use std::collections::HashSet;

use serde_json::Value;

use crate::validator::context::ValidationContext;
use crate::validator::error::ValidationError;
use crate::validator::result::ValidationResult;

impl<'a> ValidationContext<'a> {
  pub(crate) fn validate_object(
    &self,
    result: &mut ValidationResult,
  ) -> Result<bool, ValidationError> {
    let current = self.instance;
    if let Some(obj) = current.as_object() {
      // Entity implicit type validation
      if let Some(schema_identifier) = self.schema.identifier() {
        // We decompose identity string routing inherently
        let expected_type = schema_identifier.split('.').last().unwrap_or(&schema_identifier);
        
        // Check if the identifier represents a registered global database entity boundary mathematically
        if let Some(type_def) = self.db.types.get(expected_type) {
          if let Some(type_val) = obj.get("type") {
            if let Some(type_str) = type_val.as_str() {
              if type_def.variations.contains(type_str) {
                // The instance is validly declaring a known structural descent
                result.evaluated_keys.insert("type".to_string());
              } else {
                result.errors.push(ValidationError {
                  code: "CONST_VIOLATED".to_string(), // Aligning with original const override errors natively
                  message: format!(
                    "Type '{}' is not a valid descendant for this entity bound schema",
                    type_str
                  ),
                  path: self.join_path("type"),
                });
              }
            }
          } else {
            // Because it's a global entity target, the payload must structurally provide a discriminator natively
            result.errors.push(ValidationError {
              code: "MISSING_TYPE".to_string(),
              message: format!("Schema mechanically requires type discrimination '{}'", expected_type),
              path: self.path.clone(), // Empty boundary
            });
          }

          // If the target mathematically declares a horizontal structural STI variation natively
          if schema_identifier.contains('.') {
            if obj.get("kind").is_none() {
              result.errors.push(ValidationError {
                code: "MISSING_KIND".to_string(),
                message: "Schema mechanically requires horizontal kind discrimination".to_string(),
                path: self.path.clone(),
              });
            } else {
              result.evaluated_keys.insert("kind".to_string());
            }
          }
        } else {
          // If it isn't registered globally, it might be a nested Ad-Hoc candidate running via O(1) union routers.
          // Because they lack manual type property descriptors, we natively shield "type" and "kind" keys from
          // triggering additionalProperty violations natively IF they precisely correspond to their fast-path boundaries
          if let Some(type_val) = obj.get("type") {
             if let Some(type_str) = type_val.as_str() {
                if type_str == expected_type {
                   result.evaluated_keys.insert("type".to_string());
                }
             }
          }
          if let Some(kind_val) = obj.get("kind") {
             if let Some((kind_str, _)) = schema_identifier.rsplit_once('.') {
                if let Some(actual_kind) = kind_val.as_str() {
                   if actual_kind == kind_str {
                      result.evaluated_keys.insert("kind".to_string());
                   }
                }
             }
          }
        }
      }

      if let Some(min) = self.schema.min_properties
        && (obj.len() as f64) < min
      {
        result.errors.push(ValidationError {
          code: "MIN_PROPERTIES".to_string(),
          message: "Too few properties".to_string(),
          path: self.path.to_string(),
        });
      }

      if let Some(max) = self.schema.max_properties
        && (obj.len() as f64) > max
      {
        result.errors.push(ValidationError {
          code: "MAX_PROPERTIES".to_string(),
          message: "Too many properties".to_string(),
          path: self.path.to_string(),
        });
      }

      if let Some(ref req) = self.schema.required {
        for field in req {
          if !obj.contains_key(field) {
            if field == "type" {
              result.errors.push(ValidationError {
                code: "MISSING_TYPE".to_string(),
                message: "Missing type discriminator".to_string(),
                path: self.join_path(field),
              });
            } else {
              result.errors.push(ValidationError {
                code: "REQUIRED_FIELD_MISSING".to_string(),
                message: format!("Missing {}", field),
                path: self.join_path(field),
              });
            }
          }
        }
      }

      if let Some(ref deps) = self.schema.dependencies {
        for (prop, dep) in deps {
          if obj.contains_key(prop) {
            match dep {
              crate::database::schema::Dependency::Props(required_props) => {
                for req_prop in required_props {
                  if !obj.contains_key(req_prop) {
                    result.errors.push(ValidationError {
                      code: "DEPENDENCY_MISSING".to_string(),
                      message: format!("Property '{}' requires property '{}'", prop, req_prop),
                      path: self.path.to_string(),
                    });
                  }
                }
              }
              crate::database::schema::Dependency::Schema(dep_schema) => {
                let derived = self.derive_for_schema(dep_schema, false);
                let dep_res = derived.validate()?;
                result.evaluated_keys.extend(dep_res.evaluated_keys.clone());
                result.merge(dep_res);
              }
            }
          }
        }
      }

      if let Some(props) = &self.schema.properties {
        for (key, sub_schema) in props {
          if self.overrides.contains(key) {
            continue; // Skip validation if exactly this property was overridden by a child
          }

          if let Some(child_instance) = obj.get(key) {
            let new_path = self.join_path(key);
            let is_ref = match &sub_schema.type_ {
              Some(crate::database::schema::SchemaTypeOrArray::Single(t)) => !crate::database::schema::is_primitive_type(t),
              _ => false,
            };
            let next_extensible = if is_ref { false } else { self.extensible };

            let derived = self.derive(
              sub_schema,
              child_instance,
              &new_path,
              HashSet::new(),
              next_extensible,
              false,
            );
            let item_res = derived.validate()?;



            result.merge(item_res);
            result.evaluated_keys.insert(key.to_string());
          }
        }
      }

      if let Some(compiled_pp) = self.schema.compiled_pattern_properties.get() {
        for (compiled_re, sub_schema) in compiled_pp {
          for (key, child_instance) in obj {
            if compiled_re.0.is_match(key) {
              let new_path = self.join_path(key);
              let is_ref = match &sub_schema.type_ {
                Some(crate::database::schema::SchemaTypeOrArray::Single(t)) => !crate::database::schema::is_primitive_type(t),
                _ => false,
              };
              let next_extensible = if is_ref { false } else { self.extensible };

              let derived = self.derive(
                sub_schema,
                child_instance,
                &new_path,
                HashSet::new(),
                next_extensible,
                false,
              );
              let item_res = derived.validate()?;
              result.merge(item_res);
              result.evaluated_keys.insert(key.to_string());
            }
          }
        }
      }

      if let Some(ref additional_schema) = self.schema.additional_properties {
        for (key, child_instance) in obj {
          let mut locally_matched = false;
          if let Some(props) = &self.schema.properties
            && props.contains_key(&key.to_string())
          {
            locally_matched = true;
          }
          if !locally_matched && let Some(compiled_pp) = self.schema.compiled_pattern_properties.get()
          {
            for (compiled_re, _) in compiled_pp {
              if compiled_re.0.is_match(key) {
                locally_matched = true;
                break;
              }
            }
          }

          if !locally_matched {
            let new_path = self.join_path(key);
            let is_ref = match &additional_schema.type_ {
              Some(crate::database::schema::SchemaTypeOrArray::Single(t)) => !crate::database::schema::is_primitive_type(t),
              _ => false,
            };
            let next_extensible = if is_ref { false } else { self.extensible };

            let derived = self.derive(
              additional_schema,
              child_instance,
              &new_path,
              HashSet::new(),
              next_extensible,
              false,
            );
            let item_res = derived.validate()?;
            result.merge(item_res);
            result.evaluated_keys.insert(key.to_string());
          }
        }
      }

      if let Some(ref property_names) = self.schema.property_names {
        for key in obj.keys() {
          let _new_path = self.join_path(&format!("propertyNames/{}", key));
          let val_str = Value::String(key.to_string());

          let ctx = ValidationContext::new(
            self.db,
            self.root,
            property_names,
            &val_str,
            HashSet::new(),
            self.extensible,
            self.reporter,
          );

          result.merge(ctx.validate()?);
        }
      }
    }

    Ok(true)
  }
}