/**
 * Template-Spec v1 — Context Bridge
 *
 * Maps a structured TemplateContext (canonical entities: PROVIDER, CUSTOMER, etc.)
 * to the flat {{PLACEHOLDER}} map used by legacy templates.
 *
 * Flow:  TemplateContext → contextToPlaceholders() → Record<string, string>
 *         → string.replace({{KEY}}, value) in renderer
 */

// =============================================================================
// Types
// =============================================================================

export interface ProviderCtx {
  LEGAL_NAME: string
  LEGAL_FORM?: string
  ADDRESS_LINE: string
  POSTAL_CODE: string
  CITY: string
  COUNTRY: string
  EMAIL: string
  PHONE?: string
  WEBSITE_URL?: string
  CEO_NAME?: string
  REGISTER_COURT?: string
  REGISTER_NUMBER?: string
  VAT_ID?: string
}

export interface CustomerCtx {
  LEGAL_NAME: string
  ADDRESS_LINE?: string
  POSTAL_CODE?: string
  CITY?: string
  COUNTRY?: string
  CONTACT_NAME?: string
  EMAIL: string
  IS_CONSUMER: boolean
  IS_BUSINESS: boolean
}

export interface ServiceCtx {
  NAME: string
  DESCRIPTION: string
  MODEL: 'SaaS' | 'PaaS' | 'IaaS' | 'OnPrem' | 'Hybrid' | ''
  TIER: string
  DATA_LOCATION: string
  EXPORT_FORMATS?: string[]
  EXPORT_WINDOW_DAYS?: number
  MIN_TERM_MONTHS?: number
  TERMINATION_NOTICE_DAYS?: number
}

export interface LegalCtx {
  GOVERNING_LAW: string
  JURISDICTION_CITY: string
  VERSION_DATE: string   // YYYY-MM-DD
  EFFECTIVE_DATE: string // YYYY-MM-DD
  LANG: 'de' | 'en'
}

export interface PrivacyCtx {
  CONTACT_EMAIL: string
  DPO_NAME: string
  DPO_EMAIL: string
  SUPERVISORY_AUTHORITY_NAME?: string
  SUPERVISORY_AUTHORITY_ADDRESS?: string
  PRIVACY_POLICY_URL: string
  COOKIE_POLICY_URL?: string
  ANALYTICS_RETENTION_MONTHS?: number
  DATA_TRANSFER_THIRD_COUNTRIES?: string
}

export interface SLACtx {
  AVAILABILITY_PERCENT: number | ''
  MAINTENANCE_NOTICE_HOURS: number | ''
  SUPPORT_EMAIL: string
  SUPPORT_PHONE?: string
  SUPPORT_HOURS: string
  RESPONSE_CRITICAL_H: number | ''
  RESOLUTION_CRITICAL_H: number | ''
  RESPONSE_HIGH_H: number | ''
  RESOLUTION_HIGH_H: number | ''
  RESPONSE_MEDIUM_H: number | ''
  RESOLUTION_MEDIUM_H: number | ''
  RESPONSE_LOW_H: number | ''
}

export interface PaymentsCtx {
  MONTHLY_FEE_EUR: number | ''
  PAYMENT_DUE_DAY: number | ''
  PAYMENT_METHOD: string
  PAYMENT_DAYS: number | ''
}

export interface SecurityCtx {
  INCIDENT_NOTICE_HOURS: number | ''
  LOG_RETENTION_DAYS: number | ''
  SECURITY_LOG_RETENTION_DAYS: number | ''
}

export interface NDACtx {
  PURPOSE: string
  DURATION_YEARS: number | ''
  PENALTY_AMOUNT_EUR: number | null | ''
}

export interface ConsentCtx {
  WEBSITE_NAME: string
  ANALYTICS_TOOLS: string | null
  MARKETING_PARTNERS: string | null
}

export interface TemplateContext {
  PROVIDER: ProviderCtx
  CUSTOMER: CustomerCtx
  SERVICE: ServiceCtx
  LEGAL: LegalCtx
  PRIVACY: PrivacyCtx
  SLA: SLACtx
  PAYMENTS: PaymentsCtx
  SECURITY: SecurityCtx
  NDA: NDACtx
  CONSENT: ConsentCtx
}

export interface ComputedFlags {
  IS_B2C: boolean
  IS_B2B: boolean
  SERVICE_IS_SAAS: boolean
  SERVICE_IS_HYBRID: boolean
  HAS_PENALTY: boolean
  HAS_ANALYTICS: boolean
  HAS_MARKETING: boolean
}

// =============================================================================
// Empty default context
// =============================================================================

export const EMPTY_CONTEXT: TemplateContext = {
  PROVIDER: {
    LEGAL_NAME: '', LEGAL_FORM: '', ADDRESS_LINE: '', POSTAL_CODE: '', CITY: '',
    COUNTRY: 'DE', EMAIL: '', PHONE: '', WEBSITE_URL: '',
    CEO_NAME: '', REGISTER_COURT: '', REGISTER_NUMBER: '', VAT_ID: '',
  },
  CUSTOMER: {
    LEGAL_NAME: '', ADDRESS_LINE: '', POSTAL_CODE: '', CITY: '', COUNTRY: 'DE',
    CONTACT_NAME: '', EMAIL: '', IS_CONSUMER: false, IS_BUSINESS: true,
  },
  SERVICE: {
    NAME: '', DESCRIPTION: '', MODEL: 'SaaS', TIER: '', DATA_LOCATION: 'Deutschland',
    EXPORT_FORMATS: [], EXPORT_WINDOW_DAYS: 30, MIN_TERM_MONTHS: 12,
    TERMINATION_NOTICE_DAYS: 30,
  },
  LEGAL: {
    GOVERNING_LAW: 'Deutschland', JURISDICTION_CITY: '', VERSION_DATE: '', EFFECTIVE_DATE: '',
    LANG: 'de',
  },
  PRIVACY: {
    CONTACT_EMAIL: '', DPO_NAME: '', DPO_EMAIL: '',
    SUPERVISORY_AUTHORITY_NAME: '', SUPERVISORY_AUTHORITY_ADDRESS: '',
    PRIVACY_POLICY_URL: '', COOKIE_POLICY_URL: '',
    ANALYTICS_RETENTION_MONTHS: 13, DATA_TRANSFER_THIRD_COUNTRIES: 'nicht statt',
  },
  SLA: {
    AVAILABILITY_PERCENT: 99.5, MAINTENANCE_NOTICE_HOURS: 72,
    SUPPORT_EMAIL: '', SUPPORT_PHONE: '', SUPPORT_HOURS: 'Mo–Fr 09:00–18:00 CET',
    RESPONSE_CRITICAL_H: 2, RESOLUTION_CRITICAL_H: 8,
    RESPONSE_HIGH_H: 4, RESOLUTION_HIGH_H: 24,
    RESPONSE_MEDIUM_H: 24, RESOLUTION_MEDIUM_H: 120,
    RESPONSE_LOW_H: 72,
  },
  PAYMENTS: {
    MONTHLY_FEE_EUR: '', PAYMENT_DUE_DAY: 1, PAYMENT_METHOD: 'Rechnung', PAYMENT_DAYS: 14,
  },
  SECURITY: {
    INCIDENT_NOTICE_HOURS: 24, LOG_RETENTION_DAYS: 7, SECURITY_LOG_RETENTION_DAYS: 30,
  },
  NDA: { PURPOSE: '', DURATION_YEARS: 5, PENALTY_AMOUNT_EUR: null },
  CONSENT: { WEBSITE_NAME: '', ANALYTICS_TOOLS: null, MARKETING_PARTNERS: null },
}

// =============================================================================
// Bridge: context → flat placeholder map
// =============================================================================

function str(v: unknown): string {
  if (v === null || v === undefined || v === '') return ''
  if (Array.isArray(v)) return v.join(', ')
  return String(v)
}

/** Compute compound address from PROVIDER fields */
function providerAddress(p: ProviderCtx): string {
  const parts = [p.ADDRESS_LINE, [p.POSTAL_CODE, p.CITY].filter(Boolean).join(' ')].filter(Boolean)
  return parts.join(', ')
}

/**
 * Maps a TemplateContext to a flat Record<string, string> of placeholder values.
 * Keys are the {{PLACEHOLDER}} strings used in templates.
 */
export function contextToPlaceholders(ctx: TemplateContext): Record<string, string> {
  const p = ctx.PROVIDER
  const c = ctx.CUSTOMER
  const s = ctx.SERVICE
  const l = ctx.LEGAL
  const prv = ctx.PRIVACY
  const sla = ctx.SLA
  const pay = ctx.PAYMENTS
  const sec = ctx.SECURITY
  const nda = ctx.NDA
  const con = ctx.CONSENT

  const address = providerAddress(p)

  return {
    // --- PROVIDER ---
    '{{COMPANY_NAME}}':        str(p.LEGAL_NAME),
    '{{PROVIDER_NAME}}':       str(p.LEGAL_NAME),
    '{{DISCLOSING_PARTY}}':    str(p.LEGAL_NAME),   // NDA: provider is disclosing party
    '{{SERVICE_PROVIDER}}':    str(p.LEGAL_NAME),   // SLA
    '{{COMPANY_ADDRESS}}':     address,
    '{{PROVIDER_ADDRESS}}':    address,
    '{{CONTACT_EMAIL}}':       str(p.EMAIL),
    '{{PROVIDER_EMAIL}}':      str(p.EMAIL),
    '{{ABUSE_EMAIL}}':         str(p.EMAIL),        // AUP abuse contact
    '{{REPORT_EMAIL}}':        prv.CONTACT_EMAIL ? str(prv.CONTACT_EMAIL) : str(p.EMAIL), // community moderation

    // --- CUSTOMER ---
    '{{CUSTOMER_NAME}}':       str(c.LEGAL_NAME),
    '{{RECEIVING_PARTY}}':     str(c.LEGAL_NAME),   // NDA
    '{{CUSTOMER}}':            str(c.LEGAL_NAME),   // SLA

    // --- SERVICE ---
    '{{SERVICE_NAME}}':        str(s.NAME),
    '{{PLATFORM_NAME}}':       str(s.NAME),         // community / copyright
    '{{SERVICE_DESCRIPTION}}': str(s.DESCRIPTION),
    '{{SERVICE_MODEL}}':       str(s.MODEL),
    '{{SERVICE_TIER}}':        str(s.TIER),
    '{{DATA_LOCATION}}':       str(s.DATA_LOCATION),
    '{{EXPORT_FORMATS}}':      Array.isArray(s.EXPORT_FORMATS) ? s.EXPORT_FORMATS.join(', ') : '',
    '{{EXPORT_WINDOW_DAYS}}':  str(s.EXPORT_WINDOW_DAYS),
    '{{MIN_TERM_MONTHS}}':     str(s.MIN_TERM_MONTHS),
    '{{TERMINATION_NOTICE_DAYS}}': str(s.TERMINATION_NOTICE_DAYS),

    // --- LEGAL ---
    '{{GOVERNING_LAW}}':       str(l.GOVERNING_LAW),
    '{{JURISDICTION_CITY}}':   str(l.JURISDICTION_CITY),
    '{{VERSION_DATE}}':        str(l.VERSION_DATE),
    '{{EFFECTIVE_DATE}}':      str(l.EFFECTIVE_DATE),
    '{{START_DATE}}':          str(l.EFFECTIVE_DATE), // cloud contract start date

    // --- PRIVACY ---
    '{{PRIVACY_CONTACT_EMAIL}}': str(prv.CONTACT_EMAIL),
    '{{DPO_NAME}}':            str(prv.DPO_NAME),
    '{{DPO_EMAIL}}':           str(prv.DPO_EMAIL),
    '{{COPYRIGHT_CONTACT_NAME}}': str(prv.DPO_NAME), // copyright policy
    '{{COPYRIGHT_EMAIL}}':     str(prv.DPO_EMAIL),
    '{{PRIVACY_POLICY_URL}}':  str(prv.PRIVACY_POLICY_URL),
    '{{COOKIE_POLICY_URL}}':   str(prv.COOKIE_POLICY_URL),
    '{{ANALYTICS_RETENTION_MONTHS}}': str(prv.ANALYTICS_RETENTION_MONTHS),
    '{{DATA_TRANSFER_THIRD_COUNTRIES}}': str(prv.DATA_TRANSFER_THIRD_COUNTRIES),

    // --- SLA ---
    '{{AVAILABILITY_PERCENT}}':    str(sla.AVAILABILITY_PERCENT),
    '{{MAINTENANCE_NOTICE_HOURS}}': str(sla.MAINTENANCE_NOTICE_HOURS),
    '{{SUPPORT_EMAIL}}':           str(sla.SUPPORT_EMAIL),
    '{{SUPPORT_PHONE}}':           str(sla.SUPPORT_PHONE),
    '{{SUPPORT_HOURS}}':           str(sla.SUPPORT_HOURS),
    '{{RESPONSE_CRITICAL_H}}':     str(sla.RESPONSE_CRITICAL_H),
    '{{RESOLUTION_CRITICAL_H}}':   str(sla.RESOLUTION_CRITICAL_H),
    '{{RESPONSE_HIGH_H}}':         str(sla.RESPONSE_HIGH_H),
    '{{RESOLUTION_HIGH_H}}':       str(sla.RESOLUTION_HIGH_H),
    '{{RESPONSE_MEDIUM_H}}':       str(sla.RESPONSE_MEDIUM_H),
    '{{RESOLUTION_MEDIUM_H}}':     str(sla.RESOLUTION_MEDIUM_H),
    '{{RESPONSE_LOW_H}}':          str(sla.RESPONSE_LOW_H),

    // --- PAYMENTS ---
    '{{MONTHLY_FEE}}':         str(pay.MONTHLY_FEE_EUR),
    '{{PAYMENT_DUE_DAY}}':     str(pay.PAYMENT_DUE_DAY),
    '{{PAYMENT_METHOD}}':      str(pay.PAYMENT_METHOD),
    '{{PAYMENT_DAYS}}':        str(pay.PAYMENT_DAYS),

    // --- SECURITY ---
    '{{INCIDENT_NOTICE_HOURS}}':       str(sec.INCIDENT_NOTICE_HOURS),
    '{{LOG_RETENTION_DAYS}}':          str(sec.LOG_RETENTION_DAYS),
    '{{SECURITY_LOG_RETENTION_DAYS}}': str(sec.SECURITY_LOG_RETENTION_DAYS),

    // --- NDA ---
    '{{PURPOSE}}':             str(nda.PURPOSE),
    '{{DURATION_YEARS}}':      str(nda.DURATION_YEARS),
    '{{PENALTY_AMOUNT}}':      nda.PENALTY_AMOUNT_EUR !== null ? str(nda.PENALTY_AMOUNT_EUR) : '',

    // --- CONSENT ---
    '{{WEBSITE_NAME}}':        con.WEBSITE_NAME || str(p.WEBSITE_URL),
    '{{ANALYTICS_TOOLS}}':     str(con.ANALYTICS_TOOLS),
    '{{MARKETING_PARTNERS}}':  str(con.MARKETING_PARTNERS),
  }
}

// =============================================================================
// Computed flags
// =============================================================================

export function computeFlags(ctx: TemplateContext): ComputedFlags {
  return {
    IS_B2C:           ctx.CUSTOMER.IS_CONSUMER,
    IS_B2B:           ctx.CUSTOMER.IS_BUSINESS,
    SERVICE_IS_SAAS:  ctx.SERVICE.MODEL === 'SaaS',
    SERVICE_IS_HYBRID: ctx.SERVICE.MODEL === 'Hybrid',
    HAS_PENALTY:      ctx.NDA.PENALTY_AMOUNT_EUR !== null && ctx.NDA.PENALTY_AMOUNT_EUR !== '',
    HAS_ANALYTICS:    !!ctx.CONSENT.ANALYTICS_TOOLS,
    HAS_MARKETING:    !!ctx.CONSENT.MARKETING_PARTNERS,
  }
}

// =============================================================================
// Section relevance — which sections are useful for a given template
// =============================================================================

/** All placeholder patterns covered by each context section */
const SECTION_COVERS: Record<keyof TemplateContext, string[]> = {
  PROVIDER:  ['{{COMPANY_NAME}}', '{{PROVIDER_NAME}}', '{{DISCLOSING_PARTY}}', '{{SERVICE_PROVIDER}}', '{{COMPANY_ADDRESS}}', '{{PROVIDER_ADDRESS}}', '{{CONTACT_EMAIL}}', '{{PROVIDER_EMAIL}}', '{{ABUSE_EMAIL}}', '{{REPORT_EMAIL}}'],
  CUSTOMER:  ['{{CUSTOMER_NAME}}', '{{RECEIVING_PARTY}}', '{{CUSTOMER}}'],
  SERVICE:   ['{{SERVICE_NAME}}', '{{PLATFORM_NAME}}', '{{SERVICE_DESCRIPTION}}', '{{SERVICE_MODEL}}', '{{SERVICE_TIER}}', '{{DATA_LOCATION}}', '{{EXPORT_FORMATS}}', '{{EXPORT_WINDOW_DAYS}}', '{{MIN_TERM_MONTHS}}', '{{TERMINATION_NOTICE_DAYS}}'],
  LEGAL:     ['{{GOVERNING_LAW}}', '{{JURISDICTION_CITY}}', '{{VERSION_DATE}}', '{{EFFECTIVE_DATE}}', '{{START_DATE}}'],
  PRIVACY:   ['{{PRIVACY_CONTACT_EMAIL}}', '{{DPO_NAME}}', '{{DPO_EMAIL}}', '{{COPYRIGHT_CONTACT_NAME}}', '{{COPYRIGHT_EMAIL}}', '{{PRIVACY_POLICY_URL}}', '{{COOKIE_POLICY_URL}}', '{{ANALYTICS_RETENTION_MONTHS}}', '{{DATA_TRANSFER_THIRD_COUNTRIES}}'],
  SLA:       ['{{AVAILABILITY_PERCENT}}', '{{MAINTENANCE_NOTICE_HOURS}}', '{{SUPPORT_EMAIL}}', '{{SUPPORT_PHONE}}', '{{SUPPORT_HOURS}}', '{{RESPONSE_CRITICAL_H}}', '{{RESOLUTION_CRITICAL_H}}', '{{RESPONSE_HIGH_H}}', '{{RESOLUTION_HIGH_H}}', '{{RESPONSE_MEDIUM_H}}', '{{RESOLUTION_MEDIUM_H}}', '{{RESPONSE_LOW_H}}'],
  PAYMENTS:  ['{{MONTHLY_FEE}}', '{{PAYMENT_DUE_DAY}}', '{{PAYMENT_METHOD}}', '{{PAYMENT_DAYS}}'],
  SECURITY:  ['{{INCIDENT_NOTICE_HOURS}}', '{{LOG_RETENTION_DAYS}}', '{{SECURITY_LOG_RETENTION_DAYS}}'],
  NDA:       ['{{PURPOSE}}', '{{DURATION_YEARS}}', '{{PENALTY_AMOUNT}}'],
  CONSENT:   ['{{WEBSITE_NAME}}', '{{ANALYTICS_TOOLS}}', '{{MARKETING_PARTNERS}}'],
}

/**
 * Returns which context sections are relevant for a given list of template placeholders.
 */
export function getRelevantSections(placeholders: string[]): (keyof TemplateContext)[] {
  const pSet = new Set(placeholders)
  return (Object.keys(SECTION_COVERS) as (keyof TemplateContext)[]).filter(
    (section) => SECTION_COVERS[section].some((ph) => pSet.has(ph))
  )
}

/**
 * Returns a list of placeholder keys that are NOT covered by the context bridge.
 * These need to be filled in manually.
 */
export function getUncoveredPlaceholders(placeholders: string[], ctx: TemplateContext): string[] {
  const bridged = contextToPlaceholders(ctx)
  return placeholders.filter((ph) => !(ph in bridged))
}

/**
 * Strict validation: returns placeholder keys that are required but empty.
 * "Required" means: placeholder appears in template AND bridge covers it AND bridge produces empty string.
 */
export function getMissingRequired(placeholders: string[], ctx: TemplateContext): string[] {
  const bridged = contextToPlaceholders(ctx)
  return placeholders.filter((ph) => ph in bridged && !bridged[ph])
}

// =============================================================================
// Helpers to set nested context values by dot-path
// =============================================================================

/**
 * Returns a new TemplateContext with the value at dotPath set.
 * e.g. setContextPath(ctx, 'PROVIDER.LEGAL_NAME', 'ACME GmbH')
 */
export function setContextPath(ctx: TemplateContext, dotPath: string, value: unknown): TemplateContext {
  const [section, ...rest] = dotPath.split('.') as [keyof TemplateContext, ...string[]]
  const key = rest.join('.')
  return {
    ...ctx,
    [section]: {
      ...(ctx[section] as Record<string, unknown>),
      [key]: value,
    },
  }
}

/**
 * Get a nested context value by dot-path.
 */
export function getContextPath(ctx: TemplateContext, dotPath: string): unknown {
  const [section, ...rest] = dotPath.split('.') as [keyof TemplateContext, ...string[]]
  const sectionObj = ctx[section] as Record<string, unknown>
  return sectionObj?.[rest.join('.')]
}