package dolt

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

	"github.com/steveyegge/beads/internal/storage"
	"github.com/steveyegge/beads/internal/types"
)

// doltTransaction implements storage.Transaction for Dolt
type doltTransaction struct {
	tx    *sql.Tx
	store *DoltStore
}

// RunInTransaction executes a function within a database transaction
func (s *DoltStore) RunInTransaction(ctx context.Context, fn func(tx storage.Transaction) error) error {
	sqlTx, err := s.db.BeginTx(ctx, nil)
	if err != nil {
		return fmt.Errorf("failed to begin transaction: %w", err)
	}

	tx := &doltTransaction{tx: sqlTx, store: s}

	defer func() {
		if r := recover(); r != nil {
			_ = sqlTx.Rollback()
			panic(r)
		}
	}()

	if err := fn(tx); err != nil {
		_ = sqlTx.Rollback()
		return err
	}

	return sqlTx.Commit()
}

// CreateIssue creates an issue within the transaction
func (t *doltTransaction) CreateIssue(ctx context.Context, issue *types.Issue, actor string) error {
	now := time.Now().UTC()
	if issue.CreatedAt.IsZero() {
		issue.CreatedAt = now
	}
	if issue.UpdatedAt.IsZero() {
		issue.UpdatedAt = now
	}
	if issue.ContentHash == "" {
		issue.ContentHash = issue.ComputeContentHash()
	}

	return insertIssueTx(ctx, t.tx, issue)
}

// CreateIssues creates multiple issues within the transaction
func (t *doltTransaction) CreateIssues(ctx context.Context, issues []*types.Issue, actor string) error {
	for _, issue := range issues {
		if err := t.CreateIssue(ctx, issue, actor); err != nil {
			return err
		}
	}
	return nil
}

// GetIssue retrieves an issue within the transaction
func (t *doltTransaction) GetIssue(ctx context.Context, id string) (*types.Issue, error) {
	return scanIssueTx(ctx, t.tx, id)
}

// SearchIssues searches for issues within the transaction
func (t *doltTransaction) SearchIssues(ctx context.Context, query string, filter types.IssueFilter) ([]*types.Issue, error) {
	// Simplified search for transaction context
	whereClauses := []string{}
	args := []interface{}{}

	if query != "" {
		whereClauses = append(whereClauses, "(title LIKE ? OR description LIKE ? OR id LIKE ?)")
		pattern := "%" + query + "%"
		args = append(args, pattern, pattern, pattern)
	}

	if filter.Status != nil {
		whereClauses = append(whereClauses, "status = ?")
		args = append(args, *filter.Status)
	}

	whereSQL := ""
	if len(whereClauses) > 0 {
		whereSQL = "WHERE " + strings.Join(whereClauses, " AND ")
	}

	rows, err := t.tx.QueryContext(ctx, fmt.Sprintf(`
		SELECT id FROM issues %s ORDER BY priority ASC, created_at DESC
	`, whereSQL), args...)
	if err != nil {
		return nil, err
	}
	defer rows.Close()

	var issues []*types.Issue
	for rows.Next() {
		var id string
		if err := rows.Scan(&id); err != nil {
			return nil, err
		}
		issue, err := t.GetIssue(ctx, id)
		if err != nil {
			return nil, err
		}
		if issue != nil {
			issues = append(issues, issue)
		}
	}
	return issues, rows.Err()
}

// UpdateIssue updates an issue within the transaction
func (t *doltTransaction) UpdateIssue(ctx context.Context, id string, updates map[string]interface{}, actor string) error {
	setClauses := []string{"updated_at = ?"}
	args := []interface{}{time.Now().UTC()}

	for key, value := range updates {
		if !isAllowedUpdateField(key) {
			return fmt.Errorf("invalid field for update: %s", key)
		}
		columnName := key
		if key == "wisp" {
			columnName = "ephemeral"
		}
		setClauses = append(setClauses, fmt.Sprintf("`%s` = ?", columnName))
		args = append(args, value)
	}

	args = append(args, id)
	// nolint:gosec // G201: setClauses contains only column names (e.g. "status = ?"), actual values passed via args
	query := fmt.Sprintf("UPDATE issues SET %s WHERE id = ?", strings.Join(setClauses, ", "))
	_, err := t.tx.ExecContext(ctx, query, args...)
	return err
}

// CloseIssue closes an issue within the transaction
func (t *doltTransaction) CloseIssue(ctx context.Context, id string, reason string, actor string, session string) error {
	now := time.Now().UTC()
	_, err := t.tx.ExecContext(ctx, `
		UPDATE issues SET status = ?, closed_at = ?, updated_at = ?, close_reason = ?, closed_by_session = ?
		WHERE id = ?
	`, types.StatusClosed, now, now, reason, session, id)
	return err
}

// DeleteIssue deletes an issue within the transaction
func (t *doltTransaction) DeleteIssue(ctx context.Context, id string) error {
	_, err := t.tx.ExecContext(ctx, "DELETE FROM issues WHERE id = ?", id)
	return err
}

// AddDependency adds a dependency within the transaction
func (t *doltTransaction) AddDependency(ctx context.Context, dep *types.Dependency, actor string) error {
	_, err := t.tx.ExecContext(ctx, `
		INSERT INTO dependencies (issue_id, depends_on_id, type, created_at, created_by, thread_id)
		VALUES (?, ?, ?, NOW(), ?, ?)
		ON DUPLICATE KEY UPDATE type = VALUES(type)
	`, dep.IssueID, dep.DependsOnID, dep.Type, actor, dep.ThreadID)
	return err
}

// RemoveDependency removes a dependency within the transaction
func (t *doltTransaction) RemoveDependency(ctx context.Context, issueID, dependsOnID string, actor string) error {
	_, err := t.tx.ExecContext(ctx, `
		DELETE FROM dependencies WHERE issue_id = ? AND depends_on_id = ?
	`, issueID, dependsOnID)
	return err
}

// AddLabel adds a label within the transaction
func (t *doltTransaction) AddLabel(ctx context.Context, issueID, label, actor string) error {
	_, err := t.tx.ExecContext(ctx, `
		INSERT IGNORE INTO labels (issue_id, label) VALUES (?, ?)
	`, issueID, label)
	return err
}

// RemoveLabel removes a label within the transaction
func (t *doltTransaction) RemoveLabel(ctx context.Context, issueID, label, actor string) error {
	_, err := t.tx.ExecContext(ctx, `
		DELETE FROM labels WHERE issue_id = ? AND label = ?
	`, issueID, label)
	return err
}

// SetConfig sets a config value within the transaction
func (t *doltTransaction) SetConfig(ctx context.Context, key, value string) error {
	_, err := t.tx.ExecContext(ctx, `
		INSERT INTO config (`+"`key`"+`, value) VALUES (?, ?)
		ON DUPLICATE KEY UPDATE value = VALUES(value)
	`, key, value)
	return err
}

// GetConfig gets a config value within the transaction
func (t *doltTransaction) GetConfig(ctx context.Context, key string) (string, error) {
	var value string
	err := t.tx.QueryRowContext(ctx, "SELECT value FROM config WHERE `key` = ?", key).Scan(&value)
	if err == sql.ErrNoRows {
		return "", nil
	}
	return value, err
}

// SetMetadata sets a metadata value within the transaction
func (t *doltTransaction) SetMetadata(ctx context.Context, key, value string) error {
	_, err := t.tx.ExecContext(ctx, `
		INSERT INTO metadata (`+"`key`"+`, value) VALUES (?, ?)
		ON DUPLICATE KEY UPDATE value = VALUES(value)
	`, key, value)
	return err
}

// GetMetadata gets a metadata value within the transaction
func (t *doltTransaction) GetMetadata(ctx context.Context, key string) (string, error) {
	var value string
	err := t.tx.QueryRowContext(ctx, "SELECT value FROM metadata WHERE `key` = ?", key).Scan(&value)
	if err == sql.ErrNoRows {
		return "", nil
	}
	return value, err
}

// AddComment adds a comment within the transaction
func (t *doltTransaction) AddComment(ctx context.Context, issueID, actor, comment string) error {
	_, err := t.tx.ExecContext(ctx, `
		INSERT INTO events (issue_id, event_type, actor, comment)
		VALUES (?, ?, ?, ?)
	`, issueID, types.EventCommented, actor, comment)
	return err
}

// Helper functions for transaction context

func insertIssueTx(ctx context.Context, tx *sql.Tx, issue *types.Issue) error {
	_, err := tx.ExecContext(ctx, `
		INSERT INTO issues (
			id, content_hash, title, description, design, acceptance_criteria, notes,
			status, priority, issue_type, assignee, estimated_minutes,
			created_at, created_by, owner, updated_at, closed_at,
			sender, ephemeral, pinned, is_template, crystallizes
		) VALUES (
			?, ?, ?, ?, ?, ?, ?,
			?, ?, ?, ?, ?,
			?, ?, ?, ?, ?,
			?, ?, ?, ?, ?
		)
	`,
		issue.ID, issue.ContentHash, issue.Title, issue.Description, issue.Design, issue.AcceptanceCriteria, issue.Notes,
		issue.Status, issue.Priority, issue.IssueType, nullString(issue.Assignee), nullInt(issue.EstimatedMinutes),
		issue.CreatedAt, issue.CreatedBy, issue.Owner, issue.UpdatedAt, issue.ClosedAt,
		issue.Sender, issue.Ephemeral, issue.Pinned, issue.IsTemplate, issue.Crystallizes,
	)
	return err
}

func scanIssueTx(ctx context.Context, tx *sql.Tx, id string) (*types.Issue, error) {
	var issue types.Issue
	var closedAt sql.NullTime
	var estimatedMinutes sql.NullInt64
	var assignee, owner, contentHash sql.NullString
	var ephemeral, pinned, isTemplate, crystallizes sql.NullInt64

	err := tx.QueryRowContext(ctx, `
		SELECT id, content_hash, title, description, design, acceptance_criteria, notes,
		       status, priority, issue_type, assignee, estimated_minutes,
		       created_at, created_by, owner, updated_at, closed_at,
		       ephemeral, pinned, is_template, crystallizes
		FROM issues
		WHERE id = ?
	`, id).Scan(
		&issue.ID, &contentHash, &issue.Title, &issue.Description, &issue.Design,
		&issue.AcceptanceCriteria, &issue.Notes, &issue.Status,
		&issue.Priority, &issue.IssueType, &assignee, &estimatedMinutes,
		&issue.CreatedAt, &issue.CreatedBy, &owner, &issue.UpdatedAt, &closedAt,
		&ephemeral, &pinned, &isTemplate, &crystallizes,
	)

	if err == sql.ErrNoRows {
		return nil, nil
	}
	if err != nil {
		return nil, err
	}

	if contentHash.Valid {
		issue.ContentHash = contentHash.String
	}
	if closedAt.Valid {
		issue.ClosedAt = &closedAt.Time
	}
	if estimatedMinutes.Valid {
		mins := int(estimatedMinutes.Int64)
		issue.EstimatedMinutes = &mins
	}
	if assignee.Valid {
		issue.Assignee = assignee.String
	}
	if owner.Valid {
		issue.Owner = owner.String
	}
	if ephemeral.Valid && ephemeral.Int64 != 0 {
		issue.Ephemeral = true
	}
	if pinned.Valid && pinned.Int64 != 0 {
		issue.Pinned = true
	}
	if isTemplate.Valid && isTemplate.Int64 != 0 {
		issue.IsTemplate = true
	}
	if crystallizes.Valid && crystallizes.Int64 != 0 {
		issue.Crystallizes = true
	}

	return &issue, nil
}