package cli

import (
	"bufio"
	"context"
	"fmt"
	"io"
	"os"
	"strings"

	"email-mcp/mcpgen"
	frameworkcli "forge.lclr.dev/AI/mcp-framework/cli"

	"email-mcp/internal/secretstore"
)

type InteractiveConfigPrompter struct {
	reader    *bufio.Reader
	stdinFile *os.File
	output    io.Writer
}

func NewInteractiveConfigPrompter(input io.Reader, output io.Writer) *InteractiveConfigPrompter {
	if input == nil {
		input = strings.NewReader("")
	}
	if output == nil {
		output = io.Discard
	}

	prompter := &InteractiveConfigPrompter{
		reader: bufio.NewReader(input),
		output: output,
	}
	if file, ok := input.(*os.File); ok {
		prompter.stdinFile = file
	}

	return prompter
}

func (p *InteractiveConfigPrompter) PromptCredential(_ context.Context, existing secretstore.Credential, hasStoredPassword bool) (secretstore.Credential, error) {
	if p.stdinFile != nil {
		return p.promptCredentialWithSetupEngine(existing, hasStoredPassword)
	}

	host, err := frameworkcli.PromptLine(p.reader, p.output, "IMAP host", existing.Host)
	if err != nil {
		return secretstore.Credential{}, err
	}

	username, err := frameworkcli.PromptLine(p.reader, p.output, "Username", existing.Username)
	if err != nil {
		return secretstore.Credential{}, err
	}

	password, err := p.promptPassword(existing.Password, hasStoredPassword)
	if err != nil {
		return secretstore.Credential{}, err
	}

	cred := secretstore.Credential{
		Host:     host,
		Username: username,
		Password: password,
	}
	if err := cred.Validate(); err != nil {
		return secretstore.Credential{}, err
	}

	return cred, nil
}

func (p *InteractiveConfigPrompter) promptCredentialWithSetupEngine(existing secretstore.Credential, hasStoredPassword bool) (secretstore.Credential, error) {
	password := ""
	if hasStoredPassword {
		password = existing.Password
	}

	fields := mcpgen.SetupFields(map[string]string{"password": password})
	for i := range fields {
		switch fields[i].Name {
		case "host":
			fields[i].Default = existing.Host
		case "username":
			fields[i].Default = existing.Username
		}
	}

	result, err := frameworkcli.RunSetup(frameworkcli.SetupOptions{
		Stdin:  p.stdinFile,
		Stdout: p.output,
		Fields: fields,
	})
	if err != nil {
		return secretstore.Credential{}, err
	}

	host, ok := result.Get("host")
	if !ok {
		return secretstore.Credential{}, fmt.Errorf("setup result is missing host")
	}
	username, ok := result.Get("username")
	if !ok {
		return secretstore.Credential{}, fmt.Errorf("setup result is missing username")
	}
	secret, ok := result.Get("password")
	if !ok {
		return secretstore.Credential{}, fmt.Errorf("setup result is missing password")
	}

	cred := secretstore.Credential{
		Host:     host.String,
		Username: username.String,
		Password: secret.String,
	}
	if err := cred.Validate(); err != nil {
		return secretstore.Credential{}, err
	}

	return cred, nil
}

func (p *InteractiveConfigPrompter) promptPassword(storedPassword string, hasStoredPassword bool) (string, error) {
	if p.stdinFile != nil {
		return frameworkcli.PromptSecret(p.stdinFile, p.output, "Password", hasStoredPassword, storedPassword)
	}

	if hasStoredPassword {
		fmt.Fprint(p.output, "Password [stored, leave blank to keep]: ")
	} else {
		fmt.Fprint(p.output, "Password: ")
	}

	line, err := p.reader.ReadString('\n')
	if err != nil && err != io.EOF {
		return "", err
	}

	password := strings.TrimSpace(line)
	if password == "" && hasStoredPassword {
		return storedPassword, nil
	}

	return password, nil
}