using System.Collections.Immutable;

namespace StellaOps.PolicyDsl;

public abstract record SyntaxNode(SourceSpan Span);

public sealed record PolicyDocumentNode(
    string Name,
    string Syntax,
    ImmutableDictionary<string, PolicyLiteralValue> Metadata,
    ImmutableArray<PolicyProfileNode> Profiles,
    ImmutableDictionary<string, PolicyLiteralValue> Settings,
    ImmutableArray<PolicyRuleNode> Rules,
    SourceSpan Span) : SyntaxNode(Span);

public sealed record PolicyProfileNode(
    string Name,
    ImmutableArray<PolicyProfileItemNode> Items,
    SourceSpan Span) : SyntaxNode(Span);

public abstract record PolicyProfileItemNode(SourceSpan Span);

public sealed record PolicyProfileMapNode(
    string Name,
    ImmutableArray<PolicyProfileMapEntryNode> Entries,
    SourceSpan Span) : PolicyProfileItemNode(Span);

public sealed record PolicyProfileMapEntryNode(
    string Source,
    decimal Weight,
    SourceSpan Span) : SyntaxNode(Span);

public sealed record PolicyProfileEnvNode(
    string Name,
    ImmutableArray<PolicyProfileEnvEntryNode> Entries,
    SourceSpan Span) : PolicyProfileItemNode(Span);

public sealed record PolicyProfileEnvEntryNode(
    PolicyExpression Condition,
    decimal Weight,
    SourceSpan Span) : SyntaxNode(Span);

public sealed record PolicyProfileScalarNode(
    string Name,
    PolicyLiteralValue Value,
    SourceSpan Span) : PolicyProfileItemNode(Span);

public sealed record PolicyRuleNode(
    string Name,
    int Priority,
    PolicyExpression When,
    ImmutableArray<PolicyActionNode> ThenActions,
    ImmutableArray<PolicyActionNode> ElseActions,
    string? Because,
    SourceSpan Span) : SyntaxNode(Span);

public abstract record PolicyActionNode(SourceSpan Span);

public sealed record PolicyAssignmentActionNode(
    PolicyReference Target,
    PolicyExpression Value,
    SourceSpan Span) : PolicyActionNode(Span);

public sealed record PolicyAnnotateActionNode(
    PolicyReference Target,
    PolicyExpression Value,
    SourceSpan Span) : PolicyActionNode(Span);

public sealed record PolicyIgnoreActionNode(
    PolicyExpression? Until,
    string? Because,
    SourceSpan Span) : PolicyActionNode(Span);

public sealed record PolicyEscalateActionNode(
    PolicyExpression? To,
    PolicyExpression? When,
    SourceSpan Span) : PolicyActionNode(Span);

public sealed record PolicyRequireVexActionNode(
    ImmutableDictionary<string, PolicyExpression> Conditions,
    SourceSpan Span) : PolicyActionNode(Span);

public sealed record PolicyWarnActionNode(
    PolicyExpression? Message,
    SourceSpan Span) : PolicyActionNode(Span);

public sealed record PolicyDeferActionNode(
    PolicyExpression? Until,
    SourceSpan Span) : PolicyActionNode(Span);

public abstract record PolicyExpression(SourceSpan Span);

public sealed record PolicyLiteralExpression(object? Value, SourceSpan Span) : PolicyExpression(Span);

public sealed record PolicyListExpression(ImmutableArray<PolicyExpression> Items, SourceSpan Span) : PolicyExpression(Span);

public sealed record PolicyIdentifierExpression(string Name, SourceSpan Span) : PolicyExpression(Span);

public sealed record PolicyMemberAccessExpression(PolicyExpression Target, string Member, SourceSpan Span) : PolicyExpression(Span);

public sealed record PolicyInvocationExpression(PolicyExpression Target, ImmutableArray<PolicyExpression> Arguments, SourceSpan Span) : PolicyExpression(Span);

public sealed record PolicyIndexerExpression(PolicyExpression Target, PolicyExpression Index, SourceSpan Span) : PolicyExpression(Span);

public sealed record PolicyUnaryExpression(PolicyUnaryOperator Operator, PolicyExpression Operand, SourceSpan Span) : PolicyExpression(Span);

public sealed record PolicyBinaryExpression(PolicyExpression Left, PolicyBinaryOperator Operator, PolicyExpression Right, SourceSpan Span) : PolicyExpression(Span);

public enum PolicyUnaryOperator
{
    Not,
}

public enum PolicyBinaryOperator
{
    And,
    Or,
    Equal,
    NotEqual,
    LessThan,
    LessThanOrEqual,
    GreaterThan,
    GreaterThanOrEqual,
    In,
    NotIn,
}

public sealed record PolicyReference(ImmutableArray<string> Segments, SourceSpan Span)
{
    public override string ToString() => string.Join(".", Segments);
}

public abstract record PolicyLiteralValue(SourceSpan Span);

public sealed record PolicyStringLiteral(string Value, SourceSpan Span) : PolicyLiteralValue(Span);

public sealed record PolicyNumberLiteral(decimal Value, SourceSpan Span) : PolicyLiteralValue(Span);

public sealed record PolicyBooleanLiteral(bool Value, SourceSpan Span) : PolicyLiteralValue(Span);

public sealed record PolicyListLiteral(ImmutableArray<PolicyLiteralValue> Items, SourceSpan Span) : PolicyLiteralValue(Span);