import type {
  OverrideDiagnostic,
  OverrideDiagnosticCode,
  OverrideDiagnosticPhase,
  OverrideDiagnosticSeverity,
} from './contracts';

interface DiagnosticDefinition {
  readonly severity: OverrideDiagnosticSeverity;
  readonly phase: OverrideDiagnosticPhase;
  readonly message: string;
}

export const OVERRIDE_DIAGNOSTIC_REGISTRY = {
  'override.unsupported_schema_version': {
    severity: 'error',
    phase: 'parse',
    message: 'The theme override schema version is not supported.',
  },
  'override.legacy_shape': {
    severity: 'error',
    phase: 'parse',
    message: 'Legacy light/dark override buckets are not valid target 1.0.0 intent.',
  },
  'override.invalid_metadata': {
    severity: 'error',
    phase: 'parse',
    message: 'Theme override metadata is missing or malformed.',
  },
  'override.invalid_structure': {
    severity: 'error',
    phase: 'parse',
    message: 'A known theme override section is malformed.',
  },
  'override.prototype_key': {
    severity: 'error',
    phase: 'parse',
    message: 'Theme override data contains an unsafe object key or prototype.',
  },
  'override.unknown_input': {
    severity: 'warning',
    phase: 'parse',
    message: 'An unknown input was preserved but not expanded.',
  },
  'override.unknown_selection': {
    severity: 'warning',
    phase: 'parse',
    message: 'An unknown selection was preserved but not expanded.',
  },
  'override.unknown_target': {
    severity: 'warning',
    phase: 'parse',
    message: 'An unknown direct target was preserved but not expanded.',
  },
  'override.invalid_value': {
    severity: 'error',
    phase: 'parse',
    message: 'A known theme override value is invalid.',
  },
  'override.invalid_reference': {
    severity: 'error',
    phase: 'intent',
    message: 'A reference must identify an eligible primitive token.',
  },
  'override.unresolved_reference': {
    severity: 'error',
    phase: 'expand',
    message: 'A package or payload token reference could not be resolved.',
  },
  'override.literal_type_mismatch': {
    severity: 'error',
    phase: 'parse',
    message: 'A direct literal does not match the target token type.',
  },
  'override.mode_policy_violation': {
    severity: 'error',
    phase: 'intent',
    message: 'A mode-specific value is not allowed for this invariant role.',
  },
  'override.source_not_allowed': {
    severity: 'error',
    phase: 'intent',
    message: 'The selected primitive is outside the package-owned source set.',
  },
  'override.rule_violation': {
    severity: 'warning',
    phase: 'rule',
    message: 'The expanded theme violates a package-owned rule.',
  },
  'override.primitive_step_frozen': {
    severity: 'warning',
    phase: 'expand',
    message: 'A direct primitive override freezes one generated palette step.',
  },
  'override.adapter_write_failed': {
    severity: 'error',
    phase: 'adapter',
    message: 'A platform adapter failed while writing the expanded theme.',
  },
} as const satisfies Record<OverrideDiagnosticCode, DiagnosticDefinition>;

export function createOverrideDiagnostic(
  code: OverrideDiagnosticCode,
  context: Omit<OverrideDiagnostic, 'code' | 'severity' | 'phase' | 'message'> & {
    readonly severity?: OverrideDiagnosticSeverity;
    readonly phase?: OverrideDiagnosticPhase;
    readonly message?: string;
  } = {},
): OverrideDiagnostic {
  const definition = OVERRIDE_DIAGNOSTIC_REGISTRY[code];
  const { severity, phase, message, ...rest } = context;
  return {
    code,
    severity: severity ?? definition.severity,
    phase: phase ?? definition.phase,
    message: message ?? definition.message,
    ...rest,
  };
}

export function hasErrorDiagnostics(diagnostics: readonly OverrideDiagnostic[]): boolean {
  return diagnostics.some((diagnostic) => diagnostic.severity === 'error');
}