package store

import (
	"database/sql"
	"errors"
	"fmt"

	"github.com/google/uuid"
)

const workloadColumns = `id, kind, ref_id, name, app_id,
	source_kind, source_config, trigger_kind, trigger_config,
	public_faces, parent_workload_id,
	notification_url, notification_secret,
	webhook_secret, webhook_signing_secret, webhook_require_signature,
	created_at, updated_at`

func scanWorkload(scanner interface{ Scan(...any) error }) (Workload, error) {
	var w Workload
	err := scanner.Scan(
		&w.ID, &w.Kind, &w.RefID, &w.Name, &w.AppID,
		&w.SourceKind, &w.SourceConfig, &w.TriggerKind, &w.TriggerConfig,
		&w.PublicFaces, &w.ParentWorkloadID,
		&w.NotificationURL, &w.NotificationSecret,
		&w.WebhookSecret, &w.WebhookSigningSecret, &w.WebhookRequireSignature,
		&w.CreatedAt, &w.UpdatedAt,
	)
	return w, err
}

// CreateWorkload inserts a new workload row. The (Kind, RefID) pair
// must be unique; for plugin-native rows (Kind="plugin") the caller
// typically leaves RefID empty and we self-reference it to the row's
// own ID so the UNIQUE(kind, ref_id) constraint holds for many sibling
// plugin workloads. Legacy bridge code that wired ref_id to a
// project/stack/site row was deleted in the hard cutover.
func (s *Store) CreateWorkload(w Workload) (Workload, error) {
	if w.ID == "" {
		w.ID = uuid.New().String()
	}
	if w.RefID == "" {
		w.RefID = w.ID
	}
	w.CreatedAt = Now()
	w.UpdatedAt = w.CreatedAt

	if w.SourceConfig == "" {
		w.SourceConfig = "{}"
	}
	if w.TriggerConfig == "" {
		w.TriggerConfig = "{}"
	}
	if w.PublicFaces == "" {
		w.PublicFaces = "[]"
	}
	_, err := s.db.Exec(
		`INSERT INTO workloads (`+workloadColumns+`)
		 VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?)`,
		w.ID, w.Kind, w.RefID, w.Name, w.AppID,
		w.SourceKind, w.SourceConfig, w.TriggerKind, w.TriggerConfig,
		w.PublicFaces, w.ParentWorkloadID,
		w.NotificationURL, w.NotificationSecret,
		w.WebhookSecret, w.WebhookSigningSecret, BoolToInt(w.WebhookRequireSignature),
		w.CreatedAt, w.UpdatedAt,
	)
	if err != nil {
		return Workload{}, fmt.Errorf("insert workload: %w", err)
	}
	return w, nil
}

// GetWorkloadByID returns a single workload by its ID.
func (s *Store) GetWorkloadByID(id string) (Workload, error) {
	w, err := scanWorkload(s.db.QueryRow(
		`SELECT `+workloadColumns+` FROM workloads WHERE id = ?`, id,
	))
	if errors.Is(err, sql.ErrNoRows) {
		return Workload{}, fmt.Errorf("workload %s: %w", id, ErrNotFound)
	}
	if err != nil {
		return Workload{}, fmt.Errorf("query workload: %w", err)
	}
	return w, nil
}

// GetWorkloadByRef returns the workload paired with a given (kind, ref_id).
// Returns ErrNotFound if the project/stack/site has no workload row yet
// (which means the boot-time backfill hasn't run, or the kind/ref pair is wrong).
func (s *Store) GetWorkloadByRef(kind WorkloadKind, refID string) (Workload, error) {
	w, err := scanWorkload(s.db.QueryRow(
		`SELECT `+workloadColumns+` FROM workloads WHERE kind = ? AND ref_id = ?`,
		string(kind), refID,
	))
	if errors.Is(err, sql.ErrNoRows) {
		return Workload{}, fmt.Errorf("workload (%s,%s): %w", kind, refID, ErrNotFound)
	}
	if err != nil {
		return Workload{}, fmt.Errorf("query workload by ref: %w", err)
	}
	return w, nil
}

// ListWorkloads returns all workloads, optionally filtered by kind. Pass
// empty string to get every workload regardless of kind.
func (s *Store) ListWorkloads(kind WorkloadKind) ([]Workload, error) {
	var rows *sql.Rows
	var err error
	if kind == "" {
		rows, err = s.db.Query(
			`SELECT ` + workloadColumns + ` FROM workloads ORDER BY name`,
		)
	} else {
		rows, err = s.db.Query(
			`SELECT `+workloadColumns+` FROM workloads WHERE kind = ? ORDER BY name`,
			string(kind),
		)
	}
	if err != nil {
		return nil, fmt.Errorf("query workloads: %w", err)
	}
	defer rows.Close()

	out := []Workload{}
	for rows.Next() {
		w, err := scanWorkload(rows)
		if err != nil {
			return nil, fmt.Errorf("scan workload: %w", err)
		}
		out = append(out, w)
	}
	return out, rows.Err()
}

// UpdateWorkload updates the mutable fields of a workload (name, app_id,
// source/trigger config, public faces, parent chain, notification + webhook
// config). Kind and RefID are immutable post-create.
func (s *Store) UpdateWorkload(w Workload) error {
	w.UpdatedAt = Now()
	if w.SourceConfig == "" {
		w.SourceConfig = "{}"
	}
	if w.TriggerConfig == "" {
		w.TriggerConfig = "{}"
	}
	if w.PublicFaces == "" {
		w.PublicFaces = "[]"
	}
	result, err := s.db.Exec(
		`UPDATE workloads SET name=?, app_id=?,
			source_kind=?, source_config=?, trigger_kind=?, trigger_config=?,
			public_faces=?, parent_workload_id=?,
			notification_url=?, notification_secret=?,
			webhook_secret=?, webhook_signing_secret=?, webhook_require_signature=?,
			updated_at=?
		 WHERE id=?`,
		w.Name, w.AppID,
		w.SourceKind, w.SourceConfig, w.TriggerKind, w.TriggerConfig,
		w.PublicFaces, w.ParentWorkloadID,
		w.NotificationURL, w.NotificationSecret,
		w.WebhookSecret, w.WebhookSigningSecret, BoolToInt(w.WebhookRequireSignature),
		w.UpdatedAt, w.ID,
	)
	if err != nil {
		return fmt.Errorf("update workload: %w", err)
	}
	n, err := result.RowsAffected()
	if err != nil {
		return fmt.Errorf("rows affected: %w", err)
	}
	if n == 0 {
		return fmt.Errorf("workload %s: %w", w.ID, ErrNotFound)
	}
	return nil
}

// DeleteWorkload removes a workload row. Cascading deletes for FK-backed
// child tables (workload_env, workload_volumes, workload_trigger_bindings)
// happen via SQLite's ON DELETE CASCADE. The `containers` table doesn't
// yet have an FK to workloads (planned migration — see ops notes), so we
// drop its rows explicitly here in the same transaction to prevent zombie
// container rows from outliving their owning workload.
func (s *Store) DeleteWorkload(id string) error {
	tx, err := s.db.Begin()
	if err != nil {
		return fmt.Errorf("begin: %w", err)
	}
	defer func() { _ = tx.Rollback() }()

	// Explicit container cleanup until the FK migration lands.
	if _, err := tx.Exec(`DELETE FROM containers WHERE workload_id = ?`, id); err != nil {
		return fmt.Errorf("delete containers: %w", err)
	}
	result, err := tx.Exec(`DELETE FROM workloads WHERE id = ?`, id)
	if err != nil {
		return fmt.Errorf("delete workload: %w", err)
	}
	n, err := result.RowsAffected()
	if err != nil {
		return fmt.Errorf("rows affected: %w", err)
	}
	if n == 0 {
		return fmt.Errorf("workload %s: %w", id, ErrNotFound)
	}
	if err := tx.Commit(); err != nil {
		return fmt.Errorf("commit: %w", err)
	}
	return nil
}

// ListChildrenByParent returns every workload whose parent_workload_id
// equals the given id. Used to render the stages chain ("dev → staging
// → prod") on /apps/[id] without forcing a separate stages table.
//
// Returns rows ordered by name for a stable UI.
func (s *Store) ListChildrenByParent(parentID string) ([]Workload, error) {
	if parentID == "" {
		return []Workload{}, nil
	}
	rows, err := s.db.Query(
		`SELECT `+workloadColumns+` FROM workloads WHERE parent_workload_id = ? ORDER BY name`,
		parentID,
	)
	if err != nil {
		return nil, fmt.Errorf("query workload children: %w", err)
	}
	defer rows.Close()

	out := []Workload{}
	for rows.Next() {
		w, err := scanWorkload(rows)
		if err != nil {
			return nil, fmt.Errorf("scan child workload: %w", err)
		}
		out = append(out, w)
	}
	return out, rows.Err()
}

// Workload-level webhook secret accessors (Get/Set/Ensure) were dropped
// in the hard legacy cutover: the inbound `/api/webhook/workloads/...`
// route is gone. The trigger-split refactor's boot backfill still reads
// the `workloads.webhook_secret` column directly via SQL to lift any
// pre-cutover embedded secret onto its standalone Trigger row, then the
// column is effectively dead.

// DeleteWorkloadByRef removes the workload paired with a given (kind, ref_id).
// Idempotent — returns nil if no row exists, since the kind-specific Delete
// callers don't always know whether a workload row was created.
func (s *Store) DeleteWorkloadByRef(kind WorkloadKind, refID string) error {
	_, err := s.db.Exec(
		`DELETE FROM workloads WHERE kind = ? AND ref_id = ?`,
		string(kind), refID,
	)
	if err != nil {
		return fmt.Errorf("delete workload by ref: %w", err)
	}
	return nil
}