import { and, eq, inArray } from "drizzle-orm";
import {
  assertCircuitDeviceRowMoveProjectCommand,
  assertCircuitDeviceRowMoveWithNewCircuitProjectCommand,
  circuitDeviceRowMoveCommandType,
  circuitDeviceRowMoveWithNewCircuitCommandType,
  createCircuitDeviceRowMoveProjectCommand,
  createCircuitDeviceRowMoveWithNewCircuitProjectCommand,
  type CircuitDeviceRowMoveAssignment,
  type CircuitDeviceRowMoveHistoryProjectCommand,
} from "../../domain/models/circuit-device-row-move-project-command.model.js";
import type { CircuitSnapshot } from "../../domain/models/circuit-structure-project-command.model.js";
import type {
  CircuitDeviceRowMoveProjectCommandStore,
  ExecuteCircuitDeviceRowMoveCommandInput,
} from "../../domain/ports/circuit-device-row-move-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 { circuitProtectionDevices } from "../schema/circuit-protection-devices.js";
import { circuitSections } from "../schema/circuit-sections.js";
import { circuits } from "../schema/circuits.js";
import { executeProjectCommandTransaction } from "./project-command-transaction.persistence.js";
import { updateDerivedCircuitVoltage } from "./project-voltage.persistence.js";
import { resolveCircuitVoltage } from "./project-voltage.persistence.js";

interface PersistedMoveRow {
  id: string;
  circuitId: string;
  sortOrder: number;
  phaseType: string | null;
}

export class CircuitDeviceRowMoveProjectCommandRepository
  implements CircuitDeviceRowMoveProjectCommandStore
{
  constructor(private readonly database: AppDatabase) {}

  execute(input: ExecuteCircuitDeviceRowMoveCommandInput) {
    this.assertSupportedCommand(input.command);

    return executeProjectCommandTransaction(
      this.database,
      input,
      (tx) =>
        this.applyCommand(tx, input.projectId, input.command)
    );
  }

  private assertSupportedCommand(
    command: CircuitDeviceRowMoveHistoryProjectCommand
  ) {
    if (command.type === circuitDeviceRowMoveCommandType) {
      assertCircuitDeviceRowMoveProjectCommand(command);
      return;
    }
    if (
      command.type ===
      circuitDeviceRowMoveWithNewCircuitCommandType
    ) {
      assertCircuitDeviceRowMoveWithNewCircuitProjectCommand(
        command
      );
      return;
    }
    throw new Error("Unsupported circuit device-row move command.");
  }

  private applyCommand(
    database: AppDatabase,
    projectId: string,
    command: CircuitDeviceRowMoveHistoryProjectCommand
  ): CircuitDeviceRowMoveHistoryProjectCommand {
    if (command.type === circuitDeviceRowMoveCommandType) {
      const rowsById = this.loadExpectedRows(
        database,
        command.payload.moves
      );
      const circuitIds = this.collectCircuitIds(
        command.payload.moves
      );
      this.assertExistingCircuitsInOneList(
        database,
        projectId,
        circuitIds
      );
      const inverse = createCircuitDeviceRowMoveProjectCommand(
        this.reverseMoves(command.payload.moves, rowsById)
      );
      this.applyMoves(database, command.payload.moves);
      this.updateReserveStates(database, circuitIds);
      this.updateVoltages(database, projectId, circuitIds);
      return inverse;
    }

    assertCircuitDeviceRowMoveWithNewCircuitProjectCommand(
      command
    );
    const { targetCircuit, targetCircuitAction, moves } =
      command.payload;
    const rowsById = this.loadExpectedRows(database, moves);
    const appliedTargetCircuit = {
      ...targetCircuit,
      voltage: resolveCircuitVoltage(
        database,
        projectId,
        targetCircuit.sectionId,
        moves.map((move) => rowsById.get(move.rowId)?.phaseType)
      ),
    };
    this.assertCircuitLocation(database, projectId, appliedTargetCircuit);

    if (targetCircuitAction === "create") {
      const sourceCircuitIds = [
        ...new Set(moves.map((move) => move.expectedCircuitId)),
      ];
      this.assertExistingCircuitsInOneList(
        database,
        projectId,
        sourceCircuitIds,
        targetCircuit.circuitListId
      );
      this.assertTargetCircuitAvailable(database, appliedTargetCircuit);
      this.insertTargetCircuit(database, appliedTargetCircuit);

      const inverse =
        createCircuitDeviceRowMoveWithNewCircuitProjectCommand(
          "delete",
          appliedTargetCircuit,
          this.reverseMoves(moves, rowsById)
        );
      this.applyMoves(database, moves);
      this.updateReserveStates(database, [
        ...sourceCircuitIds,
        targetCircuit.id,
      ]);
      this.updateVoltages(database, projectId, [
        ...sourceCircuitIds,
        targetCircuit.id,
      ]);
      return inverse;
    }

    this.assertTargetCircuitUnchanged(
      database,
      appliedTargetCircuit,
      moves.map((move) => move.rowId)
    );
    const destinationCircuitIds = [
      ...new Set(moves.map((move) => move.targetCircuitId)),
    ];
    this.assertExistingCircuitsInOneList(
      database,
      projectId,
      destinationCircuitIds,
      targetCircuit.circuitListId
    );
    const inverse =
      createCircuitDeviceRowMoveWithNewCircuitProjectCommand(
        "create",
        appliedTargetCircuit,
        this.reverseMoves(moves, rowsById)
      );
    this.applyMoves(database, moves);
    this.updateReserveStates(database, [
      targetCircuit.id,
      ...destinationCircuitIds,
    ]);
    this.updateVoltages(
      database,
      projectId,
      destinationCircuitIds
    );
    const deleted = database
      .delete(circuits)
      .where(
        and(
          eq(circuits.id, targetCircuit.id),
          eq(
            circuits.circuitListId,
            targetCircuit.circuitListId
          ),
          eq(circuits.isReserve, 1)
        )
      )
      .run();
    if (deleted.changes !== 1) {
      throw new Error(
        "Created target circuit changed before deletion."
      );
    }
    return inverse;
  }

  private updateVoltages(
    database: AppDatabase,
    projectId: string,
    circuitIds: string[]
  ) {
    for (const circuitId of new Set(circuitIds)) {
      updateDerivedCircuitVoltage(database, projectId, circuitId);
    }
  }

  private loadExpectedRows(
    database: AppDatabase,
    moves: CircuitDeviceRowMoveAssignment[]
  ) {
    const rowIds = moves.map((move) => move.rowId);
    const persistedRows = database
      .select({
        id: circuitDeviceRows.id,
        circuitId: circuitDeviceRows.circuitId,
        sortOrder: circuitDeviceRows.sortOrder,
        phaseType: circuitDeviceRows.phaseType,
      })
      .from(circuitDeviceRows)
      .where(inArray(circuitDeviceRows.id, rowIds))
      .all();
    if (persistedRows.length !== rowIds.length) {
      throw new Error(
        "One or more circuit device rows do not exist."
      );
    }

    const rowsById = new Map(
      persistedRows.map((row) => [row.id, row])
    );
    for (const move of moves) {
      const row = rowsById.get(move.rowId);
      if (
        !row ||
        row.circuitId !== move.expectedCircuitId ||
        row.sortOrder !== move.expectedSortOrder
      ) {
        throw new Error(
          "Circuit device row changed before move execution."
        );
      }
    }
    return rowsById;
  }

  private collectCircuitIds(
    moves: CircuitDeviceRowMoveAssignment[]
  ) {
    return [
      ...new Set(
        moves.flatMap((move) => [
          move.expectedCircuitId,
          move.targetCircuitId,
        ])
      ),
    ];
  }

  private assertExistingCircuitsInOneList(
    database: AppDatabase,
    projectId: string,
    circuitIds: string[],
    expectedCircuitListId?: string
  ) {
    const participatingCircuits = database
      .select({
        id: circuits.id,
        circuitListId: circuits.circuitListId,
        projectId: circuitLists.projectId,
      })
      .from(circuits)
      .innerJoin(
        circuitLists,
        eq(circuitLists.id, circuits.circuitListId)
      )
      .where(inArray(circuits.id, circuitIds))
      .all();
    if (participatingCircuits.length !== circuitIds.length) {
      throw new Error(
        "One or more move circuits do not exist."
      );
    }
    if (
      participatingCircuits.some(
        (circuit) => circuit.projectId !== projectId
      )
    ) {
      throw new Error("Move circuit does not belong to project.");
    }
    const circuitListIds = new Set(
      participatingCircuits.map(
        (circuit) => circuit.circuitListId
      )
    );
    if (
      circuitListIds.size !== 1 ||
      (expectedCircuitListId !== undefined &&
        !circuitListIds.has(expectedCircuitListId))
    ) {
      throw new Error(
        "All moved rows and targets must belong to one circuit list."
      );
    }
  }

  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.");
    }
  }

  private assertTargetCircuitAvailable(
    database: AppDatabase,
    snapshot: CircuitSnapshot
  ) {
    const existingCircuit = database
      .select({ id: circuits.id })
      .from(circuits)
      .where(eq(circuits.id, snapshot.id))
      .get();
    if (existingCircuit) {
      throw new Error("Move target 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."
      );
    }
  }

  private insertTargetCircuit(
    database: AppDatabase,
    snapshot: CircuitSnapshot
  ) {
    database
      .insert(circuits)
      .values({
        id: snapshot.id,
        circuitListId: snapshot.circuitListId,
        sectionId: snapshot.sectionId,
        equipmentIdentifier: snapshot.equipmentIdentifier,
        displayName: snapshot.displayName,
        sortOrder: snapshot.sortOrder,
        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: 1,
        remark: snapshot.remark,
      })
      .run();
    if (snapshot.protectionDevice) {
      database
        .insert(circuitProtectionDevices)
        .values(snapshot.protectionDevice)
        .run();
    }
  }

  private assertTargetCircuitUnchanged(
    database: AppDatabase,
    snapshot: CircuitSnapshot,
    expectedRowIds: string[]
  ) {
    const current = database
      .select()
      .from(circuits)
      .where(eq(circuits.id, snapshot.id))
      .get();
    if (
      !current ||
      current.circuitListId !== snapshot.circuitListId ||
      current.sectionId !== snapshot.sectionId ||
      current.equipmentIdentifier !==
        snapshot.equipmentIdentifier ||
      current.displayName !== snapshot.displayName ||
      current.sortOrder !== snapshot.sortOrder ||
      current.cableType !== snapshot.cableType ||
      current.cableCrossSection !== snapshot.cableCrossSection ||
      current.cableLength !== snapshot.cableLength ||
      current.rcdAssignment !== snapshot.rcdAssignment ||
      current.terminalDesignation !==
        snapshot.terminalDesignation ||
      current.voltage !== snapshot.voltage ||
      current.controlRequirement !==
        snapshot.controlRequirement ||
      current.status !== snapshot.status ||
      current.remark !== snapshot.remark ||
      Boolean(current.isReserve)
    ) {
      throw new Error(
        "Created target circuit changed before command execution."
      );
    }
    const protectionDevice = database
      .select()
      .from(circuitProtectionDevices)
      .where(eq(circuitProtectionDevices.circuitId, snapshot.id))
      .get();
    if (
      snapshot.protectionDevice === undefined
        ? protectionDevice !== undefined
        : snapshot.protectionDevice === null
          ? protectionDevice !== undefined
          : !protectionDevice ||
            Object.entries(snapshot.protectionDevice).some(
              ([key, value]) =>
                (protectionDevice as Record<string, unknown>)[key] !==
                value
            )
    ) {
      throw new Error(
        "Created target circuit protection changed before command execution."
      );
    }

    const currentRowIds = database
      .select({ id: circuitDeviceRows.id })
      .from(circuitDeviceRows)
      .where(eq(circuitDeviceRows.circuitId, snapshot.id))
      .all()
      .map((row) => row.id);
    const expectedRowIdSet = new Set(expectedRowIds);
    if (
      currentRowIds.length !== expectedRowIds.length ||
      currentRowIds.some((id) => !expectedRowIdSet.has(id))
    ) {
      throw new Error(
        "Created target circuit rows changed before command execution."
      );
    }
  }

  private reverseMoves(
    moves: CircuitDeviceRowMoveAssignment[],
    rowsById: Map<string, PersistedMoveRow>
  ) {
    return moves.map((move) => {
      const current = rowsById.get(move.rowId)!;
      return {
        rowId: move.rowId,
        expectedCircuitId: move.targetCircuitId,
        expectedSortOrder: move.targetSortOrder,
        targetCircuitId: current.circuitId,
        targetSortOrder: current.sortOrder,
      };
    });
  }

  private applyMoves(
    database: AppDatabase,
    moves: CircuitDeviceRowMoveAssignment[]
  ) {
    for (const move of moves) {
      const result = database
        .update(circuitDeviceRows)
        .set({
          circuitId: move.targetCircuitId,
          sortOrder: move.targetSortOrder,
        })
        .where(
          and(
            eq(circuitDeviceRows.id, move.rowId),
            eq(
              circuitDeviceRows.circuitId,
              move.expectedCircuitId
            ),
            eq(
              circuitDeviceRows.sortOrder,
              move.expectedSortOrder
            )
          )
        )
        .run();
      if (result.changes !== 1) {
        throw new Error(
          "Circuit device row changed during move execution."
        );
      }
    }
  }

  private updateReserveStates(
    database: AppDatabase,
    circuitIds: string[]
  ) {
    for (const circuitId of new Set(circuitIds)) {
      const remainingRow = database
        .select({ id: circuitDeviceRows.id })
        .from(circuitDeviceRows)
        .where(eq(circuitDeviceRows.circuitId, circuitId))
        .limit(1)
        .get();
      const updated = database
        .update(circuits)
        .set({ isReserve: remainingRow ? 0 : 1 })
        .where(eq(circuits.id, circuitId))
        .run();
      if (updated.changes !== 1) {
        throw new Error(
          "Circuit changed during device-row move execution."
        );
      }
    }
  }
}