null;
  if (firstNestedStep && firstNestedStep.type === "capture_text" && firstNestedStep.section) {
    sectionHeader = firstNestedStep.section;
  }
  
  // Join items with configured separator or default newline
  const joinStr = step.output?.join || "\n\n";
  const loopContent = itemOutputs.join(joinStr);
  
  // Prepend section header if available
  if (sectionHeader) {
    return `${sectionHeader}\n\n${loopContent}`;
  }
  
  return loopContent;
}

/**
 * Render template string with token replacement.
 * Tokens: {text}, {field}, {value}
 */
function renderTemplate(template: string, tokens: { text: string; field: string; value: string; heading_level?: string }): string {
  let result = template
    .replace(/\{text\}/g, tokens.text)
    .replace(/\{field\}/g, tokens.field)
    .replace(/\{value\}/g, tokens.value);
  
  if (tokens.heading_level !== undefined) {
    result = result.replace(/\{heading_level\}/g, tokens.heading_level);
  }
  
  return result;
}

// WP-26: Helper-Funktionen für Section-Types und Block-IDs

/**
 * Kombiniert Heading, Section-Type-Callout, Content und Edges zu einer Section.
 * Formatierungsregel: Section-Type direkt nach Heading, Edges am Ende.
 */
function combineSectionParts(
  heading: string,
  sectionTypeCallout: string,
  content: string,
  references: string,
  autoEdges: string
): string {
  const parts: string[] = [];
  
  if (heading) {
    parts.push(heading);
  }
  
  if (sectionTypeCallout) {
    parts.push(sectionTypeCallout);
  }
  
  if (content) {
    parts.push(content);
  }
  
  // WP-26: Edges am Ende der Sektion (Referenzen + automatische Edges)
  const edges = [references, autoEdges].filter(e => e.trim()).join("\n");
  if (edges) {
    parts.push(edges);
  }
  
  return parts.join("\n\n");
}

/**
 * Generiert Edge-Callouts für explizite Referenzen.
 * Format: > [!edge] <edge_type>\n> [[#^block-id]]
 */
function renderReferences(
  references: Array<{ block_id: string; edge_type?: string }>,
  context: RenderContext,
  currentSection: SectionInfo
): string {
  if (!references || references.length === 0) {
    return "";
  }
  
  const edgeCallouts: string[] = [];
  
  for (const ref of references) {
    // Prüfe, ob Block-ID existiert
    if (!context.generatedBlockIds.has(ref.block_id)) {
      console.warn(`[WP-26] Block-ID "${ref.block_id}" nicht gefunden für Referenz`);
      continue;
    }
    
    // WP-26: Prüfe auf Selbstreferenz
    if (ref.block_id === currentSection.blockId) {
      console.warn(`[WP-26] Selbstreferenz verhindert: Block-ID "${ref.block_id}" zeigt auf sich selbst`);
      continue;
    }
    
    const edgeType = ref.edge_type || "related_to";
    edgeCallouts.push(`> [!edge] ${edgeType}`);
    edgeCallouts.push(`> [[#^${ref.block_id}]]`);
  }
  
  return edgeCallouts.join("\n");
}

/**
 * Generiert automatische Edge-Vorschläge zwischen Sections.
 * Verwendet graph_schema.md für typische Edge-Types und edge_vocabulary.md für inverse Edges.
 * 
 * Formatierungsregel: Edges werden am Ende der aktuellen Section eingefügt.
 * Forward-Edge: prevSection -> currentSection (in aktueller Section)
 * Rückwärts-Edge: currentSection -> prevSection (in aktueller Section, inverser Edge-Type)
 */
function renderAutomaticEdges(
  currentSection: SectionInfo,
  context: RenderContext
): string {
  // Nur wenn aktuelle Section eine Block-ID hat
  if (!currentSection.blockId) {
    return "";
  }
  
  // Nur wenn es vorherige Sections gibt
  if (context.sectionSequence.length <= 1) {
    return "";
  }
  
  // Aktuelle Section ist die letzte in der Sequenz
  // Wir generieren Edges von allen vorherigen Sections zur aktuellen Section
  const prevSections = context.sectionSequence.slice(0, -1);
  
  const edgeCallouts: string[] = [];
  const { graphSchema, vocabulary } = context.options;
  
  for (const prevSection of prevSections) {
    // Nur wenn vorherige Section auch eine Block-ID hat
    if (!prevSection.blockId) {
      continue;
    }
    
    // WP-26: Prüfe auf Selbstreferenz (sollte nicht vorkommen, aber sicherheitshalber prüfen)
    if (prevSection.blockId === currentSection.blockId) {
      console.warn(`[WP-26] Selbstreferenz verhindert: Block-ID "${prevSection.blockId}" zeigt auf sich selbst`);
      continue;
    }
    
    // Ermittle effective_types
    const prevType = prevSection.sectionType || prevSection.noteType;
    const currentType = currentSection.sectionType || currentSection.noteType;
    
    // Lookup in graph_schema.md: prevType -> currentType
    let forwardEdgeType: string | null = null;
    if (graphSchema && prevType && currentType) {
      const hints = getHints(graphSchema, prevType, currentType);
      if (hints.typical.length > 0) {
        forwardEdgeType = hints.typical[0]; // Erster typischer Edge-Type aus graph_schema
      } else {
        // Debug: Log wenn keine typischen Edges gefunden wurden
        console.debug(`[WP-26] Keine typischen Edges gefunden für ${prevType} -> ${currentType}`);
      }
    }
    
    // Fallback: related_to
    if (!forwardEdgeType) {
      forwardEdgeType = "related_to";
    }
    
    // WP-26: Automatische Edge-Vorschläge
    // Wir generieren beide Richtungen:
    // 1. Forward-Edge: prevSection -> currentSection (mit originalem Edge-Type)
    // 2. Rückwärts-Edge: currentSection -> prevSection (mit inversem Edge-Type)
    // 
    // Beide Edges werden in der aktuellen Section eingefügt und zeigen zur prevSection
    // Der Backlink wird automatisch mitgesetzt
    
    // Rückwärts-Edge: currentSection -> prevSection (mit inversem Edge-Type)
    let inverseEdgeType: string | null = null;
    if (vocabulary) {
      inverseEdgeType = vocabulary.getInverse(forwardEdgeType);
    }
    
    // Generiere Rückwärts-Edge (currentSection -> prevSection)
    if (inverseEdgeType) {
      edgeCallouts.push(`> [!edge] ${inverseEdgeType}`);
      edgeCallouts.push(`> [[#^${prevSection.blockId}]]`);
    }
    
    // Generiere Forward-Edge als Backlink (prevSection -> currentSection)
    // Diese Edge beschreibt die Beziehung von prevSection zu currentSection
    edgeCallouts.push(`> [!edge] ${forwardEdgeType}`);
    edgeCallouts.push(`> [[#^${prevSection.blockId}]]`);
  }
  
  return edgeCallouts.join("\n");
}