package store

import (
	"database/sql"
	"fmt"

	"g.fc.run/ai/byre/internal/ids"
)

func migrateRunTasks(tx *sql.Tx, _ string) error {
	rows, err := tx.Query(`SELECT workflow_run FROM tasks WHERE workflow_run != '' GROUP BY workflow_run ORDER BY min(rowid)`)
	if err != nil {
		return err
	}
	runs := []string{}
	for rows.Next() {
		run := ""
		err = rows.Scan(&run)
		if err != nil {
			rows.Close()
			return err
		}
		runs = append(runs, run)
	}
	rows.Close()
	err = rows.Err()
	if err != nil {
		return err
	}

	for _, run := range runs {
		id := ids.Derive(ids.Task, run)
		_, err = tx.Exec(`
			INSERT INTO tasks (id, project_id, title, branch, worktree_path, base_ref, status, created_by, created_at, closed_at, todo_item, color,
				workflow_name, workflow_definition_id, workflow_brief, workflow_title, audit)
			SELECT ?1, f.project_id, f.workflow_title, '', '', '',
				CASE
					WHEN EXISTS (SELECT 1 FROM tasks s WHERE s.workflow_run = ?2 AND s.status = 'active') THEN 'active'
					WHEN EXISTS (SELECT 1 FROM tasks s WHERE s.workflow_run = ?2 AND s.status = 'merged') THEN 'merged'
					ELSE 'discarded'
				END,
				f.created_by, f.created_at,
				CASE WHEN EXISTS (SELECT 1 FROM tasks s WHERE s.workflow_run = ?2 AND s.status = 'active') THEN NULL
					ELSE (SELECT max(s.closed_at) FROM tasks s WHERE s.workflow_run = ?2) END,
				f.todo_item, f.color, f.workflow_name, f.workflow_definition_id, f.workflow_brief, f.workflow_title, f.audit
			FROM tasks f WHERE f.workflow_run = ?2 ORDER BY f.created_at LIMIT 1`, id, run)
		if err != nil {
			return fmt.Errorf("run %s: %w", run, err)
		}
		_, err = tx.Exec(`
			UPDATE events SET task_id = ?1, payload = json_set(payload, '$.id', ?1)
			WHERE kind = 'task.workflow_finished' AND task_id IN (SELECT id FROM tasks WHERE workflow_run = ?2)`, id, run)
		if err != nil {
			return fmt.Errorf("run %s: %w", run, err)
		}
		_, err = tx.Exec(`
			UPDATE tasks SET parent_task_id = ?1, workflow_name = '', workflow_definition_id = NULL, workflow_brief = '', workflow_title = '', audit = '', todo_item = ''
			WHERE workflow_run = ?2`, id, run)
		if err != nil {
			return fmt.Errorf("run %s: %w", run, err)
		}
		_, err = tx.Exec(`UPDATE tasks SET state = `+taskStateExpr+` WHERE id = ?`, id)
		if err != nil {
			return fmt.Errorf("run %s: %w", run, err)
		}
	}

	_, err = tx.Exec(`ALTER TABLE tasks DROP COLUMN workflow_run`)
	return err
}