init.go

package hermes

import (
	"errors"
	"fmt"
	"sync"

	utils "github.com/realTristan/hermes/utils"
)

// InitCache is a function that initializes a new Cache struct and returns a pointer to it.
//
// Returns:
//   - A pointer to a new Cache struct.
func InitCache() *Cache {
	return &Cache{
		data:  make(map[string]map[string]any),
		mutex: &sync.RWMutex{},
		ft:    nil,
	}
}

// Initialize the full-text for the cache
// This method is thread-safe.
// If the full-text index is already initialized, an error is returned.
//
// Parameters:
// - maxSize: the maximum number of words to store in the full-text index.
// - maxBytes: the maximum size, in bytes, of the full-text index.
//
// Returns:
// - error: If the full-text is already initialized.
func (c *Cache) FTInit(maxSize int, maxBytes int, minWordLength int) error {
	c.mutex.Lock()
	defer c.mutex.Unlock()

	// Verify that the ft has already been initialized
	if c.ft != nil {
		return errors.New("full-text already initialized")
	}

	// Initialize the FT
	return c.ftInit(maxSize, maxBytes, minWordLength)
}

// Initialize the full-text for the cache.
// This method is not thread-safe, and should only be called from an exported function.
//
// Parameters:
// - maxSize: the maximum number of words to store in the full-text index.
// - maxBytes: the maximum size, in bytes, of the full-text index.
//
// Returns:
// - error: From full-text cache insertion.
func (c *Cache) ftInit(maxSize int, maxBytes int, minWordLength int) error {
	// Initialize the FT struct
	var ft *FullText = &FullText{
		storage:       make(map[string]any),
		indices:       make(map[int]string),
		index:         0,
		maxSize:       maxSize,
		maxBytes:      maxBytes,
		minWordLength: minWordLength,
	}

	// Load the cache data
	if err := ft.insert(&c.data); err != nil {
		return err
	}

	// Update the cache full-text
	c.ft = ft

	// Return no error
	return nil
}

// Initialize the full-text index for the cache with a map.
// This method is thread-safe.
// If the full-text index is already initialized, an error is returned.
//
// Parameters:
// - data: the data to initialize the full-text index with.
// - maxSize: the maximum number of words to store in the full-text index.
// - maxBytes: the maximum size, in bytes, of the full-text index.
//
// Returns:
// - error: If the full-text is already initialized.
func (c *Cache) FTInitWithMap(data map[string]map[string]any, maxSize int, maxBytes int, minWordLength int) error {
	c.mutex.Lock()
	defer c.mutex.Unlock()

	// Verify that the cache is already initialized
	if c.ft != nil {
		return errors.New("full-text cache already initialized")
	}

	// Initialize the FT cache
	return c.ftInitWithMap(data, maxSize, maxBytes, minWordLength)
}

// Initialize the full-text for the cache with a map.
// This method is not thread-safe, and should only be called from an exported function.
//
// Parameters:
// - data: the data to initialize the full-text index with.
// - maxSize: the maximum number of words to store in the full-text index.
// - maxBytes: the maximum size, in bytes, of the full-text index.
//
// Returns:
// - error
func (c *Cache) ftInitWithMap(data map[string]map[string]any, maxSize int, maxBytes int, minWordLength int) error {
	// Initialize the FT struct
	var ft *FullText = &FullText{
		storage:       make(map[string]any),
		indices:       make(map[int]string),
		index:         0,
		maxSize:       maxSize,
		maxBytes:      maxBytes,
		minWordLength: minWordLength,
	}

	// Iterate over the cache keys and add them to the data
	for k := range c.data {
		if _, ok := data[k]; ok {
			return fmt.Errorf("key %s already exists in cache", k)
		}
		data[k] = c.data[k]
	}

	// Insert the data into the ft storage
	if err := ft.insert(&data); err != nil {
		return err
	}

	// Update the cache varoables
	c.data = data
	c.ft = ft

	// Return no error
	return nil
}

// Initialize the full-text for the cache with a JSON file.
// This method is thread-safe.
// If the full-text index is already initialized, an error is returned.
//
// Parameters:
// - file: the path to the JSON file to initialize the full-text index with.
// - maxSize: the maximum number of words to store in the full-text index.
// - maxBytes: the maximum size, in bytes, of the full-text index.
//
// Returns:
// - error: If the full-text is already initialized.
func (c *Cache) FTInitWithJson(file string, maxSize int, maxBytes int, minWordLength int) error {
	c.mutex.Lock()
	defer c.mutex.Unlock()

	// Verify that the ft cache is initialized
	if c.ft != nil {
		return errors.New("full-text cache already initialized")
	}

	// Initialize the FT
	return c.ftInitWithJson(file, maxSize, maxBytes, minWordLength)
}

// Initialize the full-text for the cache with a JSON file.
// This method is not thread-safe, and should only be called from an exported function.
//
// Parameters:
// - file: the path to the JSON file to initialize the full-text index with.
// - maxSize: the maximum number of words to store in the full-text index.
// - maxBytes: the maximum size, in bytes, of the full-text index.
//
// Returns:
// - error: Json file read error, or init with map error.
func (c *Cache) ftInitWithJson(file string, maxSize int, maxBytes int, minWordLength int) error {
	if data, err := utils.ReadJson[map[string]map[string]any](file); err != nil {
		return err
	} else {
		return c.ftInitWithMap(data, maxSize, maxBytes, minWordLength)
	}
}

// insert is a method of the FullText struct that inserts a value in the full-text cache for the specified key.
// This function is not thread-safe and should only be called from an exported function.
//
// Parameters:
//   - data: A map of maps containing the data to be inserted.
//
// Returns:
//   - An error if the full-text storage limit or byte-size limit is reached.
func (ft *FullText) insert(data *map[string]map[string]any) error {
	// Create a new temp storage
	var ts *TempStorage = NewTempStorage(ft)

	// Loop through the json data
	for cacheKey, cacheValue := range *data {
		for k, v := range cacheValue {
			if ftv := WFTGetValue(v); len(ftv) == 0 {
				continue
			} else {
				// Set the key in the provided value to the fulltext value
				(*data)[cacheKey][k] = ftv

				// Insert the value in the temp storage
				if err := ts.insert(ft, cacheKey, ftv); err != nil {
					return err
				}
			}
		}
	}

	// Iterate over the temp storage and set the values with len 1 to int
	ts.cleanSingleArrays()

	// Set the full-text cache to the temp map
	ts.updateFullText(ft)

	// Return nil for no errors
	return nil
}