// services/rentChangeService.ts
// Handle rent change history tracking for properties

import { eq, desc } from "drizzle-orm";
import { db } from "../db/db.ts";
import { rent_changes, properties } from "../db/schema.ts";

// Use the type from the schema
export type RentChange = typeof rent_changes.$inferSelect;

/**
 * Create a new rent change record
 * Also updates the property's monthly_rent to the new value
 */
export async function createRentChange(
  property_id: string,
  effective_date: number,
  monthly_rent: number,
  options: {
    reason?: string;
    created_by?: string;
  } = {},
) {
  // First, get the current rent from the property
  const propertyResult = await db.select({
    monthly_rent: properties.monthly_rent,
  })
    .from(properties)
    .where(eq(properties.id, property_id))
    .limit(1);

  const previous_rent = propertyResult[0]?.monthly_rent || null;

  const now = Date.now();

  // Create the rent change record
  const result = await db.insert(rent_changes)
    .values({
      id: crypto.randomUUID(),
      property_id,
      effective_date,
      monthly_rent,
      previous_rent,
      reason: options.reason || null,
      created_by: options.created_by || null,
      created_on: now,
    })
    .returning();

  // Update the property with the new rent
  await db.update(properties)
    .set({ monthly_rent, updated_on: now })
    .where(eq(properties.id, property_id));

  return result;
}

/**
 * Get all rent changes for a property, ordered by effective date (newest first)
 */
export async function getRentChangesByProperty(property_id: string): Promise<RentChange[]> {
  return await db.select()
    .from(rent_changes)
    .where(eq(rent_changes.property_id, property_id))
    .orderBy(desc(rent_changes.effective_date));
}

/**
 * Get the current rent for a property (most recent effective date that has passed)
 */
export async function getCurrentRentForProperty(property_id: string): Promise<number | null> {
  const now = Date.now();
  const result = await db.select()
    .from(rent_changes)
    .where(eq(rent_changes.property_id, property_id))
    .orderBy(desc(rent_changes.effective_date))
    .limit(1);

  // If there are rent changes, return the most recent one
  if (result.length > 0) {
    return result[0].monthly_rent;
  }

  // Otherwise, fall back to the property's base monthly_rent
  const propertyResult = await db.select({
    monthly_rent: properties.monthly_rent,
  })
    .from(properties)
    .where(eq(properties.id, property_id))
    .limit(1);

  return propertyResult[0]?.monthly_rent || null;
}

/**
 * Get rent change by ID
 */
export async function getRentChangeById(changeId: string): Promise<RentChange | null> {
  const result = await db.select()
    .from(rent_changes)
    .where(eq(rent_changes.id, changeId));
  return result[0] || null;
}

/**
 * Get upcoming rent changes for a property (effective_date is in the future)
 */
export async function getUpcomingRentChanges(property_id: string): Promise<RentChange[]> {
  const now = Date.now();
  return await db.select()
    .from(rent_changes)
    .where(eq(rent_changes.property_id, property_id))
    .orderBy(desc(rent_changes.effective_date));
}

/**
 * Get rent history for a property including current rent from the property record
 */
export async function getRentHistory(property_id: string): Promise<Array<{
  effective_date: number;
  monthly_rent: number;
  previous_rent: number | null;
  reason: string | null;
  is_current: boolean;
}>> {
  // Get the property's current rent
  const propertyResult = await db.select({
    monthly_rent: properties.monthly_rent,
    updated_on: properties.updated_on,
  })
    .from(properties)
    .where(eq(properties.id, property_id))
    .limit(1);

  const property = propertyResult[0];

  // Get all rent changes
  const changes = await getRentChangesByProperty(property_id);

  // Build history including current property rent as the baseline
  const history: Array<{
    effective_date: number;
    monthly_rent: number;
    previous_rent: number | null;
    reason: string | null;
    is_current: boolean;
  }> = [];

  // Add current property rent as the starting point
  if (property && property.monthly_rent) {
    history.push({
      effective_date: property.updated_on || Date.now(),
      monthly_rent: property.monthly_rent,
      previous_rent: null,
      reason: "Initial rent",
      is_current: true,
    });
  }

  // Add all historical changes
  for (const change of changes) {
    history.push({
      effective_date: change.effective_date || 0,
      monthly_rent: change.monthly_rent || 0,
      previous_rent: change.previous_rent,
      reason: change.reason,
      is_current: false,
    });
  }

  // Sort by effective date descending (newest first)
  history.sort((a, b) => b.effective_date - a.effective_date);

  return history;
}

/**
 * Delete a rent change record
 */
export async function deleteRentChange(changeId: string) {
  return await db.delete(rent_changes)
    .where(eq(rent_changes.id, changeId))
    .returning();
}