use serde::{Deserialize, Serialize};
use serde_json::Value;
use std::collections::BTreeMap;
use std::sync::Arc;

// Schema mirrors the Go Punc Generator's schema struct for consistency.
// It is an order-preserving representation of a JSON Schema.
#[derive(Debug, Clone, Serialize, Deserialize, Default)]
pub struct SchemaObject {
  // Core Schema Keywords
  #[serde(rename = "$id")]
  pub id: Option<String>,
  #[serde(rename = "$ref")]
  pub ref_string: Option<String>,
  #[serde(rename = "$anchor")]
  pub anchor: Option<String>,
  #[serde(rename = "$dynamicAnchor")]
  pub dynamic_anchor: Option<String>,
  #[serde(rename = "$dynamicRef")]
  pub dynamic_ref: Option<String>,
  /*
     Note: The `Ref` field in the Go struct is a pointer populated by the linker.
     In Rust, we might handle this differently (e.g., separate lookup or Rc/Arc),
     so we omit the direct recursive `Ref` field for now and rely on `ref_string`.
  */
  pub description: Option<String>,
  pub title: Option<String>,
  #[serde(default)] // Allow missing type
  #[serde(rename = "type")]
  pub type_: Option<SchemaTypeOrArray>, // Handles string or array of strings

  // Object Keywords
  pub properties: Option<BTreeMap<String, Arc<Schema>>>,
  #[serde(rename = "patternProperties")]
  pub pattern_properties: Option<BTreeMap<String, Arc<Schema>>>,
  #[serde(rename = "additionalProperties")]
  pub additional_properties: Option<Arc<Schema>>,
  pub required: Option<Vec<String>>,

  // dependencies can be schema dependencies or property dependencies
  pub dependencies: Option<BTreeMap<String, Dependency>>,

  // Definitions (for $ref resolution)
  #[serde(rename = "$defs")]
  pub defs: Option<BTreeMap<String, Arc<Schema>>>,
  #[serde(rename = "definitions")]
  pub definitions: Option<BTreeMap<String, Arc<Schema>>>,

  // Array Keywords
  #[serde(rename = "items")]
  pub items: Option<Arc<Schema>>,
  #[serde(rename = "prefixItems")]
  pub prefix_items: Option<Vec<Arc<Schema>>>,

  // String Validation
  #[serde(rename = "minLength")]
  pub min_length: Option<f64>,
  #[serde(rename = "maxLength")]
  pub max_length: Option<f64>,
  pub pattern: Option<String>,

  // Array Validation
  #[serde(rename = "minItems")]
  pub min_items: Option<f64>,
  #[serde(rename = "maxItems")]
  pub max_items: Option<f64>,
  #[serde(rename = "uniqueItems")]
  pub unique_items: Option<bool>,
  #[serde(rename = "contains")]
  pub contains: Option<Arc<Schema>>,
  #[serde(rename = "minContains")]
  pub min_contains: Option<f64>,
  #[serde(rename = "maxContains")]
  pub max_contains: Option<f64>,

  // Object Validation
  #[serde(rename = "minProperties")]
  pub min_properties: Option<f64>,
  #[serde(rename = "maxProperties")]
  pub max_properties: Option<f64>,
  #[serde(rename = "propertyNames")]
  pub property_names: Option<Arc<Schema>>,
  #[serde(rename = "dependentRequired")]
  pub dependent_required: Option<BTreeMap<String, Vec<String>>>,
  #[serde(rename = "dependentSchemas")]
  pub dependent_schemas: Option<BTreeMap<String, Arc<Schema>>>,

  // Numeric Validation
  pub format: Option<String>,
  #[serde(rename = "enum")]
  pub enum_: Option<Vec<Value>>, // `enum` is a reserved keyword in Rust
  #[serde(
    default,
    rename = "const",
    deserialize_with = "crate::util::deserialize_some"
  )]
  pub const_: Option<Value>,

  // Numeric Validation
  #[serde(rename = "multipleOf")]
  pub multiple_of: Option<f64>,
  pub minimum: Option<f64>,
  pub maximum: Option<f64>,
  #[serde(rename = "exclusiveMinimum")]
  pub exclusive_minimum: Option<f64>,
  #[serde(rename = "exclusiveMaximum")]
  pub exclusive_maximum: Option<f64>,

  // Combining Keywords
  #[serde(rename = "allOf")]
  pub all_of: Option<Vec<Arc<Schema>>>,
  #[serde(rename = "anyOf")]
  pub any_of: Option<Vec<Arc<Schema>>>,
  #[serde(rename = "oneOf")]
  pub one_of: Option<Vec<Arc<Schema>>>,
  #[serde(rename = "not")]
  pub not: Option<Arc<Schema>>,
  #[serde(rename = "if")]
  pub if_: Option<Arc<Schema>>,
  #[serde(rename = "then")]
  pub then_: Option<Arc<Schema>>,
  #[serde(rename = "else")]
  pub else_: Option<Arc<Schema>>,

  // Custom Vocabularies
  pub form: Option<Vec<String>>,
  pub display: Option<Vec<String>>,
  #[serde(rename = "enumNames")]
  pub enum_names: Option<Vec<String>>,
  pub control: Option<String>,
  pub actions: Option<BTreeMap<String, Action>>,
  pub computer: Option<String>,
  #[serde(default)]
  pub extensible: Option<bool>,

  // Compiled Fields (Hidden from JSON/Serde)
  #[serde(skip)]
  pub compiled_format: Option<crate::compiler::CompiledFormat>,
  #[serde(skip)]
  pub compiled_pattern: Option<crate::compiler::CompiledRegex>,
  #[serde(skip)]
  pub compiled_pattern_properties: Option<Vec<(crate::compiler::CompiledRegex, Arc<Schema>)>>,
  #[serde(skip)]
  pub compiled_registry: Option<Arc<crate::registry::Registry>>,
}

#[derive(Debug, Clone, Serialize)]
pub struct Schema {
  #[serde(flatten)]
  pub obj: SchemaObject,
  #[serde(skip)]
  pub always_fail: bool,
}

impl Default for Schema {
  fn default() -> Self {
    Schema {
      obj: SchemaObject::default(),
      always_fail: false,
    }
  }
}

impl std::ops::Deref for Schema {
  type Target = SchemaObject;
  fn deref(&self) -> &Self::Target {
    &self.obj
  }
}
impl std::ops::DerefMut for Schema {
  fn deref_mut(&mut self) -> &mut Self::Target {
    &mut self.obj
  }
}

impl<'de> Deserialize<'de> for Schema {
  fn deserialize<D>(deserializer: D) -> Result<Self, D::Error>
  where
    D: serde::Deserializer<'de>,
  {
    let v: Value = Deserialize::deserialize(deserializer)?;

    if let Some(b) = v.as_bool() {
      let mut obj = SchemaObject::default();
      if b {
        obj.extensible = Some(true);
      }
      return Ok(Schema {
        obj,
        always_fail: !b,
      });
    }
    let obj: SchemaObject = serde_json::from_value(v.clone()).map_err(serde::de::Error::custom)?;

    Ok(Schema {
      obj,
      always_fail: false,
    })
  }
}

#[derive(Debug, Clone, Serialize, Deserialize)]
#[serde(untagged)]
pub enum SchemaTypeOrArray {
  Single(String),
  Multiple(Vec<String>),
}

#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct Action {
  pub navigate: Option<String>,
  pub punc: Option<String>,
}
#[derive(Debug, Clone, Serialize, Deserialize)]
#[serde(untagged)]
pub enum Dependency {
  Props(Vec<String>),
  Schema(Arc<Schema>),
}