import { and, asc, eq, inArray } from "drizzle-orm";
import {
  assertDistributionBoardDeleteSubtreeProjectCommand,
  assertDistributionBoardInsertSubtreeProjectCommand,
  createDistributionBoardDeleteSubtreeProjectCommand,
  createDistributionBoardInsertSubtreeProjectCommand,
  distributionBoardDeleteSubtreeCommandType,
  distributionBoardInsertSubtreeCommandType,
  type DistributionBoardSubtreeProjectCommand,
} from "../../domain/models/distribution-board-subtree-project-command.model.js";
import {
  assertDistributionBoardSubtreeSnapshot,
  type DistributionBoardSubtreeSnapshot,
} from "../../domain/models/distribution-board-subtree-snapshot.model.js";
import type {
  DistributionBoardSubtreeProjectCommandStore,
  ExecuteDistributionBoardSubtreeCommandInput,
} from "../../domain/ports/distribution-board-subtree-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 { distributionBoardComponentProtectionDevices } from "../schema/distribution-board-component-protection-devices.js";
import { distributionBoardComponents } from "../schema/distribution-board-components.js";
import { distributionBoards } from "../schema/distribution-boards.js";
import { floors } from "../schema/floors.js";
import { projectDevices } from "../schema/project-devices.js";
import { projects } from "../schema/projects.js";
import { rooms } from "../schema/rooms.js";
import { executeProjectCommandTransaction } from "./project-command-transaction.persistence.js";

export class DistributionBoardSubtreeProjectCommandRepository
  implements DistributionBoardSubtreeProjectCommandStore
{
  constructor(private readonly database: AppDatabase) {}

  capture(projectId: string, distributionBoardId: string) {
    return this.captureFrom(
      this.database,
      projectId,
      distributionBoardId
    );
  }

  execute(input: ExecuteDistributionBoardSubtreeCommandInput) {
    if (input.command.type === distributionBoardInsertSubtreeCommandType) {
      assertDistributionBoardInsertSubtreeProjectCommand(input.command);
    } else {
      assertDistributionBoardDeleteSubtreeProjectCommand(input.command);
    }
    return executeProjectCommandTransaction(
      this.database,
      input,
      (tx) => this.applyCommand(tx, input.projectId, input.command)
    );
  }

  private applyCommand(
    database: AppDatabase,
    projectId: string,
    command: DistributionBoardSubtreeProjectCommand
  ) {
    if (command.type === distributionBoardInsertSubtreeCommandType) {
      this.insert(database, projectId, command.payload.snapshot);
      return createDistributionBoardDeleteSubtreeProjectCommand(
        command.payload.snapshot
      );
    }
    if (command.type === distributionBoardDeleteSubtreeCommandType) {
      const current = this.captureFrom(
        database,
        projectId,
        command.payload.snapshot.distributionBoard.id
      );
      if (!sameSnapshot(current, command.payload.snapshot)) {
        throw new Error(
          "Distribution-board subtree changed before deletion."
        );
      }
      const deleted = database
        .delete(distributionBoards)
        .where(
          and(
            eq(
              distributionBoards.id,
              current.distributionBoard.id
            ),
            eq(distributionBoards.projectId, projectId)
          )
        )
        .run();
      if (deleted.changes !== 1) {
        throw new Error(
          "Distribution-board subtree could not be deleted."
        );
      }
      return createDistributionBoardInsertSubtreeProjectCommand(
        command.payload.snapshot
      );
    }
    throw new Error("Unsupported distribution-board subtree command.");
  }

  private captureFrom(
    database: AppDatabase,
    projectId: string,
    distributionBoardId: string
  ): DistributionBoardSubtreeSnapshot {
    const distributionBoard = database
      .select()
      .from(distributionBoards)
      .where(
        and(
          eq(distributionBoards.id, distributionBoardId),
          eq(distributionBoards.projectId, projectId)
        )
      )
      .get();
    if (!distributionBoard) {
      throw new Error("Distribution board not found.");
    }
    const circuitList = database
      .select()
      .from(circuitLists)
      .where(
        and(
          eq(circuitLists.distributionBoardId, distributionBoard.id),
          eq(circuitLists.projectId, projectId)
        )
      )
      .get();
    if (!circuitList) {
      throw new Error("Distribution-board circuit list not found.");
    }
    const sections = database
      .select()
      .from(circuitSections)
      .where(eq(circuitSections.circuitListId, circuitList.id))
      .orderBy(asc(circuitSections.sortOrder), asc(circuitSections.id))
      .all();
    const components = database
      .select()
      .from(distributionBoardComponents)
      .where(eq(distributionBoardComponents.circuitListId, circuitList.id))
      .orderBy(
        asc(distributionBoardComponents.sortOrder),
        asc(distributionBoardComponents.id)
      )
      .all()
      .map((component) => ({
        component,
        protectionDevice:
          database
            .select()
            .from(distributionBoardComponentProtectionDevices)
            .where(
              eq(
                distributionBoardComponentProtectionDevices.componentId,
                component.id
              )
            )
            .get() ?? null,
      }));
    const circuitSnapshots = database
      .select()
      .from(circuits)
      .where(eq(circuits.circuitListId, circuitList.id))
      .orderBy(asc(circuits.sortOrder), asc(circuits.id))
      .all()
      .map((circuit) => {
        const { isReserve, ...values } = circuit;
        return {
          ...values,
          isReserve: Boolean(isReserve),
          deviceRows: database
            .select()
            .from(circuitDeviceRows)
            .where(eq(circuitDeviceRows.circuitId, circuit.id))
            .orderBy(
              asc(circuitDeviceRows.sortOrder),
              asc(circuitDeviceRows.id)
            )
            .all(),
          protectionDevice:
            database
              .select()
              .from(circuitProtectionDevices)
              .where(eq(circuitProtectionDevices.circuitId, circuit.id))
              .get() ?? null,
        };
      });
    const snapshot: DistributionBoardSubtreeSnapshot = {
      distributionBoard,
      circuitList,
      sections,
      components,
      circuits: circuitSnapshots,
    };
    assertDistributionBoardSubtreeSnapshot(snapshot);
    return snapshot;
  }

  private insert(
    database: AppDatabase,
    projectId: string,
    snapshot: DistributionBoardSubtreeSnapshot
  ) {
    assertDistributionBoardSubtreeSnapshot(snapshot);
    if (
      snapshot.distributionBoard.projectId !== projectId ||
      snapshot.circuitList.projectId !== projectId
    ) {
      throw new Error(
        "Distribution-board subtree belongs to another project."
      );
    }
    this.assertProjectReferences(database, projectId, snapshot);
    this.assertIdsAvailable(database, snapshot);

    database
      .insert(distributionBoards)
      .values(snapshot.distributionBoard)
      .run();
    database.insert(circuitLists).values(snapshot.circuitList).run();
    if (snapshot.sections.length > 0) {
      database.insert(circuitSections).values(snapshot.sections).run();
    }
    for (const entry of snapshot.components) {
      database
        .insert(distributionBoardComponents)
        .values(entry.component)
        .run();
      if (entry.protectionDevice !== null) {
        database
          .insert(distributionBoardComponentProtectionDevices)
          .values(entry.protectionDevice)
          .run();
      }
    }
    for (const circuit of snapshot.circuits) {
      const { deviceRows, protectionDevice, isReserve, ...values } =
        circuit;
      database
        .insert(circuits)
        .values({ ...values, isReserve: isReserve ? 1 : 0 })
        .run();
      if (protectionDevice !== null && protectionDevice !== undefined) {
        database
          .insert(circuitProtectionDevices)
          .values(protectionDevice)
          .run();
      }
      if (deviceRows.length > 0) {
        database.insert(circuitDeviceRows).values(deviceRows).run();
      }
    }
  }

  private assertProjectReferences(
    database: AppDatabase,
    projectId: string,
    snapshot: DistributionBoardSubtreeSnapshot
  ) {
    const project = database
      .select({
        enabledSupplyTypes:
          projects.enabledDistributionBoardSupplyTypes,
      })
      .from(projects)
      .where(eq(projects.id, projectId))
      .get();
    if (!project) {
      throw new Error("Project not found.");
    }
    if (
      snapshot.distributionBoard.supplyType !== null &&
      !project.enabledSupplyTypes.includes(
        snapshot.distributionBoard.supplyType
      )
    ) {
      throw new Error(
        "Distribution-board subtree uses a disabled supply type."
      );
    }
    if (snapshot.distributionBoard.floorId !== null) {
      const floor = database
        .select({ projectId: floors.projectId })
        .from(floors)
        .where(eq(floors.id, snapshot.distributionBoard.floorId))
        .get();
      if (!floor || floor.projectId !== projectId) {
        throw new Error(
          "Distribution-board floor does not belong to project."
        );
      }
    }
    const linkedProjectDeviceIds = uniqueStrings(
      snapshot.circuits.flatMap((circuit) =>
        circuit.deviceRows.flatMap((row) =>
          row.linkedProjectDeviceId === null
            ? []
            : [row.linkedProjectDeviceId]
        )
      )
    );
    if (linkedProjectDeviceIds.length > 0) {
      const references = database
        .select({ id: projectDevices.id, projectId: projectDevices.projectId })
        .from(projectDevices)
        .where(inArray(projectDevices.id, linkedProjectDeviceIds))
        .all();
      if (
        references.length !== linkedProjectDeviceIds.length ||
        references.some((reference) => reference.projectId !== projectId)
      ) {
        throw new Error(
          "Distribution-board project-device reference is invalid."
        );
      }
    }
    const roomIds = uniqueStrings(
      snapshot.circuits.flatMap((circuit) =>
        circuit.deviceRows.flatMap((row) =>
          row.roomId === null ? [] : [row.roomId]
        )
      )
    );
    if (roomIds.length > 0) {
      const references = database
        .select({ id: rooms.id, projectId: rooms.projectId })
        .from(rooms)
        .where(inArray(rooms.id, roomIds))
        .all();
      if (
        references.length !== roomIds.length ||
        references.some((reference) => reference.projectId !== projectId)
      ) {
        throw new Error("Distribution-board room reference is invalid.");
      }
    }
  }

  private assertIdsAvailable(
    database: AppDatabase,
    snapshot: DistributionBoardSubtreeSnapshot
  ) {
    const sectionIds = snapshot.sections.map((section) => section.id);
    const componentIds = snapshot.components.map(
      ({ component }) => component.id
    );
    const circuitIds = snapshot.circuits.map((circuit) => circuit.id);
    const deviceRowIds = snapshot.circuits.flatMap((circuit) =>
      circuit.deviceRows.map((row) => row.id)
    );
    const conflicts = [
      database
        .select({ id: distributionBoards.id })
        .from(distributionBoards)
        .where(eq(distributionBoards.id, snapshot.distributionBoard.id))
        .get(),
      database
        .select({ id: circuitLists.id })
        .from(circuitLists)
        .where(eq(circuitLists.id, snapshot.circuitList.id))
        .get(),
      sectionIds.length === 0
        ? undefined
        : database
            .select({ id: circuitSections.id })
            .from(circuitSections)
            .where(inArray(circuitSections.id, sectionIds))
            .limit(1)
            .get(),
      componentIds.length === 0
        ? undefined
        : database
            .select({ id: distributionBoardComponents.id })
            .from(distributionBoardComponents)
            .where(inArray(distributionBoardComponents.id, componentIds))
            .limit(1)
            .get(),
      circuitIds.length === 0
        ? undefined
        : database
            .select({ id: circuits.id })
            .from(circuits)
            .where(inArray(circuits.id, circuitIds))
            .limit(1)
            .get(),
      deviceRowIds.length === 0
        ? undefined
        : database
            .select({ id: circuitDeviceRows.id })
            .from(circuitDeviceRows)
            .where(inArray(circuitDeviceRows.id, deviceRowIds))
            .limit(1)
            .get(),
    ];
    if (conflicts.some(Boolean)) {
      throw new Error("Distribution-board subtree id already exists.");
    }
  }
}

function uniqueStrings(values: string[]) {
  return [...new Set(values)];
}

function sameSnapshot(
  left: DistributionBoardSubtreeSnapshot,
  right: DistributionBoardSubtreeSnapshot
) {
  return canonicalJson(left) === canonicalJson(right);
}

function canonicalJson(value: unknown): string {
  if (Array.isArray(value)) {
    return `[${value.map(canonicalJson).join(",")}]`;
  }
  if (value !== null && typeof value === "object") {
    return `{${Object.entries(value)
      .sort(([left], [right]) => left.localeCompare(right))
      .map(
        ([key, child]) =>
          `${JSON.stringify(key)}:${canonicalJson(child)}`
      )
      .join(",")}}`;
  }
  return JSON.stringify(value) ?? "null";
}