import crypto from "node:crypto";
import { and, eq, inArray } from "drizzle-orm";
import type {
  CircuitDeviceRowTransactionStore,
  CreateCircuitDeviceRowTransactionInput,
  CreateCircuitWithDeviceRowsTransactionInput,
  MoveCircuitDeviceRowsTransactionInput,
} from "../../domain/ports/circuit-device-row-transaction.store.js";
import type { AppDatabase } from "../database-context.js";
import { circuitDeviceRows } from "../schema/circuit-device-rows.js";
import { circuits } from "../schema/circuits.js";
import { toCircuitCreateValues } from "./circuit.persistence.js";
import {
  toCircuitDeviceRowCreateValues,
} from "./circuit-device-row.persistence.js";

export class CircuitDeviceRowTransactionRepository
  implements CircuitDeviceRowTransactionStore
{
  constructor(private readonly database: AppDatabase) {}

  createInCircuit(input: CreateCircuitDeviceRowTransactionInput) {
    const id = crypto.randomUUID();
    this.database.transaction((tx) => {
      const [circuit] = tx
        .select({ id: circuits.id })
        .from(circuits)
        .where(eq(circuits.id, input.circuitId))
        .limit(1)
        .all();
      if (!circuit) {
        throw new Error("Der Stromkreis ist ungültig.");
      }

      const existingRows = tx
        .select({ sortOrder: circuitDeviceRows.sortOrder })
        .from(circuitDeviceRows)
        .where(eq(circuitDeviceRows.circuitId, input.circuitId))
        .all();
      const lastSortOrder = existingRows.reduce(
        (highest, row) => Math.max(highest, row.sortOrder),
        0
      );
      const sortOrder = input.sortOrder ?? lastSortOrder + 10;

      tx
        .insert(circuitDeviceRows)
        .values(toCircuitDeviceRowCreateValues(id, { ...input, sortOrder }))
        .run();
      tx
        .update(circuits)
        .set({ isReserve: 0 })
        .where(eq(circuits.id, input.circuitId))
        .run();
    });
    return id;
  }

  createCircuitWithDeviceRows(input: CreateCircuitWithDeviceRowsTransactionInput) {
    if (input.deviceRows.length === 0) {
      throw new Error("Mindestens eine Gerätezeile ist erforderlich.");
    }

    const circuitId = crypto.randomUUID();
    const rowIds = input.deviceRows.map(() => crypto.randomUUID());
    this.database.transaction((tx) => {
      tx
        .insert(circuits)
        .values(
          toCircuitCreateValues(circuitId, {
            ...input.circuit,
            isReserve: false,
          })
        )
        .run();

      for (let index = 0; index < input.deviceRows.length; index += 1) {
        const row = input.deviceRows[index];
        tx
          .insert(circuitDeviceRows)
          .values(
            toCircuitDeviceRowCreateValues(rowIds[index], {
              ...row,
              circuitId,
              sortOrder: row.sortOrder ?? (index + 1) * 10,
            })
          )
          .run();
      }
    });

    return { circuitId, rowIds };
  }

  deleteFromCircuit(rowId: string, expectedCircuitId: string) {
    this.database.transaction((tx) => {
      const [row] = tx
        .select({ id: circuitDeviceRows.id, circuitId: circuitDeviceRows.circuitId })
        .from(circuitDeviceRows)
        .where(eq(circuitDeviceRows.id, rowId))
        .limit(1)
        .all();
      if (!row || row.circuitId !== expectedCircuitId) {
        throw new Error("Die Gerätezeile wurde vor dem Löschen verändert.");
      }

      const result = tx
        .delete(circuitDeviceRows)
        .where(
          and(
            eq(circuitDeviceRows.id, rowId),
            eq(circuitDeviceRows.circuitId, expectedCircuitId)
          )
        )
        .run();
      if (result.changes !== 1) {
        throw new Error("Die Gerätezeile konnte nicht gelöscht werden.");
      }

      const remainingRows = tx
        .select({ id: circuitDeviceRows.id })
        .from(circuitDeviceRows)
        .where(eq(circuitDeviceRows.circuitId, expectedCircuitId))
        .all();
      tx
        .update(circuits)
        .set({ isReserve: remainingRows.length === 0 ? 1 : 0 })
        .where(eq(circuits.id, expectedCircuitId))
        .run();
    });
  }

  moveRows(input: MoveCircuitDeviceRowsTransactionInput) {
    if (input.rows.length === 0) {
      throw new Error("Keine Gerätezeilen zum Verschieben angegeben.");
    }
    if (Boolean(input.targetCircuitId) === Boolean(input.createTargetCircuit)) {
      throw new Error("Für die Mehrfachverschiebung muss genau ein Ziel angegeben werden.");
    }

    const rowIds = input.rows.map((row) => row.id);
    if (new Set(rowIds).size !== rowIds.length) {
      throw new Error("Gerätezeilen dürfen nicht mehrfach ausgewählt sein.");
    }

    const createdCircuitId = input.createTargetCircuit ? crypto.randomUUID() : undefined;
    const targetCircuitId = input.targetCircuitId ?? createdCircuitId!;

    this.database.transaction((tx) => {
      const persistedRows = tx
        .select({ id: circuitDeviceRows.id, circuitId: circuitDeviceRows.circuitId })
        .from(circuitDeviceRows)
        .where(inArray(circuitDeviceRows.id, rowIds))
        .all();
      if (persistedRows.length !== input.rows.length) {
        throw new Error("Eine oder mehrere Gerätezeilen sind ungültig.");
      }

      const persistedRowsById = new Map(persistedRows.map((row) => [row.id, row]));
      for (const expectedRow of input.rows) {
        if (
          persistedRowsById.get(expectedRow.id)?.circuitId !==
          expectedRow.expectedCircuitId
        ) {
          throw new Error(
            "Eine Gerätezeile wurde vor Abschluss der Verschiebung verändert."
          );
        }
      }

      let targetCircuit: { id: string; circuitListId: string };
      if (input.createTargetCircuit) {
        tx
          .insert(circuits)
          .values({
            id: targetCircuitId,
            circuitListId: input.createTargetCircuit.circuitListId,
            sectionId: input.createTargetCircuit.sectionId,
            equipmentIdentifier: input.createTargetCircuit.equipmentIdentifier,
            displayName: input.createTargetCircuit.displayName,
            sortOrder: input.createTargetCircuit.sortOrder,
            isReserve: 0,
          })
          .run();
        targetCircuit = {
          id: targetCircuitId,
          circuitListId: input.createTargetCircuit.circuitListId,
        };
      } else {
        const [persistedTargetCircuit] = tx
          .select({ id: circuits.id, circuitListId: circuits.circuitListId })
          .from(circuits)
          .where(eq(circuits.id, targetCircuitId))
          .limit(1)
          .all();
        if (!persistedTargetCircuit) {
          throw new Error("Der Zielstromkreis ist ungültig.");
        }
        targetCircuit = persistedTargetCircuit;
      }

      const sourceCircuitIds = [
        ...new Set(input.rows.map((row) => row.expectedCircuitId)),
      ];
      const sourceCircuits = tx
        .select({ id: circuits.id, circuitListId: circuits.circuitListId })
        .from(circuits)
        .where(inArray(circuits.id, sourceCircuitIds))
        .all();
      if (sourceCircuits.length !== sourceCircuitIds.length) {
        throw new Error("Einer oder mehrere Quellstromkreise sind ungültig.");
      }
      if (
        sourceCircuits.some(
          (circuit) => circuit.circuitListId !== targetCircuit.circuitListId
        )
      ) {
        throw new Error(
          "Alle verschobenen Zeilen müssen zur Stromkreisliste des Ziels gehören."
        );
      }

      const movedRowIdSet = new Set(rowIds);
      const retainedTargetRows = tx
        .select({ id: circuitDeviceRows.id, sortOrder: circuitDeviceRows.sortOrder })
        .from(circuitDeviceRows)
        .where(eq(circuitDeviceRows.circuitId, targetCircuitId))
        .all()
        .filter((row) => !movedRowIdSet.has(row.id));
      const lastTargetSortOrder = retainedTargetRows.reduce(
        (highest, row) => Math.max(highest, row.sortOrder),
        0
      );

      for (let index = 0; index < input.rows.length; index += 1) {
        const row = input.rows[index];
        const result = tx
          .update(circuitDeviceRows)
          .set({
            circuitId: targetCircuitId,
            sortOrder: lastTargetSortOrder + (index + 1) * 10,
          })
          .where(
            and(
              eq(circuitDeviceRows.id, row.id),
              eq(circuitDeviceRows.circuitId, row.expectedCircuitId)
            )
          )
          .run();
        if (result.changes !== 1) {
          throw new Error(
            "Eine Gerätezeile wurde vor Abschluss der Verschiebung verändert."
          );
        }
      }

      for (const sourceCircuitId of sourceCircuitIds) {
        const remainingRows = tx
          .select({ id: circuitDeviceRows.id })
          .from(circuitDeviceRows)
          .where(eq(circuitDeviceRows.circuitId, sourceCircuitId))
          .all();
        tx
          .update(circuits)
          .set({ isReserve: remainingRows.length === 0 ? 1 : 0 })
          .where(eq(circuits.id, sourceCircuitId))
          .run();
      }
      tx
        .update(circuits)
        .set({ isReserve: 0 })
        .where(eq(circuits.id, targetCircuitId))
        .run();
    });

    return {
      movedRowIds: rowIds,
      targetCircuitId,
      createdCircuitId,
    };
  }
}