package main

import (
	"bufio"
	"fmt"
	"os"
	"strings"
)

// cmdChat is the interactive terminal chat loop.
// First positional arg (if any) becomes the system prompt.
func cmdChat(args []string) error {
	if !healthCheck() {
		return fmt.Errorf("serveur injoignable sur :%d — jean start d'abord", LLMPort())
	}
	sysPrompt := strings.Join(args, " ")
	msgs := []Message{}
	if sysPrompt != "" {
		msgs = append(msgs, Message{Role: "system", Content: sysPrompt})
	}
	fmt.Printf("\n%s  —  /reset pour vider, /sys <prompt> pour changer le system, /quit ou Ctrl-D pour sortir\n", cyan("jean chat"))
	if sysPrompt != "" {
		fmt.Println(dim("system: " + sysPrompt))
	}
	fmt.Println()
	sc := bufio.NewScanner(os.Stdin)
	sc.Buffer(make([]byte, 0, 64*1024), 1<<20)
	for {
		fmt.Print(bold("you") + " > ")
		if !sc.Scan() {
			fmt.Println()
			return nil
		}
		user := sc.Text()
		u := strings.TrimSpace(user)
		if u == "" {
			continue
		}
		if u == "/quit" || u == "/exit" {
			return nil
		}
		if u == "/reset" {
			kept := []Message{}
			for _, m := range msgs {
				if m.Role == "system" {
					kept = append(kept, m)
				}
			}
			msgs = kept
			fmt.Println(dim("[contexte vidé]"))
			continue
		}
		if strings.HasPrefix(u, "/sys ") {
			newSys := strings.TrimSpace(u[5:])
			msgs = msgs[:0]
			if newSys != "" {
				msgs = append(msgs, Message{Role: "system", Content: newSys})
			}
			fmt.Println(dim("[system mis à jour]"))
			continue
		}
		msgs = append(msgs, Message{Role: "user", Content: user})
		full := strings.Builder{}
		inReason := false
		var stats *StatsEvent
		// Print the assistant prefix once; reasoning is shown inline with a tag.
		fmt.Print(cyan("jean") + " > ")
		err := runChat(InjectSkills(msgs), 0.7, func(ev StreamEvent) bool {
			switch {
			case ev.Err != nil:
				fmt.Printf("\n%s\n", red("[erreur] "+ev.Err.Error()))
			case ev.Stats != nil:
				stats = ev.Stats
			case ev.ToolUsed != nil:
				icon := "📖"
				verb := "lecture du skill"
				if ev.ToolUsed.Name == "run_shell" {
					icon = "⚙️"
					verb = "exécution"
				}
				if inReason {
					fmt.Print("\n")
					inReason = false
				}
				fmt.Printf("\n%s %s : %s\n%s ", dim(icon+" "+verb), "", magenta(ev.ToolUsed.Label), cyan("jean")+" >")
			case ev.Reasoning != "":
				if !inReason {
					fmt.Print(magenta("[reasoning] ") + dim(""))
					inReason = true
				}
				fmt.Print(dim(ev.Reasoning))
			case ev.Content != "":
				if inReason {
					fmt.Print("\n" + cyan("jean") + " > ")
					inReason = false
				}
				full.WriteString(ev.Content)
				fmt.Print(ev.Content)
			}
			return true
		})
		if inReason {
			fmt.Println()
		}
		fmt.Println()
		if stats != nil {
			fmt.Printf("%s prefill %d tok · %.0f tok/s   decode %d tok · %.1f tok/s\n",
				dim("→"), stats.PromptTokens, stats.PromptPerSecond, stats.GenTokens, stats.GenPerSecond)
		}
		fmt.Println()
		if err == nil {
			msgs = append(msgs, Message{Role: "assistant", Content: full.String()})
		}
	}
}