package store

import (
	"encoding/json"
	"fmt"
	"os"
	"path/filepath"

	"superwork-tui/internal/config"
)

// ManagedSession is a Claude session created via the session manager tab.
type ManagedSession struct {
	ID          string `json:"id"`
	Name        string `json:"name"`
	ProfilePath string `json:"profilePath,omitempty"`
	CreatedAt   int64  `json:"createdAt"`
}

// ManagedSessionsData is the workspace-level managed sessions list.
type ManagedSessionsData struct {
	Sessions []ManagedSession `json:"sessions"`
}

func sessionsFile(workspaceRoot string) string {
	return filepath.Join(config.SpxDir(workspaceRoot), "session-names.json")
}

// ReadManagedSessions reads the managed sessions list.
// A missing or malformed file returns an empty list without error.
func ReadManagedSessions(workspaceRoot string) (ManagedSessionsData, error) {
	raw, err := os.ReadFile(sessionsFile(workspaceRoot))
	if err != nil {
		return ManagedSessionsData{Sessions: []ManagedSession{}}, nil
	}
	var data ManagedSessionsData
	if err := json.Unmarshal(raw, &data); err != nil {
		return ManagedSessionsData{Sessions: []ManagedSession{}}, nil
	}
	if data.Sessions == nil {
		data.Sessions = []ManagedSession{}
	}
	return data, nil
}

// WriteManagedSessions persists the sessions list. Creates .spx if needed.
func WriteManagedSessions(workspaceRoot string, data ManagedSessionsData) error {
	if err := os.MkdirAll(config.SpxDir(workspaceRoot), 0o755); err != nil {
		return fmt.Errorf("create .spx dir: %w", err)
	}
	b, err := json.MarshalIndent(data, "", "  ")
	if err != nil {
		return fmt.Errorf("marshal sessions: %w", err)
	}
	if err := os.WriteFile(sessionsFile(workspaceRoot), append(b, '\n'), 0o644); err != nil {
		return fmt.Errorf("write sessions: %w", err)
	}
	return nil
}

// AddSession appends s to data and returns the new data.
func AddSession(data ManagedSessionsData, s ManagedSession) ManagedSessionsData {
	out := make([]ManagedSession, len(data.Sessions), len(data.Sessions)+1)
	copy(out, data.Sessions)
	return ManagedSessionsData{Sessions: append(out, s)}
}

// RenameSession sets the Name of the session with the given id.
func RenameSession(data ManagedSessionsData, id, name string) ManagedSessionsData {
	out := make([]ManagedSession, len(data.Sessions))
	copy(out, data.Sessions)
	for i := range out {
		if out[i].ID == id {
			out[i].Name = name
			break
		}
	}
	return ManagedSessionsData{Sessions: out}
}

// DeleteSession removes the session with the given id.
func DeleteSession(data ManagedSessionsData, id string) ManagedSessionsData {
	out := make([]ManagedSession, 0, len(data.Sessions))
	for _, s := range data.Sessions {
		if s.ID != id {
			out = append(out, s)
		}
	}
	data.Sessions = out
	return data
}

// FindSession returns the session with the given id, if present.
func FindSession(data ManagedSessionsData, id string) (ManagedSession, bool) {
	for _, s := range data.Sessions {
		if s.ID == id {
			return s, true
		}
	}
	return ManagedSession{}, false
}