import {
  and,
  asc,
  eq,
  inArray,
  isNull,
} from "drizzle-orm";
import type { CircuitDeviceRowSnapshot } from "../../domain/models/circuit-device-row-structure-project-command.model.js";
import {
  assertProjectDeviceDeleteProjectCommand,
  assertProjectDeviceInsertProjectCommand,
  createProjectDeviceDeleteProjectCommand,
  createProjectDeviceInsertProjectCommand,
  projectDeviceDeleteCommandType,
  projectDeviceInsertCommandType,
  type ProjectDeviceSnapshot,
  type ProjectDeviceStructureProjectCommand,
} from "../../domain/models/project-device-structure-project-command.model.js";
import type {
  ExecuteProjectDeviceStructureCommandInput,
  ProjectDeviceStructureProjectCommandStore,
} from "../../domain/ports/project-device-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 { circuits } from "../schema/circuits.js";
import { projectDevices } from "../schema/project-devices.js";
import { projects } from "../schema/projects.js";
import { toCircuitDeviceRowSnapshot } from "./circuit-device-row-structure.persistence.js";
import { executeProjectCommandTransaction } from "./project-command-transaction.persistence.js";
import { resolveProjectDeviceVoltage } from "./project-voltage.persistence.js";

const circuitDeviceRowSnapshotFields = [
  "id",
  "circuitId",
  "linkedProjectDeviceId",
  "sortOrder",
  "name",
  "displayName",
  "phaseType",
  "connectionKind",
  "costGroup",
  "category",
  "level",
  "roomId",
  "roomNumberSnapshot",
  "roomNameSnapshot",
  "quantity",
  "powerPerUnit",
  "simultaneityFactor",
  "cosPhi",
  "remark",
  "overriddenFields",
] as const satisfies readonly (keyof CircuitDeviceRowSnapshot)[];

export class ProjectDeviceStructureProjectCommandRepository
  implements ProjectDeviceStructureProjectCommandStore
{
  constructor(private readonly database: AppDatabase) {}

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

  private applyCommand(
    database: AppDatabase,
    projectId: string,
    source: ExecuteProjectDeviceStructureCommandInput["source"],
    command: ProjectDeviceStructureProjectCommand
  ): ProjectDeviceStructureProjectCommand {
    if (command.type === projectDeviceInsertCommandType) {
      assertProjectDeviceInsertProjectCommand(command);
      return this.insert(
        database,
        projectId,
        source,
        command.payload.projectDevice,
        command.payload.linkedRows
      );
    }
    if (command.type === projectDeviceDeleteCommandType) {
      assertProjectDeviceDeleteProjectCommand(command);
      return this.delete(
        database,
        projectId,
        command.payload.projectDeviceId,
        command.payload.expectedProjectId
      );
    }
    throw new Error("Unsupported project-device structure command.");
  }

  private insert(
    database: AppDatabase,
    projectId: string,
    source: ExecuteProjectDeviceStructureCommandInput["source"],
    snapshot: ProjectDeviceSnapshot,
    linkedRows: CircuitDeviceRowSnapshot[]
  ) {
    if (snapshot.projectId !== projectId) {
      throw new Error(
        "Project-device snapshot does not belong to project."
      );
    }
    if (source === "user" && linkedRows.length > 0) {
      throw new Error(
        "User project-device inserts cannot reconnect existing rows."
      );
    }
    const project = database
      .select({ id: projects.id })
      .from(projects)
      .where(eq(projects.id, projectId))
      .get();
    if (!project) {
      throw new Error("Project does not exist.");
    }
    if (
      source === "user" &&
      snapshot.voltageV !==
        resolveProjectDeviceVoltage(
          database,
          projectId,
          snapshot.phaseType
        )
    ) {
      throw new Error(
        "Project-device voltage must match the project phase voltage."
      );
    }
    const existing = database
      .select({ id: projectDevices.id })
      .from(projectDevices)
      .where(eq(projectDevices.id, snapshot.id))
      .get();
    if (existing) {
      throw new Error("Project-device id already exists.");
    }

    this.assertRestorableRows(database, projectId, linkedRows);
    database.insert(projectDevices).values(snapshot).run();
    for (const row of linkedRows) {
      const updated = database
        .update(circuitDeviceRows)
        .set({ linkedProjectDeviceId: snapshot.id })
        .where(
          and(
            eq(circuitDeviceRows.id, row.id),
            isNull(circuitDeviceRows.linkedProjectDeviceId)
          )
        )
        .run();
      if (updated.changes !== 1) {
        throw new Error(
          "A restored project-device row changed during insertion."
        );
      }
    }
    return createProjectDeviceDeleteProjectCommand(
      snapshot.id,
      projectId
    );
  }

  private delete(
    database: AppDatabase,
    projectId: string,
    projectDeviceId: string,
    expectedProjectId: string
  ) {
    if (expectedProjectId !== projectId) {
      throw new Error(
        "Project-device delete project does not match command project."
      );
    }
    const projectDevice = database
      .select()
      .from(projectDevices)
      .where(
        and(
          eq(projectDevices.id, projectDeviceId),
          eq(projectDevices.projectId, projectId)
        )
      )
      .get();
    if (!projectDevice) {
      throw new Error(
        "Project device does not belong to project."
      );
    }
    const linkedRows = database
      .select({
        row: circuitDeviceRows,
        projectId: circuitLists.projectId,
      })
      .from(circuitDeviceRows)
      .innerJoin(
        circuits,
        eq(circuits.id, circuitDeviceRows.circuitId)
      )
      .innerJoin(
        circuitLists,
        eq(circuitLists.id, circuits.circuitListId)
      )
      .where(
        eq(
          circuitDeviceRows.linkedProjectDeviceId,
          projectDevice.id
        )
      )
      .orderBy(
        asc(circuitDeviceRows.sortOrder),
        asc(circuitDeviceRows.id)
      )
      .all();
    if (
      linkedRows.some((linked) => linked.projectId !== projectId)
    ) {
      throw new Error(
        "Project device has linked rows outside its project."
      );
    }
    const inverse = createProjectDeviceInsertProjectCommand(
      toProjectDeviceSnapshot(projectDevice),
      linkedRows.map(({ row }) => ({
        ...toCircuitDeviceRowSnapshot(row),
        linkedProjectDeviceId: null,
      }))
    );

    const deleted = database
      .delete(projectDevices)
      .where(
        and(
          eq(projectDevices.id, projectDevice.id),
          eq(projectDevices.projectId, projectId)
        )
      )
      .run();
    if (deleted.changes !== 1) {
      throw new Error("Project device could not be deleted.");
    }
    return inverse;
  }

  private assertRestorableRows(
    database: AppDatabase,
    projectId: string,
    snapshots: CircuitDeviceRowSnapshot[]
  ) {
    if (snapshots.length === 0) {
      return;
    }
    const rowIds = snapshots.map((row) => row.id);
    const persistedRows = database
      .select({
        row: circuitDeviceRows,
        projectId: circuitLists.projectId,
      })
      .from(circuitDeviceRows)
      .innerJoin(
        circuits,
        eq(circuits.id, circuitDeviceRows.circuitId)
      )
      .innerJoin(
        circuitLists,
        eq(circuitLists.id, circuits.circuitListId)
      )
      .where(inArray(circuitDeviceRows.id, rowIds))
      .all();
    if (
      persistedRows.length !== snapshots.length ||
      persistedRows.some(
        (persisted) => persisted.projectId !== projectId
      )
    ) {
      throw new Error(
        "One or more restored rows do not belong to project."
      );
    }
    const persistedById = new Map(
      persistedRows.map(({ row }) => [
        row.id,
        toCircuitDeviceRowSnapshot(row),
      ])
    );
    for (const snapshot of snapshots) {
      const persisted = persistedById.get(snapshot.id);
      if (
        !persisted ||
        !circuitDeviceRowSnapshotFields.every(
          (field) => persisted[field] === snapshot[field]
        )
      ) {
        throw new Error(
          "A restored project-device row changed before insertion."
        );
      }
    }
  }
}

function toProjectDeviceSnapshot(
  projectDevice: typeof projectDevices.$inferSelect
): ProjectDeviceSnapshot {
  if (
    projectDevice.phaseType !== "single_phase" &&
    projectDevice.phaseType !== "three_phase"
  ) {
    throw new Error("Persisted project-device phase type is invalid.");
  }
  return {
    id: projectDevice.id,
    projectId: projectDevice.projectId,
    name: projectDevice.name,
    displayName: projectDevice.displayName,
    phaseType: projectDevice.phaseType,
    connectionKind: projectDevice.connectionKind,
    costGroup: projectDevice.costGroup,
    category: projectDevice.category,
    quantity: projectDevice.quantity,
    powerPerUnit: projectDevice.powerPerUnit,
    simultaneityFactor: projectDevice.simultaneityFactor,
    cosPhi: projectDevice.cosPhi,
    remark: projectDevice.remark,
    voltageV: projectDevice.voltageV,
  };
}