package database

import (
	"context"
	"database/sql"
	"fmt"
	"time"
)

type SnapshotRepository struct {
	db *DB
}

func NewSnapshotRepository(db *DB) *SnapshotRepository {
	return &SnapshotRepository{db: db}
}

func (r *SnapshotRepository) Create(ctx context.Context, tx *sql.Tx, snapshot *Snapshot) error {
	query := `
		INSERT INTO snapshots (id, hostname, vaultik_version, started_at, completed_at, file_count, chunk_count, blob_count, total_size, blob_size, compression_ratio)
		VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?)
	`

	var completedAt *int64
	if snapshot.CompletedAt != nil {
		ts := snapshot.CompletedAt.Unix()
		completedAt = &ts
	}

	var err error
	if tx != nil {
		_, err = tx.ExecContext(ctx, query, snapshot.ID, snapshot.Hostname, snapshot.VaultikVersion, snapshot.StartedAt.Unix(),
			completedAt, snapshot.FileCount, snapshot.ChunkCount, snapshot.BlobCount, snapshot.TotalSize, snapshot.BlobSize, snapshot.CompressionRatio)
	} else {
		_, err = r.db.ExecWithLock(ctx, query, snapshot.ID, snapshot.Hostname, snapshot.VaultikVersion, snapshot.StartedAt.Unix(),
			completedAt, snapshot.FileCount, snapshot.ChunkCount, snapshot.BlobCount, snapshot.TotalSize, snapshot.BlobSize, snapshot.CompressionRatio)
	}

	if err != nil {
		return fmt.Errorf("inserting snapshot: %w", err)
	}

	return nil
}

func (r *SnapshotRepository) UpdateCounts(ctx context.Context, tx *sql.Tx, snapshotID string, fileCount, chunkCount, blobCount, totalSize, blobSize int64) error {
	compressionRatio := 1.0
	if totalSize > 0 {
		compressionRatio = float64(blobSize) / float64(totalSize)
	}

	query := `
		UPDATE snapshots 
		SET file_count = ?,
		    chunk_count = ?,
		    blob_count = ?,
		    total_size = ?,
		    blob_size = ?,
		    compression_ratio = ?
		WHERE id = ?
	`

	var err error
	if tx != nil {
		_, err = tx.ExecContext(ctx, query, fileCount, chunkCount, blobCount, totalSize, blobSize, compressionRatio, snapshotID)
	} else {
		_, err = r.db.ExecWithLock(ctx, query, fileCount, chunkCount, blobCount, totalSize, blobSize, compressionRatio, snapshotID)
	}

	if err != nil {
		return fmt.Errorf("updating snapshot: %w", err)
	}

	return nil
}

func (r *SnapshotRepository) GetByID(ctx context.Context, snapshotID string) (*Snapshot, error) {
	query := `
		SELECT id, hostname, vaultik_version, started_at, completed_at, file_count, chunk_count, blob_count, total_size, blob_size, compression_ratio
		FROM snapshots
		WHERE id = ?
	`

	var snapshot Snapshot
	var startedAtUnix int64
	var completedAtUnix *int64

	err := r.db.conn.QueryRowContext(ctx, query, snapshotID).Scan(
		&snapshot.ID,
		&snapshot.Hostname,
		&snapshot.VaultikVersion,
		&startedAtUnix,
		&completedAtUnix,
		&snapshot.FileCount,
		&snapshot.ChunkCount,
		&snapshot.BlobCount,
		&snapshot.TotalSize,
		&snapshot.BlobSize,
		&snapshot.CompressionRatio,
	)

	if err == sql.ErrNoRows {
		return nil, nil
	}
	if err != nil {
		return nil, fmt.Errorf("querying snapshot: %w", err)
	}

	snapshot.StartedAt = time.Unix(startedAtUnix, 0)
	if completedAtUnix != nil {
		t := time.Unix(*completedAtUnix, 0)
		snapshot.CompletedAt = &t
	}

	return &snapshot, nil
}

func (r *SnapshotRepository) ListRecent(ctx context.Context, limit int) ([]*Snapshot, error) {
	query := `
		SELECT id, hostname, vaultik_version, started_at, completed_at, file_count, chunk_count, blob_count, total_size, blob_size, compression_ratio
		FROM snapshots
		ORDER BY started_at DESC
		LIMIT ?
	`

	rows, err := r.db.conn.QueryContext(ctx, query, limit)
	if err != nil {
		return nil, fmt.Errorf("querying snapshots: %w", err)
	}
	defer CloseRows(rows)

	var snapshots []*Snapshot
	for rows.Next() {
		var snapshot Snapshot
		var startedAtUnix int64
		var completedAtUnix *int64

		err := rows.Scan(
			&snapshot.ID,
			&snapshot.Hostname,
			&snapshot.VaultikVersion,
			&startedAtUnix,
			&completedAtUnix,
			&snapshot.FileCount,
			&snapshot.ChunkCount,
			&snapshot.BlobCount,
			&snapshot.TotalSize,
			&snapshot.BlobSize,
			&snapshot.CompressionRatio,
		)
		if err != nil {
			return nil, fmt.Errorf("scanning snapshot: %w", err)
		}

		snapshot.StartedAt = time.Unix(startedAtUnix, 0)
		if completedAtUnix != nil {
			t := time.Unix(*completedAtUnix, 0)
			snapshot.CompletedAt = &t
		}

		snapshots = append(snapshots, &snapshot)
	}

	return snapshots, rows.Err()
}

// MarkComplete marks a snapshot as completed with the current timestamp
func (r *SnapshotRepository) MarkComplete(ctx context.Context, tx *sql.Tx, snapshotID string) error {
	query := `
		UPDATE snapshots 
		SET completed_at = ?
		WHERE id = ?
	`

	completedAt := time.Now().Unix()

	var err error
	if tx != nil {
		_, err = tx.ExecContext(ctx, query, completedAt, snapshotID)
	} else {
		_, err = r.db.ExecWithLock(ctx, query, completedAt, snapshotID)
	}

	if err != nil {
		return fmt.Errorf("marking snapshot complete: %w", err)
	}

	return nil
}

// AddFile adds a file to a snapshot
func (r *SnapshotRepository) AddFile(ctx context.Context, tx *sql.Tx, snapshotID string, filePath string) error {
	query := `
		INSERT OR IGNORE INTO snapshot_files (snapshot_id, file_path)
		VALUES (?, ?)
	`

	var err error
	if tx != nil {
		_, err = tx.ExecContext(ctx, query, snapshotID, filePath)
	} else {
		_, err = r.db.ExecWithLock(ctx, query, snapshotID, filePath)
	}

	if err != nil {
		return fmt.Errorf("adding file to snapshot: %w", err)
	}

	return nil
}

// AddBlob adds a blob to a snapshot
func (r *SnapshotRepository) AddBlob(ctx context.Context, tx *sql.Tx, snapshotID string, blobID string, blobHash string) error {
	query := `
		INSERT OR IGNORE INTO snapshot_blobs (snapshot_id, blob_id, blob_hash)
		VALUES (?, ?, ?)
	`

	var err error
	if tx != nil {
		_, err = tx.ExecContext(ctx, query, snapshotID, blobID, blobHash)
	} else {
		_, err = r.db.ExecWithLock(ctx, query, snapshotID, blobID, blobHash)
	}

	if err != nil {
		return fmt.Errorf("adding blob to snapshot: %w", err)
	}

	return nil
}

// GetBlobHashes returns all blob hashes for a snapshot
func (r *SnapshotRepository) GetBlobHashes(ctx context.Context, snapshotID string) ([]string, error) {
	query := `
		SELECT sb.blob_hash 
		FROM snapshot_blobs sb
		WHERE sb.snapshot_id = ?
		ORDER BY sb.blob_hash
	`

	rows, err := r.db.conn.QueryContext(ctx, query, snapshotID)
	if err != nil {
		return nil, fmt.Errorf("querying blob hashes: %w", err)
	}
	defer CloseRows(rows)

	var blobs []string
	for rows.Next() {
		var blobHash string
		if err := rows.Scan(&blobHash); err != nil {
			return nil, fmt.Errorf("scanning blob hash: %w", err)
		}
		blobs = append(blobs, blobHash)
	}

	return blobs, rows.Err()
}

// GetIncompleteSnapshots returns all snapshots that haven't been completed
func (r *SnapshotRepository) GetIncompleteSnapshots(ctx context.Context) ([]*Snapshot, error) {
	query := `
		SELECT id, hostname, vaultik_version, started_at, completed_at, file_count, chunk_count, blob_count, total_size, blob_size, compression_ratio
		FROM snapshots
		WHERE completed_at IS NULL
		ORDER BY started_at DESC
	`

	rows, err := r.db.conn.QueryContext(ctx, query)
	if err != nil {
		return nil, fmt.Errorf("querying incomplete snapshots: %w", err)
	}
	defer CloseRows(rows)

	var snapshots []*Snapshot
	for rows.Next() {
		var snapshot Snapshot
		var startedAtUnix int64
		var completedAtUnix *int64

		err := rows.Scan(
			&snapshot.ID,
			&snapshot.Hostname,
			&snapshot.VaultikVersion,
			&startedAtUnix,
			&completedAtUnix,
			&snapshot.FileCount,
			&snapshot.ChunkCount,
			&snapshot.BlobCount,
			&snapshot.TotalSize,
			&snapshot.BlobSize,
			&snapshot.CompressionRatio,
		)
		if err != nil {
			return nil, fmt.Errorf("scanning snapshot: %w", err)
		}

		snapshot.StartedAt = time.Unix(startedAtUnix, 0)
		if completedAtUnix != nil {
			t := time.Unix(*completedAtUnix, 0)
			snapshot.CompletedAt = &t
		}

		snapshots = append(snapshots, &snapshot)
	}

	return snapshots, rows.Err()
}