package api

import (
	"bytes"
	"encoding/json"
	"fmt"
	"net/http"
	"net/http/httptest"
	"os"
	"path/filepath"
	"strings"
	"testing"
)

// createFakeClaude writes a shell script to a temp dir that prints output and exits with the
// given code. Returns the script path. Used to mock the claude binary in elaborate tests.
func createFakeClaude(t *testing.T, output string, exitCode int) string {
	t.Helper()
	dir := t.TempDir()
	outputFile := filepath.Join(dir, "output.json")
	if err := os.WriteFile(outputFile, []byte(output), 0600); err != nil {
		t.Fatal(err)
	}
	script := filepath.Join(dir, "claude")
	content := fmt.Sprintf("#!/bin/sh\ncat %q\nexit %d\n", outputFile, exitCode)
	if err := os.WriteFile(script, []byte(content), 0755); err != nil {
		t.Fatal(err)
	}
	return script
}

func TestElaboratePrompt_ContainsWorkDir(t *testing.T) {
	prompt := buildElaboratePrompt("/some/custom/path")
	if !strings.Contains(prompt, "/some/custom/path") {
		t.Error("prompt should contain the provided workDir")
	}
	if strings.Contains(prompt, "/root/workspace/claudomator") {
		t.Error("prompt should not hardcode /root/workspace/claudomator")
	}
}

func TestElaboratePrompt_EmptyWorkDir(t *testing.T) {
	prompt := buildElaboratePrompt("")
	if strings.Contains(prompt, "/root") {
		t.Error("prompt should not reference /root when workDir is empty")
	}
}

func TestElaborateTask_Success(t *testing.T) {
	srv, _ := testServer(t)

	// Build fake Claude output: {"result": "<task-json>"}
	task := elaboratedTask{
		Name:        "Run Go tests with race detector",
		Description: "Runs the Go test suite with -race flag and checks coverage.",
		Agent: elaboratedAgent{
			Type:         "claude",
			Model:        "sonnet",
			Instructions: "Run go test -race ./... and report results.",
			WorkingDir:   "",
			MaxBudgetUSD: 0.5,
			AllowedTools: []string{"Bash"},
		},
		Timeout:  "15m",
		Priority: "normal",
		Tags:     []string{"testing", "ci"},
	}
	taskJSON, err := json.Marshal(task)
	if err != nil {
		t.Fatal(err)
	}
	wrapper := map[string]string{"result": string(taskJSON)}
	wrapperJSON, err := json.Marshal(wrapper)
	if err != nil {
		t.Fatal(err)
	}

	srv.elaborateCmdPath = createFakeClaude(t, string(wrapperJSON), 0)

	body := `{"prompt":"run the Go test suite with race detector and fail if coverage < 80%"}`
	req := httptest.NewRequest("POST", "/api/tasks/elaborate", bytes.NewBufferString(body))
	req.Header.Set("Content-Type", "application/json")
	w := httptest.NewRecorder()

	srv.Handler().ServeHTTP(w, req)

	if w.Code != http.StatusOK {
		t.Fatalf("status: want 200, got %d; body: %s", w.Code, w.Body.String())
	}

	var result elaboratedTask
	if err := json.NewDecoder(w.Body).Decode(&result); err != nil {
		t.Fatalf("failed to decode response: %v", err)
	}
	if result.Name == "" {
		t.Error("expected non-empty name")
	}
	if result.Agent.Instructions == "" {
		t.Error("expected non-empty instructions")
	}
}

func TestElaborateTask_EmptyPrompt(t *testing.T) {
	srv, _ := testServer(t)

	body := `{"prompt":""}`
	req := httptest.NewRequest("POST", "/api/tasks/elaborate", bytes.NewBufferString(body))
	req.Header.Set("Content-Type", "application/json")
	w := httptest.NewRecorder()

	srv.Handler().ServeHTTP(w, req)

	if w.Code != http.StatusBadRequest {
		t.Fatalf("status: want 400, got %d; body: %s", w.Code, w.Body.String())
	}

	var resp map[string]string
	json.NewDecoder(w.Body).Decode(&resp)
	if resp["error"] == "" {
		t.Error("expected error message in response")
	}
}

func TestElaborateTask_MarkdownFencedJSON(t *testing.T) {
	srv, _ := testServer(t)

	// Build a valid task JSON but wrap it in markdown fences as haiku sometimes does.
	task := elaboratedTask{
		Name:        "Test task",
		Description: "Does something.",
		Agent: elaboratedAgent{
			Type:         "claude",
			Model:        "sonnet",
			Instructions: "Do the thing.",
			MaxBudgetUSD: 0.5,
			AllowedTools: []string{"Bash"},
		},
		Timeout:  "15m",
		Priority: "normal",
		Tags:     []string{"test"},
	}
	taskJSON, _ := json.Marshal(task)
	fenced := "```json\n" + string(taskJSON) + "\n```"
	wrapper := map[string]string{"result": fenced}
	wrapperJSON, _ := json.Marshal(wrapper)

	srv.elaborateCmdPath = createFakeClaude(t, string(wrapperJSON), 0)

	body := `{"prompt":"do something"}`
	req := httptest.NewRequest("POST", "/api/tasks/elaborate", bytes.NewBufferString(body))
	req.Header.Set("Content-Type", "application/json")
	w := httptest.NewRecorder()

	srv.Handler().ServeHTTP(w, req)

	if w.Code != http.StatusOK {
		t.Fatalf("status: want 200, got %d; body: %s", w.Code, w.Body.String())
	}

	var result elaboratedTask
	if err := json.NewDecoder(w.Body).Decode(&result); err != nil {
		t.Fatalf("failed to decode response: %v", err)
	}
	if result.Name != task.Name {
		t.Errorf("name: want %q, got %q", task.Name, result.Name)
	}
}

func TestElaborateTask_InvalidJSONFromClaude(t *testing.T) {
	srv, _ := testServer(t)

	// Fake Claude returns something that is not valid JSON.
	srv.elaborateCmdPath = createFakeClaude(t, "not valid json at all", 0)

	body := `{"prompt":"do something"}`
	req := httptest.NewRequest("POST", "/api/tasks/elaborate", bytes.NewBufferString(body))
	req.Header.Set("Content-Type", "application/json")
	w := httptest.NewRecorder()

	srv.Handler().ServeHTTP(w, req)

	if w.Code != http.StatusBadGateway {
		t.Fatalf("status: want 502, got %d; body: %s", w.Code, w.Body.String())
	}

	var resp map[string]string
	json.NewDecoder(w.Body).Decode(&resp)
	if resp["error"] == "" {
		t.Error("expected error message in response")
	}
}