package storage

import (
	"crypto/sha256"
	"fmt"
	"sort"
	"sync"

	"github.com/maxence-charriere/go-app/v9/pkg/app"
)

const (
	ConversationsKey = "saltyim-conversations-%x"
)

type Conversations interface {
	Read() []string
	Append(line string)
	Update(lines []string)
	Delete()
}

type conversations struct {
	state StateOperations
	lock  *sync.Mutex
	addr  string
}

func (c *conversations) Read() []string {
	return readConversations(c.state, c.addr)
}

func (c *conversations) Update(lines []string) {
	updateConversations(c.state, c.addr, lines)
}

func (c *conversations) Append(line string) {
	existingLines := readConversations(c.state, c.addr)
	// TODO: map would be more efficient for finding existing messages
	for _, existingLine := range existingLines {
		if line == existingLine {
			return
		}
	}
	conversationLines := append(existingLines, line)
	sort.Strings(conversationLines)
	c.Update(conversationLines)
}

func (c *conversations) Delete() {
	c.state.DelState(conversationKey(c.addr))
}

func readConversations(state StateOperations, addr string) []string {
	var conversations []string
	state.GetState(conversationKey(addr), &conversations)
	return conversations
}

func conversationKey(addr string) string {
	return fmt.Sprintf(ConversationsKey, sha256.Sum256([]byte(addr)))
}
func updateConversations(state StateOperations, addr string, conversations []string) {
	state.SetState(conversationKey(addr), conversations, app.Persist, app.Encrypt)
}

func ConversationsLocalStorage(state StateOperations, addr string) Conversations {
	return &conversations{state: state, lock: &sync.Mutex{}, addr: addr}
}