projax/store/task.go

package store

import (
	"context"
	"time"
)

// Phase 7 — Task is the uniform view-shape for a unit of work attached to a
// projax item, materialised from EITHER a CalDAV VTODO or an mBrian
// type=['task'] node. One shape, two sources; writes dispatch on Source
// (design §3.3, the slice-B "one Item shape, two backends" pattern applied
// to tasks). Consumers (the detail Tasks section, future dashboard/timeline
// rollups) render the uniform shape and don't care which backend produced it.
type Task struct {
	// ID is a stable per-source identifier: the mBrian node uuid for an
	// mBrian-native task, the VTODO UID for a CalDAV task. Unique within a
	// source; templates key rows on it.
	ID    string
	Title string
	Done  bool
	Due   *time.Time
	// Source is "mbrian" or "caldav" — write handlers dispatch on it.
	Source string
	// Status is the raw lifecycle status for mBrian tasks (active|done|
	// archived). For CalDAV tasks it carries the VTODO STATUS verbatim
	// (NEEDS-ACTION|IN-PROCESS|COMPLETED|CANCELLED) for callers that want it;
	// Done is the normalised boolean either way.
	Status string
	// ParentItemID is the projax item this task hangs under.
	ParentItemID string
	CreatedAt    time.Time

	// --- mBrian-source handle (Source == TaskSourceMBrian) ---
	// NodeID is the mBrian node uuid (== ID); the write API targets it.
	NodeID string
	Slug   string

	// --- CalDAV-source handle (Source == TaskSourceCalDAV) ---
	// CalendarURL + UID address the VTODO for ETag-guarded writeback via the
	// existing caldav write path.
	CalendarURL string
	UID         string
}

// Task source discriminators.
const (
	TaskSourceMBrian = "mbrian"
	TaskSourceCalDAV = "caldav"
)

// TaskCreateInput captures the editable surface of a new mBrian-native task.
// CalDAV tasks are created through the existing CalDAV write path (VTODO PUT),
// not this shape — only the mBrian backend creates task nodes.
type TaskCreateInput struct {
	Title        string
	Slug         string
	ParentItemID string     // the project (or task) this task attaches to via child_of
	Due          *time.Time // optional
}

// TaskReader is the read-path contract for mBrian-native task nodes. It is a
// capability SEPARATE from ItemReader: only the mBrian backend has task nodes,
// so the legacy *Store does not implement it. Web handlers obtain it via a
// type-assertion on the active Items backend (see Server.taskBackend).
type TaskReader interface {
	// TasksForItem returns the mBrian-native tasks (type=['task'] nodes)
	// attached to itemID via a child_of edge, in created-at order (Q5 —
	// created order only; no manual reorder in v1).
	TasksForItem(ctx context.Context, itemID string) ([]*Task, error)
}

// TaskWriter is the write-path contract for mBrian-native task nodes. Twin of
// TaskReader; implemented only by the mBrian backend (*MBrianWriter). Writes
// funnel through mBrian's scoped /api/projax HTTP surface so projax-created
// task nodes are byte-identical to UI/MCP/migration nodes (the slice-C
// discipline). Delete reuses the node soft-delete the API already exposes.
type TaskWriter interface {
	// CreateTask POSTs a type=['task'] node (slug honored, metadata.projax
	// carrying status/due) then attaches it to ParentItemID via a child_of
	// edge, and returns the materialised Task.
	CreateTask(ctx context.Context, in TaskCreateInput) (*Task, error)
	// SetTaskStatus PATCHes metadata.projax.status (done|active|archived) —
	// task done-state reuses the existing lifecycle (Q2), no separate field.
	SetTaskStatus(ctx context.Context, nodeID, status string) error
	// SetTaskDue PATCHes metadata.projax.due; a nil due clears it.
	SetTaskDue(ctx context.Context, nodeID string, due *time.Time) error
	// EditTaskTitle PATCHes the node title.
	EditTaskTitle(ctx context.Context, nodeID, title string) error
	// DeleteTask soft-deletes the task node.
	DeleteTask(ctx context.Context, nodeID string) error
}