import { HttpErrorResponse, httpResource } from '@angular/common/http';
import { NgTemplateOutlet } from '@angular/common';
import { ChangeDetectionStrategy, Component, computed, inject, linkedSignal, signal } from '@angular/core';
import { toSignal } from '@angular/core/rxjs-interop';
import { ActivatedRoute, Router, RouterLink } from '@angular/router';
import type { SlListResponse } from '@basic-erp/sap-types';
import { map } from 'rxjs';
import { API_URL, apiErrorMessage } from '../../core/api';
import { formatNumber } from '../../core/format';
import { SlDocumentApi } from '../../core/sl/sl-document';
import { DateField, LookupField, NumberField, SboField, TextField, TextInput, TextareaField } from '../../shared/form';
import type { GridLine, GridMultiAdd } from '../../shared/grid/grid.types';
import { LinesGrid } from '../../shared/grid/lines-grid';
import type { VhLookup } from '../../shared/value-help/value-help.types';
import { Icon, MenuButton, type MenuItem, SboWindow, Toolbar, type StatusMessage, type WindowBadge } from '../../shared/window';
import { ValueHelp } from '../../shared/value-help/value-help';
import type { ListRow } from '../../shared/list/list.types';
import {
  type DocRecord,
  type NavTarget,
  computeTotals,
  createPayload,
  isBlankLine,
  isDocumentReadOnly,
  taxRateMap,
  updatePayload,
  validateLayout,
} from './document-model';
import { type ComputedSource, WAREHOUSE_LOOKUP, hasFolio, headerKeysOf, requiredHeaderOf } from './document-layouts';
import { type CopyOrigin, copyFromDocument, copySources, copyTargets } from './document-copy';
import { DOCUMENT_SCREENS, type DocumentScreen, docNum, documentStatus, menuLabel } from './document-screens';
import { ITEMS_MULTI_ADD } from './line-columns';

const today = (): string => new Date().toISOString().slice(0, 10);
const DATE_KEYS = new Set(['DocDate', 'DocDueDate', 'RequriedDate']);
/** SAP devuelve las fechas como `2026-01-05T00:00:00Z`; el campo de fecha y el guardado usan `2026-01-05`. */
const dateOnly = (v: unknown): string => (typeof v === 'string' ? v.slice(0, 10) : '');
const pickHeader = (doc: DocRecord | undefined, keys: readonly string[], blank: DocRecord): DocRecord => {
  if (!doc) return blank;
  return Object.fromEntries(
    keys.map((k) => [
      k,
      DATE_KEYS.has(k) ? dateOnly(doc[k]) : k === 'FolioNumber' ? text(doc[k]) : (doc[k] ?? (k === 'DiscountPercent' ? 0 : '')),
    ]),
  );
};
const text = (v: unknown): string => (v === null || v === undefined ? '' : String(v));
/** El folio se edita como texto; SAP lo espera como número. */
const folioAsNumber = (h: DocRecord): DocRecord => {
  const folio = h['FolioNumber'];
  if (typeof folio !== 'string') return h;
  return { ...h, FolioNumber: folio.trim() === '' ? null : Number(folio) };
};

/**
 * Formulario de un documento de ventas o compras: `nuevo` (vacío) o `:docEntry` (ver / editar).
 * Los cerrados y cancelados quedan en solo lectura. Al modificar se envía el `odata.etag` leído
 * (`If-Match`): si otro usuario cambió el documento, SAP responde 412 y se avisa sin pisarlo.
 */
@Component({
  selector: 'sbo-document-form-page',
  changeDetection: ChangeDetectionStrategy.OnPush,
  imports: [DateField, Icon, LinesGrid, LookupField, MenuButton, NgTemplateOutlet, NumberField, RouterLink, SboField, SboWindow, TextField, TextInput, TextareaField, Toolbar, ValueHelp],
  templateUrl: './document-form.page.html',
  styles: `
    h1 { margin: 0 0 6px; font-size: 18px; font-weight: 600; }
    p { margin: 0; color: var(--quiet); }
    a { color: var(--focus); }
    .totals { display: grid; gap: 2px; }
  `,
})
export class DocumentFormPage {
  private readonly route = inject(ActivatedRoute);
  private readonly router = inject(Router);
  private readonly api = inject(SlDocumentApi);

  protected readonly title = this.route.snapshot.data['title'] as string;
  protected readonly screen = this.route.snapshot.data['screen'] as DocumentScreen;
  protected readonly partner = this.screen.partner;
  /** Qué campos y columnas lleva este documento (lo declara su pantalla); el formulario solo lo dibuja. */
  protected readonly layout = this.screen.layout;
  private readonly lineSpec = this.layout.lines;
  private readonly headerKeys: readonly string[] = headerKeysOf(this.layout);
  private readonly hasFolio = hasFolio(this.layout);
  private readonly blankHeader: DocRecord = this.layout.newHeader();
  private pick(doc: DocRecord | undefined): DocRecord {
    return pickHeader(doc, this.headerKeys, this.blankHeader);
  }
  private docLines(doc: DocRecord | undefined): GridLine[] {
    return (doc?.[this.lineSpec.key] as GridLine[] | undefined) ?? [];
  }
  protected readonly docEntry = toSignal(
    this.route.paramMap.pipe(map((p) => (p.has('docEntry') ? Number(p.get('docEntry')) : null))),
    { initialValue: this.route.snapshot.paramMap.has('docEntry') ? Number(this.route.snapshot.paramMap.get('docEntry')) : null },
  );
  protected readonly isNew = computed(() => this.docEntry() === null);

  // --- datos ---------------------------------------------------------------------------------

  private readonly docResource = httpResource<DocRecord>(() => {
    const id = this.docEntry();
    return id === null ? undefined : `${API_URL}/sl/${this.screen.resource}/${id}`;
  });
  private readonly taxResource = httpResource<SlListResponse<DocRecord>>(() =>
    this.partner
      ? { url: `${API_URL}/sl/${this.partner.taxResource}`, params: { $select: 'Code,Rate', $top: 500 } }
      : undefined,
  );

  protected readonly doc = computed(() => (this.docResource.hasValue() ? this.docResource.value() : undefined));
  protected readonly loading = computed(() => this.docResource.isLoading());
  protected readonly loadError = computed(() => {
    const err = this.docResource.error();
    return err ? (err instanceof HttpErrorResponse && err.status === 404 ? 'El documento no existe.' : apiErrorMessage(err)) : '';
  });

  /** Valores editables; se reinician al cargar o recargar el documento. */
  protected readonly header = linkedSignal<DocRecord>(() => this.pick(this.doc()));
  protected readonly lines = linkedSignal<readonly GridLine[]>(() => this.docLines(this.doc()).map((l) => ({ ...l })));
  protected readonly partnerName = linkedSignal(() => text(this.doc()?.['CardName']));
  /** RUT del socio: lo completa SAP desde el maestro; aquí solo se muestra. */
  protected readonly partnerTaxId = linkedSignal(() => text(this.doc()?.['FederalTaxID']));

  // --- estado --------------------------------------------------------------------------------

  protected readonly readOnly = computed(() => isDocumentReadOnly(this.doc()) || (!!this.layout.immutable && !this.isNew()));
  protected readonly saving = signal(false);
  private readonly message = signal<StatusMessage | null>(
    ((): StatusMessage | null => {
      const created = (this.router.currentNavigation()?.extras.state as { created?: string } | undefined)?.created;
      return created ? { kind: 'ok', text: `Documento ${created} creado.` } : null;
    })(),
  );
  protected readonly conflict = signal(false);

  protected readonly status = computed<StatusMessage>(() => {
    if (this.loading()) return { kind: 'info', text: 'Cargando…' };
    if (this.loadError()) return { kind: 'err', text: this.loadError() };
    const message = this.message();
    if (message) return message;
    if (this.readOnly()) {
      const posted = this.layout.immutable && !isDocumentReadOnly(this.doc());
      return { kind: 'info', text: posted ? 'Documento contabilizado: solo lectura.' : 'Documento cerrado o cancelado: solo lectura.' };
    }
    if (this.isNew()) {
      return { kind: 'info', text: this.partner ? `Indique el ${this.partner.label.toLowerCase()} y las líneas.` : 'Complete la cabecera y las líneas.' };
    }
    return { kind: 'info', text: this.dirty() ? 'Hay cambios sin guardar.' : '' };
  });
  protected readonly badge = computed<WindowBadge | undefined>(() => {
    if (this.isNew()) return { label: 'Nueva', tone: 'info' };
    const d = this.doc();
    return d ? documentStatus(d) : undefined;
  });
  protected readonly windowTitle = computed(() => {
    const num = this.doc()?.['DocNum'];
    return num === undefined ? this.title : `${this.title} · ${text(num)}`;
  });

  protected readonly dirty = computed(() => {
    const d = this.doc();
    if (!d) return text(this.header()['CardCode']) !== '' || this.lines().some((l) => !isBlankLine(l));
    const { body } = updatePayload(this.pick(d), this.header(), this.docLines(d), this.lines(), this.lineSpec);
    return Object.keys(body).length > 0;
  });

  // --- totales -------------------------------------------------------------------------------

  private readonly rates = computed(() =>
    taxRateMap(this.taxResource.hasValue() ? this.taxResource.value().value : []),
  );
  protected readonly totals = computed(() =>
    computeTotals(this.lines(), this.rates(), Number(this.header()['DiscountPercent'] ?? 0)),
  );
  protected readonly fmt = (n: number): string => formatNumber(n, 2);

  // --- copiar de / a ----------------------------------------------------------------------------

  private readonly copyOrigin = (this.router.currentNavigation()?.extras.state as { copyFrom?: CopyOrigin } | undefined)?.copyFrom;
  protected readonly copyListFor = signal<string | null>(null);

  /** "Copiar a": solo desde un documento guardado, abierto y sin cambios pendientes. */
  protected readonly copyToItems = computed<MenuItem[]>(() => {
    const blocked = this.isNew() || this.readOnly() || this.dirty();
    return copyTargets(this.screen.path).map((p) => ({ id: p, label: menuLabel(p), disabled: blocked }));
  });
  protected readonly copyFromItems = computed<MenuItem[]>(() =>
    copySources(this.screen.path).map((p) => ({ id: p, label: menuLabel(p), disabled: !this.isNew() })),
  );
  protected readonly copyListTitle = computed(() => menuLabel(this.copyListFor() ?? ''));
  protected readonly copyListScreen = computed(() => DOCUMENT_SCREENS.find((s) => s.path === this.copyListFor()));
  /** Documentos abiertos del origen elegido, del mismo socio si ya se indicó. */
  protected readonly copyListFilter = computed(() => {
    const card = text(this.header()['CardCode']);
    return [`DocumentStatus eq 'bost_Open'`, `Cancelled eq 'tNO'`, ...(card ? [`CardCode eq '${card.replace(/'/g, "''")}'`] : [])].join(' and ');
  });
  protected readonly copyListColumns = [
    docNum,
    { key: 'CardCode', title: this.partner?.label ?? 'Socio', width: '120px', mono: true },
    { key: 'CardName', title: 'Nombre' },
    { key: 'DocDate', title: 'Fecha', type: 'date', align: 'center', width: '105px' },
  ] as const;

  protected copyTo(path: string): void {
    const docEntry = this.docEntry();
    if (docEntry === null) return;
    const origin: CopyOrigin = { path: this.screen.path, docEntry };
    void this.router.navigateByUrl(`${path}/nuevo`, { state: { copyFrom: origin } });
  }

  protected copyFrom(path: string): void {
    this.copyListFor.set(path);
  }

  protected async copyPicked(rows: ListRow[]): Promise<void> {
    const path = this.copyListFor();
    this.copyListFor.set(null);
    const docEntry = rows[0]?.['DocEntry'];
    if (path && typeof docEntry === 'number') await this.loadCopy({ path, docEntry });
  }

  /** Trae el documento origen y vuelca sus datos y líneas abiertas en el formulario. */
  private async loadCopy(origin: CopyOrigin): Promise<void> {
    const source = DOCUMENT_SCREENS.find((s) => s.path === origin.path);
    if (!source) return;
    try {
      const doc = await this.api.get(source.resource, origin.docEntry);
      const copied = copyFromDocument(doc, origin.path, menuLabel(origin.path));
      const card = text(this.header()['CardCode']);
      if (card && card !== text(copied.header['CardCode'])) {
        this.message.set({ kind: 'warn', text: `El documento es de ${text(copied.header['CardCode'])}; este es de ${card}.` });
        return;
      }
      if (!copied.lines.length) {
        this.message.set({ kind: 'warn', text: 'El documento no tiene líneas abiertas para copiar.' });
        return;
      }
      if (!card) {
        this.header.update((h) => ({ ...h, ...copied.header }));
        this.partnerName.set(text(doc['CardName']));
        this.partnerTaxId.set(text(doc['FederalTaxID']));
      }
      this.lines.update((ls) => [...ls.filter((l) => !isBlankLine(l)), ...copied.lines]);
      this.message.set({
        kind: 'ok',
        text: `Copiado de ${menuLabel(origin.path).toLowerCase()} ${text(doc['DocNum'])}${copied.skipped ? ` (${copied.skipped} línea(s) cerradas no se copian)` : ''}. Revise y pulse Crear.`,
      });
    } catch (e) {
      this.message.set({ kind: 'err', text: apiErrorMessage(e) });
    }
  }

  // --- configuración de la vista --------------------------------------------------------------

  protected readonly columns = this.layout.columns;
  protected readonly newLine = () => this.layout.newLine(this.header());
  protected readonly recalc = this.layout.recalc;
  protected readonly multi: GridMultiAdd = {
    ...ITEMS_MULTI_ADD,
    toLine: (item) => this.layout.columns[0].lookup!.apply(item, this.layout.newLine(this.header())),
  };
  protected readonly warehouseLookup = WAREHOUSE_LOOKUP;
  protected readonly partnerLookup: VhLookup = {
    title: this.partner?.type === 'cSupplier' ? 'Proveedores' : 'Clientes',
    resource: 'BusinessPartners',
    baseFilter: `CardType eq '${this.partner?.type ?? 'cCustomer'}'`,
    orderby: 'CardCode',
    columns: [
      { key: 'CardCode', title: 'Código', width: '130px', mono: true },
      { key: 'CardName', title: 'Nombre' },
    ],
    extraFields: ['FederalTaxID'],
  };

  protected str = text;

  /** Valor de una fila de solo lectura (número del documento, datos del socio, totales). */
  protected computedValue(source: ComputedSource): string {
    switch (source) {
      case 'docNum':
        return text(this.doc()?.['DocNum']);
      case 'partnerName':
        return this.partnerName();
      case 'partnerTaxId':
        return this.partnerTaxId();
      case 'subtotal':
        return this.fmt(this.totals().subtotal);
      case 'tax':
        return this.fmt(this.totals().tax);
      case 'total':
        return this.fmt(this.totals().total);
    }
  }

  constructor() {
    if (this.copyOrigin) void this.loadCopy(this.copyOrigin);
  }

  protected setHeader(key: string, value: unknown): void {
    this.header.update((h) => ({ ...h, [key]: value }));
    this.message.set(null);
  }

  /** Al escribir otro código el nombre anterior ya no vale; se completa al salir del campo o al elegir de la lista. */
  protected onPartnerText(code: string): void {
    if (code === text(this.header()['CardCode'])) return;
    this.setHeader('CardCode', code);
    this.partnerName.set('');
    this.partnerTaxId.set('');
  }

  protected notify(textMessage: string): void {
    this.message.set({ kind: 'warn', text: textMessage });
  }

  protected onPartner(row: Record<string, unknown>): void {
    this.partnerName.set(text(row['CardName']));
    this.partnerTaxId.set(text(row['FederalTaxID']));
  }

  protected setLines(lines: readonly GridLine[]): void {
    this.lines.set(lines);
    this.message.set(null);
  }

  // --- acciones ------------------------------------------------------------------------------

  protected async go(target: NavTarget): Promise<void> {
    try {
      const entry = await this.api.neighbour(this.screen.resource, target, this.docEntry());
      if (entry === null) {
        this.message.set({ kind: 'warn', text: 'No hay más documentos en esa dirección.' });
        return;
      }
      this.message.set(null);
      await this.router.navigate(['..', entry], { relativeTo: this.route });
    } catch (e) {
      this.message.set({ kind: 'err', text: apiErrorMessage(e) });
    }
  }

  protected async save(): Promise<void> {
    if (this.saving() || this.readOnly()) return;
    const errors = validateLayout(this.header(), this.lines(), requiredHeaderOf(this.layout), this.layout.requiredLine);
    if (this.hasFolio && !/^\d*$/.test(text(this.header()['FolioNumber']).trim())) errors.push('El número de folio debe ser numérico.');
    if (errors.length) {
      this.message.set({ kind: 'err', text: errors[0] });
      return;
    }
    this.saving.set(true);
    this.conflict.set(false);
    try {
      const d = this.doc();
      if (!d) {
        const header = folioAsNumber(this.layout.beforeCreate?.(this.header()) ?? this.header());
        const created = await this.api.create(this.screen.resource, createPayload(header, this.lines(), this.lineSpec));
        await this.router.navigate(['..', created['DocEntry']], {
          relativeTo: this.route,
          state: { created: text(created['DocNum']) },
        });
        return;
      }
      const update = updatePayload(this.pick(d), this.header(), this.docLines(d), this.lines(), this.lineSpec);
      const body = folioAsNumber(update.body);
      const replaceLines = update.replaceLines;
      if (!Object.keys(body).length) {
        this.message.set({ kind: 'info', text: 'No hay cambios que guardar.' });
        return;
      }
      await this.api.update(this.screen.resource, this.docEntry()!, body, text(d['odata.etag']) || undefined, replaceLines);
      this.message.set({ kind: 'ok', text: 'Documento actualizado.' });
      this.docResource.reload();
    } catch (e) {
      if (e instanceof HttpErrorResponse && e.status === 412) {
        this.conflict.set(true);
        this.message.set({
          kind: 'warn',
          text: 'Otro usuario modificó este documento. Recárguelo para ver sus cambios; los suyos no se guardaron.',
        });
      } else {
        this.message.set({ kind: 'err', text: apiErrorMessage(e) });
      }
    } finally {
      this.saving.set(false);
    }
  }

  protected reload(): void {
    this.conflict.set(false);
    this.message.set(null);
    this.docResource.reload();
  }
}