/// OPENSEARCH TUTORIAL: Comprehensive Query Examples for Bakery Management System
/// This tutorial covers: Basic CRUD, Search, Aggregations, Multi-search, and Percolator queries
/// Use Elasticsearch VSCode extension for easy execution

/// Get Elasticsearch version information
GET /


/// ===================================================
/// STEP 1: INDEX SETUP AND DATA PREPARATION
/// ===================================================

/// Delete the index if it exists (cleanup for fresh start)
DELETE /bakery-items

/// Create the index with proper field mappings
/// - keyword: exact match fields (item names, categories)
/// - float: numeric values (prices)
/// - date: timestamp fields
/// - boolean: true/false flags
/// - nested: complex objects with sub-properties
PUT /bakery-items
{
  "mappings": {
    "properties": {
      "item": {
        "type": "keyword"           // Exact match for item names
      },
      "category": {
        "type": "keyword"           // Exact match for categories (cakes, bread)
      },
      "price": {
        "type": "float"             // Numeric field for price calculations
      },
      "baked_date": {
        "type": "date"              // Date field for temporal queries
      },
      "product_type": {
        "type": "keyword"           // Sale or rent classification
      },
      "is_bulk_discount": {
        "type": "boolean"           // Boolean flag for discount eligibility
      },
      "ingrediants": {
        "type": "nested",           // Nested type for complex ingredient objects
        "properties": {
          "name": {
            "type": "keyword"       // Exact match for ingredient names
          }
        }
      }
    }
  }
}

/// Sample Data Ingestion - Creating diverse test data
/// ===================================================

/// Insert chocolate cake (regular price, no discount)
POST /bakery-items/_doc
{ "item": "Chocolate Cake", 
  "category": "cakes", 
  "price": 15, 
  "baked_date": "2023-07-01T00:00:00Z",
  "product_type": "sale",
  "is_bulk_discount": false,
  "ingrediants": [ { "name": "chocolate" }, { "name": "flour" } ]
}

/// Insert chocolate cake (higher price, with bulk discount)
POST /bakery-items/_doc
{ 
  "item": "Chocolate Cake", 
  "category": "cakes", 
  "price": 18, 
  "baked_date": "2023-07-04T00:00:00Z",
  "product_type": "sale",
  "is_bulk_discount": true,
  "ingrediants": [ { "name": "chocolate" }, { "name": "flour" } ]
} 

/// Insert vanilla cake (rental item, lower price)
POST /bakery-items/_doc
{ 
  "item": "Vanilla Cake", 
  "category": "cakes", 
  "price": 12, 
  "baked_date": "2023-07-02T00:00:00Z",
  "product_type": "rent",
  "is_bulk_discount": false,
  "ingrediants": [ { "name": "vanilla" }, { "name": "flour" } ]
}

/// Insert croissant (sale item with unusual ingredients)
POST /bakery-items/_doc
{ 
  "item": "Croissant", 
  "category": "cakes", 
  "price": 5, 
  "baked_date": "2023-07-03T00:00:00Z" ,
  "product_type": "sale",
  "is_bulk_discount": true,
  "ingrediants": [ { "name": "sauce" }, { "name": "vinegar" } ]
}

/// Insert sourdough bread (bread category, no discount)
POST /bakery-items/_doc
{
  "item": "Sourdough Bread",
  "category": "bread",
  "price": 8,
  "baked_date": "2023-07-05T00:00:00Z",
  "product_type": "sale",
  "is_bulk_discount": false,
  "ingrediants": [ { "name": "flour" }, { "name": "yeast" } ]
}

/// Insert whole wheat bread (bread category, with bulk discount)
POST /bakery-items/_doc
{
  "item": "Whole Wheat Bread",
  "category": "bread",
  "price": 6,
  "baked_date": "2023-07-07T00:00:00Z",
  "product_type": "sale",
  "is_bulk_discount": true,
  "ingrediants": [ { "name": "whole wheat flour" }, { "name": "water" } ]
}

/// Insert baguette (rental bread item)
POST /bakery-items/_doc
{
  "item": "Baguette",
  "category": "bread",
  "price": 3,
  "baked_date": "2023-07-06T00:00:00Z",
  "product_type": "rent",
  "is_bulk_discount": false,
  "ingrediants": [ { "name": "flour" }, { "name": "water" } ]
}
/// ===================================================

/// ===================================================
/// STEP 2: BASIC SEARCH QUERIES
/// ===================================================

/// Basic search: Find all items in "cakes" category, sorted by price
/// Uses match query for text matching and sort for ordering results
GET /bakery-items/_search
{
  "query": {
    "match": {
      "category": "cakes"
    }
  },
  "sort": ["price"]
}

/// ===================================================
/// STEP 3: ADVANCED SEARCH WITH COLLAPSE
/// ===================================================

/// Collapse results by category: Show one representative item per category
/// Useful for creating category overview pages
GET /bakery-items/_search
{
  "query": {
    "match_all": {}               // Match all documents in the index
  },
  "collapse": {
    "field": "category",          // Group results by category field
    "inner_hits": {
      "name": "category_hits",    // Name for the grouped results
      "size": 2                   // Show top 2 items per category
    }
  },
  "sort": ["price"]               // Primary sort by price (determines which item represents each category)
}

/// FAILED EXAMPLE: Collapse by nested field (doesn't work as expected)
/// Demonstrates common mistake - collapse doesn't work directly with nested fields
GET /bakery-items/_search
{
  "query": {
    "match": {
      "category": "cakes"
    }
  },
  "inner_hits": {
    "ingrediants": {
      "name": "ingredient_hits",
      "collapse": {
        "field": "ingrediants.name"  // This approach doesn't work for nested fields
      }
    }
  },
  "sort": ["price"]
}


/// ===================================================
/// STEP 4: AGGREGATIONS - NESTED FIELD ANALYSIS
/// ===================================================

/// Get unique ingredients in cakes category using nested aggregation
/// Demonstrates how to work with nested objects in aggregations
GET /bakery-items/_search
{
  "size": 0,
  "query": {
    "match": {
      "category": "cakes"
    }
  },
  "aggs": {
    "unique_ingredients": {
      "nested": {
        "path": "ingrediants"
      },
      "aggs": {
        "ingredient_names": {
          "terms": {
            "field": "ingrediants.name",
            "size": 10
          }
        }
      }
    }
  }
}

/// ===================================================
/// STEP 5: CATEGORY-BASED AGGREGATIONS WITH TOP HITS
/// ===================================================

/// Group all items by category and show actual documents for each category
/// Useful for creating detailed category pages with sample items
GET /bakery-items/_search
{
  "size": 0,                      // Don't return top-level hits
  "aggs": {
    "by_category": {
      "terms": {
        "field": "category",      // Create buckets for each category
        "size": 10                // Support up to 10 categories
      },
      "aggs": {
        "category_docs": {
          "top_hits": {
            "size": 100           // Return up to 100 documents per category
          }
        }
      }
    }
  }
}

/// ===================================================
/// STEP 6: COMPLEX NESTED AGGREGATION WITH REVERSE NESTED
/// ===================================================

/// Advanced: Aggregate by ingredient names and show parent documents
/// Demonstrates nested → reverse_nested pattern for complex analysis
GET /bakery-items/_search
{
  "query": {
    // "match_all": {}  // Match all documents
    "match": {
      "category": "cakes"
    }
  },
  "size": 0,  // No Top Level hits needed
  "aggs": {
    "ingredients_stats": {
      "nested": {
        "path": "ingrediants"
      },
      "aggs": {
        "ingredient_names": {
          "terms": {
            "field": "ingrediants.name",
            "size": 10
          },
          "aggs": {
            "back_to_parent": {
              "reverse_nested": {},
              "aggs": {
                "parent_docs": {
                  "top_hits": {
                    "size": 100
                  }
                }
              }
            }
          }
        }
      }
    }
  }
}

/// ===================================================
/// STEP 7: MULTI-LEVEL AGGREGATIONS WITH FILTERS
/// ===================================================

/// Complex aggregation: Group by product_type, then apply multiple filters
/// Demonstrates filters aggregation for creating detailed business reports
GET /bakery-items/_search
{
  "size": 0,                      // Only aggregation results needed
  "aggs": {
    "product_type_buckets": {
      "terms": {
        "field": "product_type",  // First level: group by sale/rent
        "size": 10
      },
      "aggs": {
        "sale_or_discount": {
          "filters": {            // Second level: apply multiple filter criteria
            "filters": {
              "is_bulk_discount": {
                "term": {
                  "is_bulk_discount": true    // Filter 1: Items with bulk discount
                }
              },
              "sale": {
                "bool": {
                  "must": [
                    { "term": { "product_type": "sale" } },      // Filter 2: Sale items
                    { "term": { "is_bulk_discount": false } }    // without bulk discount
                  ]
                }
              },
              "rent": {
                "term": {
                  "product_type": "rent"      // Filter 3: Rental items
                }
              }
            }
          },
          "aggs": {
            "top_items": {
              "top_hits": {
                "size": 5         // Show top 5 items in each filter bucket
              }
            }
          }
        }
      }
    }
  }
}

/// ===================================================
/// STEP 8: MULTI-SEARCH API (BATCH QUERIES)
/// ===================================================

/// Execute multiple searches in a single request for better performance
/// Each pair of lines represents: 1) search parameters, 2) query body
/// (Note: This won't work in Elasticsearch VSCode extension, but you can't get it working in curl)
GET /_msearch
{ "index": "bakery-items"}
{ "query": { "term": { "is_bulk_discount": true } }, "size": 5, "_source": ["item", "category", "price", "product_type", "is_bulk_discount"] }
{ "index": "bakery-items"}
{ "query": { "bool": { "must": [ { "term": { "product_type": "sale" } }, { "term": { "is_bulk_discount": false } } ] } }, "size": 5, "_source": ["item", "category", "price", "product_type", "is_bulk_discount"] }
{ "index": "bakery-items"}
{ "query": { "term": { "product_type": "rent" } }, "size": 5, "_source": ["item", "category", "price", "product_type", "is_bulk_discount"] }



/// ===================================================
/// STEP 9: PERCOLATOR QUERIES (REVERSE SEARCH)
/// ===================================================

/// Reverse search setup: Instead of "find documents matching a query"
/// Percolator enables "find queries matching a document"
/// Use case: Customer alerts, recommendation engines, real-time matching

/// Delete any existing percolator index
DELETE /bakery-alerts

/// Create percolator index with special "percolator" field type
/// Must include mappings for all fields that will be used in stored queries
PUT /bakery-alerts
{
  "mappings": {
    "properties": {
      "query": {
        "type": "percolator"      // Special field type for storing queries
      },
      "category": {
        "type": "keyword"         // Must match source index mapping
      },
      "price": {
        "type": "float"           // Must match source index mapping
      },
      "is_bulk_discount": {
        "type": "boolean"         // Must match source index mapping
      }
    }
  }
}

/// Store Customer 1's preference as a percolator query
/// "Alert me when cakes under $15 are available"
PUT /bakery-alerts/_doc/cake_under_15
{
  "query": {
    "bool": {
      "must": [
        { "term": { "category": "cakes" } },
        { "range": { "price": { "lt": 15 } } }
      ]
    }
  }
}

/// Store Customer 2's preference as a percolator query  
/// "Alert me when bread items have bulk discounts"
PUT /bakery-alerts/_doc/bread_bulk_discount
{
  "query": {
    "bool": {
      "must": [
        { "term": { "category": "bread" } },
        { "term": { "is_bulk_discount": true } }
      ]
    }
  }
}

/// Test the percolator: Check which customer alerts match a new product
/// This query asks: "Which stored customer preferences match this vanilla cake?"
GET /bakery-alerts/_search
{
  "query": {
    "percolate": {
      "field": "query",           // Use the percolator field
      "document": {               // Test document against stored queries
        "item": "Vanilla Cake",
        "category": "cakes",
        "price": 12,              // Price: $12 (matches cake_under_15 alert)
        "baked_date": "2023-07-02T00:00:00Z",
        "product_type": "rent",
        "is_bulk_discount": false,
        "ingrediants": [ { "name": "vanilla" }, { "name": "flour" } ]
      }
    }
  }
}