import { and, asc, eq, inArray } from "drizzle-orm";
import {
  assertCircuitDeleteProjectCommand,
  assertCircuitInsertProjectCommand,
  circuitDeleteCommandType,
  circuitInsertCommandType,
  createCircuitDeleteProjectCommand,
  createCircuitInsertProjectCommand,
  type CircuitSnapshot,
  type CircuitStructureProjectCommand,
} from "../../domain/models/circuit-structure-project-command.model.js";
import type {
  CircuitStructureProjectCommandStore,
  ExecuteCircuitStructureCommandInput,
} from "../../domain/ports/circuit-structure-project-command.store.js";
import type { AppDatabase } from "../database-context.js";
import { circuitDeviceRows } from "../schema/circuit-device-rows.js";
import { circuitLists } from "../schema/circuit-lists.js";
import { circuitSections } from "../schema/circuit-sections.js";
import { circuits } from "../schema/circuits.js";
import {
  assertCircuitDeviceRowReferencesInProject,
  toCircuitDeviceRowSnapshot,
} from "./circuit-device-row-structure.persistence.js";
import { executeProjectCommandTransaction } from "./project-command-transaction.persistence.js";

export class CircuitStructureProjectCommandRepository
  implements CircuitStructureProjectCommandStore
{
  constructor(private readonly database: AppDatabase) {}

  execute(input: ExecuteCircuitStructureCommandInput) {
    return executeProjectCommandTransaction(
      this.database,
      input,
      (tx) =>
        this.applyCommand(
          tx,
          input.projectId,
          input.source,
          input.command
        )
    );
  }

  private applyCommand(
    database: AppDatabase,
    projectId: string,
    source: ExecuteCircuitStructureCommandInput["source"],
    command: CircuitStructureProjectCommand
  ): CircuitStructureProjectCommand {
    if (command.type === circuitInsertCommandType) {
      assertCircuitInsertProjectCommand(command);
      return this.insert(
        database,
        projectId,
        source,
        command.payload.circuit
      );
    }
    if (command.type === circuitDeleteCommandType) {
      assertCircuitDeleteProjectCommand(command);
      return this.delete(
        database,
        projectId,
        command.payload.circuitId,
        command.payload.expectedCircuitListId
      );
    }
    throw new Error("Unsupported circuit structure command.");
  }

  private insert(
    database: AppDatabase,
    projectId: string,
    source: ExecuteCircuitStructureCommandInput["source"],
    snapshot: CircuitSnapshot
  ) {
    this.assertCircuitLocation(database, projectId, snapshot);

    const existingCircuit = database
      .select({ id: circuits.id })
      .from(circuits)
      .where(eq(circuits.id, snapshot.id))
      .get();
    if (existingCircuit) {
      throw new Error("Circuit id already exists.");
    }
    const duplicateIdentifier = database
      .select({ id: circuits.id })
      .from(circuits)
      .where(
        and(
          eq(circuits.circuitListId, snapshot.circuitListId),
          eq(
            circuits.equipmentIdentifier,
            snapshot.equipmentIdentifier
          )
        )
      )
      .get();
    if (duplicateIdentifier) {
      throw new Error(
        "Duplicate equipmentIdentifier in circuit list."
      );
    }

    if (snapshot.deviceRows.length > 0) {
      const rowIds = snapshot.deviceRows.map((row) => row.id);
      const existingRow = database
        .select({ id: circuitDeviceRows.id })
        .from(circuitDeviceRows)
        .where(inArray(circuitDeviceRows.id, rowIds))
        .limit(1)
        .get();
      if (existingRow) {
        throw new Error("Circuit device-row id already exists.");
      }
      for (const row of snapshot.deviceRows) {
        if (source === "user" && row.legacyConsumerId !== null) {
          throw new Error(
            "User commands cannot assign legacy consumer ids."
          );
        }
        assertCircuitDeviceRowReferencesInProject(
          database,
          projectId,
          row
        );
      }
    }

    database
      .insert(circuits)
      .values({
        id: snapshot.id,
        circuitListId: snapshot.circuitListId,
        sectionId: snapshot.sectionId,
        equipmentIdentifier: snapshot.equipmentIdentifier,
        displayName: snapshot.displayName,
        sortOrder: snapshot.sortOrder,
        protectionType: snapshot.protectionType,
        protectionRatedCurrent: snapshot.protectionRatedCurrent,
        protectionCharacteristic: snapshot.protectionCharacteristic,
        cableType: snapshot.cableType,
        cableCrossSection: snapshot.cableCrossSection,
        cableLength: snapshot.cableLength,
        rcdAssignment: snapshot.rcdAssignment,
        terminalDesignation: snapshot.terminalDesignation,
        voltage: snapshot.voltage,
        controlRequirement: snapshot.controlRequirement,
        status: snapshot.status,
        isReserve: snapshot.isReserve ? 1 : 0,
        remark: snapshot.remark,
      })
      .run();
    if (snapshot.deviceRows.length > 0) {
      database.insert(circuitDeviceRows).values(snapshot.deviceRows).run();
    }

    return createCircuitDeleteProjectCommand(
      snapshot.id,
      snapshot.circuitListId
    );
  }

  private delete(
    database: AppDatabase,
    projectId: string,
    circuitId: string,
    expectedCircuitListId: string
  ) {
    const circuit = database
      .select()
      .from(circuits)
      .where(eq(circuits.id, circuitId))
      .get();
    if (!circuit || circuit.circuitListId !== expectedCircuitListId) {
      throw new Error("Circuit changed before command execution.");
    }
    const owningList = database
      .select({ id: circuitLists.id })
      .from(circuitLists)
      .where(
        and(
          eq(circuitLists.id, circuit.circuitListId),
          eq(circuitLists.projectId, projectId)
        )
      )
      .get();
    if (!owningList) {
      throw new Error("Circuit does not belong to project.");
    }

    const rows = database
      .select()
      .from(circuitDeviceRows)
      .where(eq(circuitDeviceRows.circuitId, circuit.id))
      .orderBy(
        asc(circuitDeviceRows.sortOrder),
        asc(circuitDeviceRows.id)
      )
      .all();
    const inverse = createCircuitInsertProjectCommand({
      id: circuit.id,
      circuitListId: circuit.circuitListId,
      sectionId: circuit.sectionId,
      equipmentIdentifier: circuit.equipmentIdentifier,
      displayName: circuit.displayName,
      sortOrder: circuit.sortOrder,
      protectionType: circuit.protectionType,
      protectionRatedCurrent: circuit.protectionRatedCurrent,
      protectionCharacteristic: circuit.protectionCharacteristic,
      cableType: circuit.cableType,
      cableCrossSection: circuit.cableCrossSection,
      cableLength: circuit.cableLength,
      rcdAssignment: circuit.rcdAssignment,
      terminalDesignation: circuit.terminalDesignation,
      voltage: circuit.voltage,
      controlRequirement: circuit.controlRequirement,
      status: circuit.status,
      isReserve: Boolean(circuit.isReserve),
      remark: circuit.remark,
      deviceRows: rows.map(toCircuitDeviceRowSnapshot),
    });

    const result = database
      .delete(circuits)
      .where(
        and(
          eq(circuits.id, circuitId),
          eq(circuits.circuitListId, expectedCircuitListId)
        )
      )
      .run();
    if (result.changes !== 1) {
      throw new Error("Circuit could not be deleted.");
    }
    return inverse;
  }

  private assertCircuitLocation(
    database: AppDatabase,
    projectId: string,
    snapshot: CircuitSnapshot
  ) {
    const list = database
      .select({ id: circuitLists.id })
      .from(circuitLists)
      .where(
        and(
          eq(circuitLists.id, snapshot.circuitListId),
          eq(circuitLists.projectId, projectId)
        )
      )
      .get();
    if (!list) {
      throw new Error("Circuit list does not belong to project.");
    }
    const section = database
      .select({ id: circuitSections.id })
      .from(circuitSections)
      .where(
        and(
          eq(circuitSections.id, snapshot.sectionId),
          eq(
            circuitSections.circuitListId,
            snapshot.circuitListId
          )
        )
      )
      .get();
    if (!section) {
      throw new Error("Section does not belong to circuit list.");
    }
  }
}