import type { PromptOutput, ParticipantContext } from "./types.js";
import type { Person, Message } from "../../core/types.js";
import type { PersonIdentifier } from "../../core/types/data-items.js";
import { formatMessagesAsPlaceholders } from "../message-utils.js";

export interface PersonUpdatePromptData {
  existing_item: Person | null;
  new_person_name?: string;
  new_person_description?: string;
  new_person_relationship?: string;
  messages_context: Message[];
  messages_analyze: Message[];
  persona_name: string;
  participant_context?: ParticipantContext;
  known_identifier_types?: string[];
  suggested_identifiers?: PersonIdentifier[];
}

function participantContextSection(ctx: ParticipantContext | undefined): string {
  if (!ctx) return "";
  const lines: string[] = ["# Participant Context", "The following may help you understand who is in this conversation.", ""];
  lines.push(`## Persona: ${ctx.persona_name}`);
  if (ctx.persona_description) lines.push(ctx.persona_description);
  lines.push("");
  lines.push("## Human User");
  if (ctx.human_name) lines.push(`Name: ${ctx.human_name}`);
  if (ctx.human_age !== undefined) lines.push(`Age: ${ctx.human_age}`);
  lines.push("");
  return lines.join("\n");
}

function formatExistingPerson(person: Person): string {
  return JSON.stringify({
    identifiers: person.identifiers ?? [],
    description: person.description,
    sentiment: person.sentiment,
    relationship: person.relationship,
    exposure_current: person.exposure_current,
    exposure_desired: person.exposure_desired,
  }, null, 2);
}

export function buildPersonUpdatePrompt(data: PersonUpdatePromptData): PromptOutput {
  if (!data.persona_name) {
    throw new Error("buildPersonUpdatePrompt: persona_name is required");
  }

  const personaName = data.persona_name;
  const isNewItem = data.existing_item === null;
  const humanName = data.participant_context?.human_name;
  const isEiPersona = !isNewItem && (data.existing_item?.identifiers ?? []).some(
    i => i.type.toLowerCase() === 'ei persona'
  );

  const builtInTypes = ['Full Name', 'First Name', 'Nickname', 'Email', 'GitHub', 'Discord',
    'Roblox', 'Reddit', 'Twitter', 'FF14', 'Relationship', 'Ei Persona'];
  const userTypes = data.known_identifier_types ?? [];
  const allTypes = [...new Set([...builtInTypes, ...userTypes])].join(', ');

  const personRelationship = data.existing_item?.relationship ?? data.new_person_relationship ?? 'Unknown';
  const personName = data.existing_item?.name ?? data.new_person_name ?? 'Unknown';

  // ── WHO YOU ARE ANALYZING ──────────────────────────────────────────────────
  // This section anchors the model on the target person before anything else.
  // Local models lose context from long prompts — this must be first.

  const personFocusSection = isNewItem
    ? `# WHO YOU ARE ANALYZING

NEW PERSON — not yet in system
Relationship: ${personRelationship}
Name: ${personName === 'Unknown' ? 'Not yet known' : personName}${data.new_person_description ? `\nWhat we know: ${data.new_person_description}` : ''}

Your ONLY job is to find information about the HUMAN USER's **${personRelationship}** in the conversation and create their record. Ignore all other people mentioned — they each have their own separate records.`
    : `# WHO YOU ARE ANALYZING

EXISTING PERSON RECORD — update only if the Most Recent Messages contain new information
Name: ${personName}
Relationship: ${personRelationship}

Current record:
\`\`\`json
${formatExistingPerson(data.existing_item!)}
\`\`\`

Your ONLY job is to update THIS SPECIFIC PERSON's record based on the Most Recent Messages. Ignore all other people mentioned — they each have their own separate records.`;

  // ── TASK ──────────────────────────────────────────────────────────────────

  const taskSection = isNewItem
    ? `# Task

You are creating a new PERSON record based on what you find about the HUMAN USER's **${personRelationship}** in the conversation.

The record you create will be referenced by personas in future conversations — keep it accurate, brief, and useful.`
    : `# Task

You are scanning a conversation to update a PERSON record in the HUMAN USER's life.

Apply changes to the record above **ONLY IF DOING SO WILL PROVIDE THE HUMAN USER WITH A BETTER EXPERIENCE IN THE FUTURE**.

Detail you add should:
1. Be meaningful, accurate, or still true to the HUMAN USER in six months or more
2. **NOT** already be present in the record above`;

  // ── DESCRIPTION SECTION ───────────────────────────────────────────────────
  // Three modes:
  //   isNewItem        → brief, factual bootstrap (1-3 sentences)
  //   isEiPersona      → living identity log (accumulate, never truncate)
  //   existing regular → synthesize to current-state (3-4 sentences)

  let descriptionSection: string;

  if (isNewItem) {
    descriptionSection = `A concise summary of who this person is and how they relate to the HUMAN USER. Keep it brief and factual — only what you can confirm from the conversation.

- Capture who this person IS — their role in the user's life
- Be useful to a persona who's never heard this person's name before
- 1-3 sentences maximum
- If you know their birth date or birth year, include it as a date (e.g. "born 1986-10-28") — never as a current age (ages change, dates don't)

**ABSOLUTELY VITAL**: Do **NOT** embellish. Record only what the user actually said or demonstrated.`;

  } else if (isEiPersona) {
    descriptionSection = `This record is the HUMAN USER's **observed experience** of ${personName} over time. Think of it as field notes from someone who has been talking with this Persona across many conversations.

## Your job: add, never truncate

The description is allowed to grow. **Never remove or summarize away existing content.**

Add anything from the Most Recent Messages that:
- Records a specific thing ${personName} said, did, or demonstrated in this conversation
- Captures how the HUMAN USER experienced or related to ${personName} in this specific exchange
- Notes behavior that stands out — expected or surprising — based on what the existing log already shows

**Do NOT:**
- Synthesize the existing description down to fewer sentences
- Replace specific observations with vague summaries
- Discard detail to "keep it brief" — brevity is wrong here
- Add anything that isn't directly observed in the Most Recent Messages

If the new messages add nothing meaningful, return \`{}\`. Otherwise, return the **full updated description** — existing content preserved, new observations woven in.`;

  } else {
    descriptionSection = `A concise summary of who this person is and how they relate to the HUMAN USER. Personas use this to recognize this person and engage meaningfully when they come up.

## CRITICAL: Synthesize, don't accumulate

Every update must **rewrite** the description as a current-state summary. Never append to it.

**Good**: "Borfinda, partner of 12 years. Former marine biologist, now stay-at-home parent. Tends to ground the user when they spiral; dry sense of humor. Two kids together."

**Bad**: "Borfinda was mentioned when the user talked about moving. In a later conversation she came up again during the work stress discussion. Most recently the user said she was supportive."

The description should:
- Capture who this person IS — their role, characteristics, relationship texture
- Include what the HUMAN USER has revealed about them over time
- Read as a brief, confident summary — not a log of when they were mentioned
- Not exceed 3-4 sentences

The description should NOT:
- Append "Most recently:", "Latest mention:", or any temporal marker
- Accumulate a session-by-session history of every time this person came up
- Speculate about the person based on thin evidence
- Record someone's age — record their birth date or birth year instead (e.g. "born 1981" not "age 44")

**ABSOLUTELY VITAL**: Do **NOT** embellish — personas use their own voice. Record what the user actually said or demonstrated, not your interpretation of its emotional significance.`;
  }

  // ── IDENTIFIERS ───────────────────────────────────────────────────────────

  const identityGuard = humanName
    ? `CRITICAL: The HUMAN USER is ${humanName}. They wrote these messages. Do NOT assign their names, nicknames, or handles as identifiers for this person's record — UNLESS this IS the user's own Self record (relationship: "Self").`
    : `CRITICAL: The HUMAN USER wrote these messages. Do NOT assign their own names or handles as identifiers for this person's record — UNLESS this IS the user's own Self record (relationship: "Self"). Do NOT return \`relationship: "Self"\` unless you are certain this record is about the human user themselves.`;

  const attributionGuard = `\nONLY add an identifier if it is explicitly stated about THIS SPECIFIC PERSON — not inferred from proximity in the conversation. If two different people are discussed near each other, do NOT attribute one person's handle, email, or name to the other.`;
  const isUnknownNewPerson = isNewItem && personName === 'Unknown';
  const unknownIdentifierGuard = isUnknownNewPerson
    ? `\nThis person's name is not yet known — be especially careful: only record an identifier the conversation names for THEM specifically.`
    : '';

  const suggestedIdentifiers = data.suggested_identifiers ?? [];
  const suggestedIdentifiersBlock = !isNewItem && suggestedIdentifiers.length > 0
    ? `\n\nThe scan flagged these identifiers as POSSIBLY belonging to this person: ${suggestedIdentifiers.map(i => `\`${i.type}=${i.value}\``).join(', ')}.
For EACH, add it to \`identifiers_to_add\` ONLY if the Most Recent Messages confirm it belongs to THIS SPECIFIC PERSON. If any actually belongs to someone else mentioned in the conversation, omit it. Do not add any you cannot confirm from the conversation.`
    : '';

  const identifierSection = `${identityGuard}${attributionGuard}${unknownIdentifierGuard}

If you spot a platform handle, username, email, nickname, or full name explicitly mentioned in the conversation that isn't already in the person's identifiers, include it in \`identifiers_to_add\` (updates) or \`identifiers\` (new records). Always mark exactly one identifier as \`"is_primary": true\` — prefer the most formal or complete name.

Example of what NOT to do: if the conversation says "I talked to Priya and Marcus — Marcus's GitHub is @mcodes", do NOT add @mcodes to Priya's record; it belongs to Marcus only.

For persons with a known relationship (Father, Mother, Sibling, etc.), also look for informal terms the HUMAN USER uses to address or refer to THAT SPECIFIC PERSON (\`Dad\`, \`Pop\`, \`Mom\`, \`Sis\`, etc.) and add them as \`{ "type": "Relationship", "value": "..." }\` identifiers.

NEVER add dates, ages, birthdays, or anniversaries as identifiers. These are not identifying labels — if known, include them in the description instead.

Known identifier types: ${allTypes}. If unsure of type, use \`Nickname\`.${suggestedIdentifiersBlock}`;

  // ── OUTPUT FORMAT ─────────────────────────────────────────────────────────

  const jsonTemplate = isNewItem
    ? `{
    "identifiers": [
      { "type": "Full Name", "value": "Borfinda Lastname", "is_primary": true },
      { "type": "Nickname", "value": "Borfi" }
    ],
    "description": "...",
    "sentiment": 0.0,
    "relationship": "Mother|Friend|Coworker|AI Companion|etc.",
    "exposure_desired": 0.5,
    "exposure_impact": "high|medium|low|none",
    "quotes": [
      { "text": "exact phrase from message", "reason": "why this matters" }
    ]
  }`
    : `{
    "identifiers_to_add": [{ "type": "GitHub", "value": "handle" }],
    "description": "...",
    "sentiment": 0.0,
    "relationship": "Mother|Friend|Coworker|AI Companion|etc.",
    "exposure_desired": 0.5,
    "exposure_impact": "high|medium|low|none",
    "quotes": [
      { "text": "exact phrase from message", "reason": "why this matters" }
    ]
  }`;

  // ── SYSTEM PROMPT ASSEMBLY ─────────────────────────────────────────────────
  // Order: WHO (anchor) → task → participant context → field definitions →
  //        output format. Person details are in WHO, not repeated at the bottom.

  const system = `${personFocusSection}

${taskSection}

${participantContextSection(data.participant_context)}# Field Definitions

## Identifiers
${identifierSection}

## Description (\`description\`)
${descriptionSection}

## Sentiment (\`sentiment\`)

How the HUMAN USER feels about this PERSON overall.

Scale of -1.0 to 1.0:
- -1.0: No PERSON is more despised
- -0.5: Disliked or complicated relationship, but not without value
- 0: Neutral or unknown
- 0.5: Liked and valued
- 1.0: The most important person in their life

Do not make micro-adjustments. Close enough is OK.

## Relationship (\`relationship\`)

How the HUMAN USER is currently related to this PERSON.

Once known, this field changes infrequently — a "Father" may later be clarified to "Step-Father", but is unlikely to become "Uncle".

Keep it concise and specific. Avoid vague labels.

Examples: "Unknown" → "Coworker", "Mother" → "Step-Mother", "Fiance" → "Spouse", "AI Persona" → "AI Companion"

## Desired Exposure (\`exposure_desired\`)

How much the HUMAN USER wants to talk about this PERSON.

Scale of 0.0 to 1.0:
- 0.0: Never wants to hear about this PERSON again
- 0.5: Average amount of engagement
- 1.0: This PERSON is the sole focus of their existence

Do not make micro-adjustments. Close enough is OK.

## Exposure Impact (\`exposure_impact\`)

Not in the current data — but include it in your response.

How much this conversation should count toward exposure tracking:
- "high": Long, detailed conversation exclusively about this PERSON
- "medium": Long OR detailed conversation about this PERSON
- "low": The conversation touched on this PERSON briefly
- "none": Only alluded to or hinted at

## Quotes

Identify any **memorable, funny, important, or stand-out phrases** from the Most Recent Messages that relate to this PERSON.

**Prioritize:**
- Humor, wit, colorful language, creative profanity
- Emotional outbursts (positive or negative) — the raw stuff
- Phrases that reveal how the HUMAN USER feels about this PERSON
- Things you'd quote back to them later to make them laugh or think

**NEVER extract these:**
- Technical identifiers: ARNs, URLs, file paths, UUIDs, config keys
- AI agent self-talk or apologies
- Generic statements that could apply to anyone

**CRITICAL**: Return the EXACT text as it appears in the message.

# Output

ONLY ANALYZE the "Most Recent Messages". The "Earlier Conversation" is provided for context only — it has already been processed.

\`\`\`json
${jsonTemplate}
\`\`\`

When returning a record, **ALWAYS** include \`description\` and \`sentiment\`. Do NOT return \`relationship: "Self"\` unless this record IS the human user themselves.

If you find **NO EVIDENCE** of the HUMAN USER's **${personRelationship}** in the "Most Recent Messages", respond with: \`{}\`

If **NO CHANGES** are required, respond with: \`{}\`

An empty object is the MOST COMMON expected response.
`;

  // ── USER PROMPT ───────────────────────────────────────────────────────────

  const earlierSection =
    data.messages_context.length > 0
      ? `## Earlier Conversation
${formatMessagesAsPlaceholders(data.messages_context, personaName)}

`
      : "";

  const recentSection = `## Most Recent Messages
${formatMessagesAsPlaceholders(data.messages_analyze, personaName)}`;

  const personReminder = personName !== 'Unknown'
    ? `Remember: You are analyzing the record for **${personName}** (${personRelationship}). Focus only on information about this specific person.`
    : `Remember: You are analyzing the record for the HUMAN USER's **${personRelationship}**. Focus only on information about this specific person.`;

  const user = `# Conversation
${earlierSection}${recentSection}

---

${personReminder}

Analyze the Most Recent Messages and ${isNewItem ? 'create the PERSON record' : 'update the PERSON record'} if warranted.

**Return JSON:**
\`\`\`json
${jsonTemplate}
\`\`\`

If no ${isNewItem ? 'information found' : 'changes are needed'}, respond with: \`{}\``;

  return { system, user };
}